Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis (Earth and Environmental Sciences Library) 3030640043, 9783030640040

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Earth and Environmental Sciences Library

Erina Iwasaki Abdelazim M. Negm Salwa F. Elbeih Editors

Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis

Earth and Environmental Sciences Library

Earth and Environmental Sciences Library (EESL) is a multidisciplinary book series focusing on innovative approaches and solid reviews to strengthen the role of the Earth and Environmental Sciences communities, while also providing sound guidance for stakeholders, decision-makers, policymakers, international organizations, and NGOs. Topics of interest include oceanography, the marine environment, atmospheric sciences, hydrology and soil sciences, geophysics and geology, agriculture, environmental pollution, remote sensing, climate change, water resources, and natural resources management. In pursuit of these topics, the Earth Sciences and Environmental Sciences communities are invited to share their knowledge and expertise in the form of edited books, monographs, and conference proceedings.

More information about this series at http://www.springer.com/series/16637

Erina Iwasaki · Abdelazim M. Negm · Salwa F. Elbeih Editors

Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis

Editors Erina Iwasaki Faculty of Foreign Studies Sophia University Tokyo, Japan

Abdelazim M. Negm Faculty of Engineering Zagazig University Zagazig, Egypt

Salwa F. Elbeih National Authority for Remote Sensing and Space Sciences Cairo, Egypt

ISSN 2730-6674 ISSN 2730-6682 (electronic) Earth and Environmental Sciences Library ISBN 978-3-030-64004-0 ISBN 978-3-030-64005-7 (eBook) https://doi.org/10.1007/978-3-030-64005-7 © Springer Nature Switzerland AG 2021 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Preface

This volume came into conception to highlight the sustainability of water resources in Dakhla Oasis. This unique volume is authored by experts in the topic from Egypt and Japan to present the results and findings of their research and the state of the art of knowledge related to the book title. The volume is divided into five parts and contains 16 chapters including introductory and conclusion chapters written by more than 20 authors. This book was planned to mainly publish the results of the research on Dakhla Oasis, and with the cooperation of researchers of various disciplines who have been conducting fieldworks in Dakhla Oasis to cover important topics related to the sustainable water solutions in the Dakhla Oasis. This book is a multidisciplinary manuscript bringing together contributions on water issues from natural and social scientists focusing on water management and structures in a challenging environmental situation such as Dakhla Oasis, Western Desert of Egypt. Dakhla Oasis is a challenging field for the study of sustainability and environment, because it depends upon groundwater which is almost unsustainable in nature. How can we realize sustainable development in an unsustainable water condition? This difficult paradoxical question is not relevant only to Dakhla Oasis, but also to the world in the twentieth century where the environmental problems are becoming increasingly important. Hence, although the book focuses on Dakhla Oasis in Western Desert of Egypt, it can serve as a reference for practitioners and experts of different organizations concerned with sustainability in arid regions. Equally, we hope that researchers, designers, and workers in the field of sustainability and environments covered in the book will find the text of interest and a useful reference source. The subject of water and sustainable development is a wide-ranging one, and only some of the most basic aspects and environmental problems are covered in this book. It soon became apparent that although a number of good books may be available on oasis or sustainability, no text covered the sustainable development of oasis. Thus, the idea of “Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis” book came about. By gathering the researchers, experts and scientists from Egypt and Japan of different disciplines, this book hopes to shed light on the way to keep the oasis sustainable. v

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It is worth mentioning that Erina Iwasaki (Sophia University, Japan) and Salwa Elbeih (National Authority of Remote Sensing and Space Sciences (NARSS), Egypt) have been conducting a multidisciplinary joint research in Dakhla Oasis about land use, water resources, and agriculture with focus on Rashda Village within the framework of the research project “Development of the sustainable underground water use in the water-scarce societies in North Africa” (MEXT/JSPS KAKENHI Grant Number, Project JP17H16026). Also, Abdelazim M. Negm and his team are working on a multidisciplinary project (ID 30771) that is funded by Science, Innovation and Technology Funding Association (STIFA) of Egypt. Therefore, acknowledging the support provided by STIFA is made. Moreover, several authors in this book, including Reiji Kimura (Tottori University, Japan), El-Sayed Zaghloul (National Authority of Remote Sensing and Space Sciences), and Adel Shalaby (National Authority of Remote Sensing and Space Sciences) have been part of the team for the project JP17H16026. Special thank goes to all contributors and to all who contributed in one way or another to make this book a real source of knowledge and the latest findings in the field of sustainability in Dakhla Oasis until the date of publication. We would like to thank all the authors/coauthors for their invaluable contributions. Without their patience and effort in writing and revising the texts several times based on the comments from the reviewers and Springer editors particularly Andrey Kostianoy and Alexis Vizcaino, it would not have been possible to produce this unique book and make it a reality. Much appreciation and great thanks are also owed to the editors of the Earth and Environmental Sciences series at Springer for the constructive comments, advice, and the critical reviews since the editors started the book project in July 2018. Acknowledgments are extended to include all members of the Springer team who have worked long and hard to produce this book. The volume editors would be happy to receive any comments to improve future editions. Comments, feedback, suggestions for improvement, or new chapters for next editions are welcomed and should be sent directly to the volume editors. The emails of the editors can be found inside the books at the footnote of their chapters. Tokyo, Japan Zagazig, Egypt Cairo, Egypt November 2019

Erina Iwasaki Abdelazim M. Negm Salwa F. Elbeih

Contents

Introduction Introduction to “Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abdelazim M. Negm, El-Sayed E. Omran, Erina Iwasaki, and Salwa F. Elbeih

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The Egyptian Western Desert: Water, Agriculture and Culture of Oasis Communities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Soher Hussen Ibrahem Mohamed

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Geology, Geomorphology, Archaeology and Climate Geology of Dakhla Oasis, Western Desert, Egypt . . . . . . . . . . . . . . . . . . . . . Elsayed A. Zaghloul

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Geomorphology of Dakhla Depression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Atef Moatamed A. Mohamed

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Archaeological Sites in Dakhla Oasis, Western Desert, Egypt . . . . . . . . . . Elsayed A. Zaghloul

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Climate Features of Dakhla Oasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reiji Kimura

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Land Use, Soil and Cultivation Aeolian Sand Transport Potential and Its Environmental Impact in Dakhla Oasis, Egypt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Abbas M. Sharaky Soil Conditions of Dakhla Oasis, Western Desert, Egypt . . . . . . . . . . . . . . . 123 Abdelaziz B. A. Belal, El-Sayed S. Mohamed, Mostafa A. Abdellatif, and Mohamed A. E. AbdelRahman

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Remote Sensing and GIS for Land Use/Land Cover Change Detection in Dakhla Oasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Adel Shalaby and Hossam S. Khedr Crop Diversification and Its Efficiency in Rashda Village, Dakhla Oasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Erina Iwasaki and Kenichi Kashiwagi Hydrological Aspects and Water Resources Hydrologeological and Hydrological Conditions of Dakhla Oasis . . . . . . . 185 Salwa F. Elbeih and Elsayed A. Zaghloul History of Wells in Rashda Village, Dakhla Oasis . . . . . . . . . . . . . . . . . . . . . 203 Erina Iwasaki Development of Land Use and Groundwater in Rashda Village (Dakhla Oasis), 1960s–2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 Erina Iwasaki, Adel Shalaby, Salwa F. Elbeih, and Hossam S. Khedr Detecting and Controlling the Waterlogging in Dakhla Basin . . . . . . . . . . 241 El-Sayed E. Omran Hydrogeophysical Investigations Using DC Resistivity Survey to Assess the Water Potentialities of the Shallow Aquifer Zone in East of Dakhla Oasis, Egypt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Khaled S. Gemail, Alaa A. Masoud, Mohamed M. El-Horiny, Mohamed G. Atwia, and Katsuaki Koike Conclusions Update, Conclusions, and Recommendations of “Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis” . . . . . . . . . 287 Erina Iwasaki, Abdelazim M. Negm, and Salwa F. Elbeih

Introduction

Introduction to “Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis” Abdelazim M. Negm , El-Sayed E. Omran, Erina Iwasaki, and Salwa F. Elbeih

Abstract The current chapter presents the main technical elements of the chapters presented in the book “Sustainable Water Solutions in the Western Desert, Egypt” to introduce the chapters to the audiences. It contains information on the following topics covered in the book; activities and culture in the desert and their oases, geological and geomorphological aspects of Dakhla Oasis as a typical example. Also, soil conditions, land use, climatic and meteorological factors, groundwater availability, usage and its management, irrigation management, water logging detection and controlling issues. Keywords Sustainability · Dakhla Oasis · New Valley · Environment · Remote Sensing · Egypt · Agriculture · Water resources · Climate change · Wells · History

A. M. Negm (B) Water and Water Structures Engineering Department, Faculty of Engineering, Zagazig University, Zagazig 44519, Egypt e-mail: [email protected] E.-S. E. Omran Soil and Water Department, Faculty of Agriculture, Suez Canal University, Ismailia 41522, Egypt Institute of African Research and Studies and Nile Basin Countries, Aswan University, Aswan, Egypt E.-S. E. Omran e-mail: [email protected]; [email protected] E. Iwasaki Faculty of Foreign Studies, Sophia University, Tokyo, Japan e-mail: [email protected] S. F. Elbeih Engineering Applications and Water Division, National Authority for Remote Sensing and Space Sciences (NARSS), Cairo, Egypt e-mail: [email protected]; [email protected] © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_1

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1 Background Because the landmass of Egypt consists of 96% desert, 98% of the population resides on only about 5% of the landmass, mostly on the land along the Nile River and in the Nile Delta. Egypt’s vast areas are deserts have promising natural resources, including solar radiation and agricultural activities (Fig. 1). The water crisis further calls for particular attention as the Nile River presently supplies 97% of Egypt’s freshwater resources. Despite these challenges facing Egypt, there is an urgent need to enhance water consumption capacity and increase existing water supplies with more sustainable alternatives. There are numerous suggested approaches for improving efficiency. These approaches include treatment/reuse of wastewater and management of groundwater resources (Abdel-Shafy and Mansour 2013). On the one hand, although water resources in the desert are limited to the groundwater, it has a lot of other natural and cultural resources as well, given its history dating back to the Antiquity era (Vivian 2000; Sampsell 2003). In the book edited by Elkhouly and Negm (2021), Development and Management of the Natural Resources in the Egyptian Deserts are discussed, while in the book “Groundwater in Egypt’s Deserts” edited by Negm and Elkhouly (2021), the groundwater availability and sustainability are discussed. In the social science field, there are studies done on the desert land such as by Barnes (2014) on the farmer’s everyday politics in Fayoum, or the desert urban planning by Sims (2014). In this book, the focus is on one typical oasis in the Western Desert, namely, Dakhla Oasis. It consists of 15 chapters of different approaches in natural and social sciences, and includes introduction and the conclusions chapter. In Chap. 2 titled “The Egyptian Western Desert: Water, Agriculture and the Culture of Oases Communities”, the authors provide a background of the Western Desert. It starts with a historical background, followed by

Fig. 1 Egypt map showing that Egypt is formed of a narrow green valley around the Nile River and vast areas are deserts with promising natural resources including solar radiation and agricultural activities

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population culture and migration. The economic activities which include agriculture, mining and pottery are discussed. Also, women’s life and their activities are presented. The tourism activities are highlighted and the environmental problems of the oasis are presented. On the other hand, the Western Desert oases are fully dependent on the Nubian Sandstone Aquifer as their only source of water. Given this, water, particularly irrigation water for agriculture, is used extremely inefficiently (see Chap. 14 titled “Detecting and Controlling the Waterlogging in Dakhla Basin”. Groundwater is one of Western Desert and Egypt’s most important water resources. Groundwater quality depends on two main factors, namely the water source and the form of bearing rocks. There are also important factors in the movement and flow of water from one point to another. Renewable groundwater’s major feeding sources are rainwater drainage, irrigation water, treated sanitary drainage water, and treated industrial wastewater. The quality of groundwater is therefore greatly affected by both surface activities and the amount of water that fills underground reservoirs (Elnashar 2014). Water quality monitoring and identification of factors influencing this quality are very crucial baselines for achieving effective water resources management and sustainable development (Alexakis and Tsakiris 2010). Leaching and oxidation of weathered rock is the major influence on groundwater quality. In addition, these hydrochemical processes help to gain insight into the contributions of rock-water interactions to the performance of groundwater (El-Sayed et al. 2012). El-Zeiny and Elbeih (2019) studied the Water Quality Index (WQI) for Dakhla Oasis. The study indicated that nearly 95% of the Dakhla Oasis wells studied are safe for drinking using Egyptian and WHO standards. In addition, most wells are suitable for irrigation taking into consideration the international recommendations for irrigation. Most aquifers usually consist of either unconsolidated or consolidated granular material (sand and gravel) or fissured and karstified calcareous material. Such aquifers are infinite or semi-confined. In the Nile River region, there are numerous groundwater aquifers of different significance for exploitation. They range from lowlying local aquifers, recharged by rainfall, to deep aquifers containing large-scale non-replaceable reserves (Elnashar 2014; Abdel Moneim et al. 2014). The yield of aquifers varies depending on their composition. Three types of aquifers are available: broken-bedrock, weathered-mantle and fluvial aquifers. Fractured bedrock is the highest yielding aquifers, the weathered aquifer and the fractured double-layered aquifer (Taylor and Howard 2000). Poorly weathered aquifers, also ideal for livestock, are capable of producing groundwater. Extreme weathering triggers the deposition of residual accumulations of many secondary minerals, uranium and heavy metals (Phillips and Watson 2015). Aquifers located adjacent to large surface water courses are alluvial and fluvial. These aquifers are found at relatively low depths, as in the Nile aquifer (NWRP 2005).

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2 Themes of the Book Therefore, the book intends to address in more detail the following main themes: – Geology, Geomorphology, Archaeology and Climate – Land use, Soil and Cultivation – Hydrology and Water

3 Chapters’ Summary The next subsections present the main technical elements of each chapter under its related theme.

3.1 Geology, Geomorphology, Archaeology and Climate Chapters 3–6 cover this theme. Chapter 3 is titled “Geology of Dakhla Oasis, Western Desert, Egypt”. It presents a detailed review of the geological features of Dakhla Oasis. Some of these features include the exposed Upper Cretaceous—Lower Eocene rock units in the area extending between Teneida and Abu Minqar, is divided into Taref, Quseir Formations of the Nubian Sandstone Group (Pre-Maestrichtian age), the Duwi Formation (Lower Maestrichtian), the Dakhla Formation (MaestrichtianPaleocene) subdivided into Mawhoob, Beris Mudstone and Kharga Shale Members. In Qur El-Malik area, the Kharga Shale Member laterally changed in facies to Qur ElMalik Sandstone Member. The succession of the Tarwan Formation (Upper Danian— Landenian age) represents the Nile Valley facies. The Garra Arbein facies was represented by the Kurkur and Gara Formations east of Dakhla Basin at Teneida area. The Quaternary deposits are related to Aeolian, fluviatile and lacustrine sediments interrupted by wet and dry spring phases. Generally, the area is characterized by simple structural elements and has been untouched by strong tectonic forces. The “Geomorphology of Dakhla Depression” is presented in Chap. 4. This chapter sheds some light on the Dakhla depression geomorphological units and sub-units. The chapter connects the study area natural system to the wider surrounding area of the southwestern Desert of Egypt. In addition, this chapter reviews the study area’s geographic location to consider the connectivity of the Dakhla Oasis among other depressions in Egypt’s Western Desert. The analysis of geological data gives a basic knowledge to analysis landforms evolution in the area under consideration. Reviewing the southwestern portion of Egypt’s regional paleo-geomorphology reveals that Dakhla is highly influenced by regional geomorpholgy, especially with the interrelationships with the plateau of Gilf El-Kebir. This chapter’s main body is devoted to the description of the main geomorphological units. In addition to various types of sand dunes, these units are plateau and escarpment; depression

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floor; springs and wells. The chapter also provides some important conclusions and recommendations on Dakhla’s environmental sustainability. Chapter 5 with the title “Archaeological and Eco-tourism areas in Dakhla Oasis Western Desert, Egypt” explains and discusses the archaeological sites in Dakhla Oasis region. Such sites include evidence of the alternating periods of wet and dry climate in the formation of Oasis landscapes, ancient civilizations, and changes in climate. It emphasizes the nature of the relationship between water and life in a spring-fed oasis with groundwater as in the region of Deir El-Hagar and surface water as in the Gilf El-Kebir area’s active wadis and lakes. Tourism is still small in Dakhla Oasis compared to the rest of Egypt, which has helped to preserve its heritage. Dakhla Oasis is rich with many archaeological sites from prehistoric to recent times, landscape and natural resources. A special attention should be addressed for the development of these resources for ecotourism and desert safari. It contains a vast remote area which is not accessible and needs a good management plan for the conservation and protection of these resources for future generations and researchers. Following to the archaeological chapter, come the chapter on “Climate features of Dakhla Oasis” to explain the recent climatic and meteorological conditions in Dakhla Oasis which are related to the human activities and environmental conditions. It explains the climatic characteristics in Dakhla Oasis and the climatic variations between Dakhla and Kharga Oases using synoptic meteorological data from 2007 to 2016 in order to understand the variability of annual precipitation and the level of oasis aridity. Also, other meteorological parameters and its relationships with water demand of the crops in the oasis are analyzed and the results are presented.

3.2 Land Use, Soil and Cultivation The chapters from 7 to 10 explain the issues related to sand dunes in the oasis, soil conditions, land use, groundwater, and cultivation. Chapter 7 is titled “Aeolian Sand Transport Potential and Its Environmental Impact in Dakhla Oasis, Egypt”. It describes the movement rate of sand dunes in the Dakhla Oasis and their impact on the cultivated lands and the relationship between wind speed and direction with sand dune distribution and movement as well as the connectivity between the oasis and the African continent. The African continent comprises of a massive, shallow depressed plateau. This has around one third of the arid lands of the world, mainly characterized by the Sahara, Kalahari and Namib deserts. Dunes are the arid land of the most unique aeolian characteristic of Africa. In African deserts, they comprise about one-fifth of the shallow depressions being broad. The most common forms of dunes in Africa are linear and crescent dunes however the most popular are linear dunes. In Egypt, sand dunes occupy more than 17% of the surface area of the country. The Great Sand Sea is about 80% of Egypt’s dunes. There are two major categories of dunes characterizing the Dakhla Oasis sand dunes: crescent and linear. The most common types are the crescentic compound dunes (barchanoid ridges). Linear dunes mainly take place in the southern portion of the eastern dune belt. Dakhla dunes

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are continually moving to the South, damaging streets, houses, agricultural areas, irrigated canals, and artesian wells. Movements of the Dakhla dunes are largely influenced by the spatial variation of the wind system, wind velocity and distance from the northern plateau. The crescentic dune movement rate at Dakhla ranges from 0.5 to 14 m/yr with a mean of 5.8 m/yr. Southwest of Mut the southern severity of linear dunes ranges from a few meters to 15 m/yr with a mean of 7.5 m/yr. The annual growth rate of the dune is 25 cm/yr for width and 37 cm/yr for length. Monthly sand roses reveal that the drift potential (DP) varies widely based on the effective wind speed. The estimated yearly DP of Dakhla is 787 vector units (VU) while that of Farafra is 1882 VU. The peak DP is shown in the spring season (African.cu.edu.eg). Chapter 8 is devoted to discuss the “Soil conditions of Dakhla Oasis, Western Desert, Egypt” to integrate the picture presented in Chap. 7. The soil survey, land identification and land evaluation (soil conditions) data in Dakhla Oasis is very useful in identifying land use opportunities and risks and can help direct government policy towards efficient and productive use of soil and soil resources. Egypt now has the lowest fertile land per capita of any country in Africa. With a steadily growing population and high food crop imports, Egypt will need to sustainably control its arable land and develop new desert land. Food shortages and ongoing loss of agricultural land (e.g. urban encroachment on agricultural land in Nile valley and Delta) are most important issues for Egyptian Government. The government of Egypt implements policies loading to self-sufficiency in food production, such as reclamation of 1.5 million feddans (1 feddan = 1.03784 acre, 1 feddan = 4200 sq.m and 1 acre = 4046.86 sq.m) in the Egyptian desert and maximizing production of the existing agricultural land. Such regular incremental growth requires considerable attention to protect the limited land resources in order to increase Egypt’s agricultural productivity per unit area and maximize reclaimed agricultural land. Dakhla Oasis represents one of the high priority regions for future agriculture development in Egypt. It is one of the major depressions in the Western Desert of Egypt for land reclamation based on availability of land and water resources. Chapter 8, therefore, aimed to evaluate land resources in Dakhla Oasis using remote sensing and GIS for different crop requirements. Following the above two chapters, Chapter 9 comes with the title “Remote sensing and GIS for Land use/Land Cover change detection in Dakhla Oasis” to discuss the matter of land use/land cover change in Dakhla Oasis from 1988 to 2018 in two periods using remote sensing and GIS techniques. Various kinds of multispectral satellite sensors were used for tracking and mapping the land use land cover and its changes that occurred from 1988 to 2018. Three satellite images were used in this chapter, including Landsat TM (1988), Landsat TM (2003), and Sentinel 2 (2018). Land use/land cover map was produced based on the supervised classification method (SVM) for multispectral satellite image. The area of study was categorized into five main classes; land-built, agricultural land, sand dunes, desert, and water bodies. Changes that occurred in the main classes of land use land cover in the study area were detected over the last thirty years from 1988 to 2018. It was divided into two periods; each one is about fifteen years. The

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first period is from 1988 to 2003, and the second is from 2003 to 2018. The overall changes in the main land use/land cover (LULC) classes during the whole period of the study (1988–2018) are discussed. The increase of the total area of built-up land, agricultural land, and water bodies was amounted and presented in the chapter. To integrate the picture of this theme, Chap. 10 with the title “Crop diversification and its efficiency in Rashda Village, Dakhla Oasis” is included to analyze the technical and scale efficiency of farms focusing on crop production in Rashda Village (Dakhla Oasis), using cross section data of agricultural households collected from the household survey in Rashda in 2009. The authors analyze farmers’ diversification strategies focusing on crop production in Rashda village in Dakhla Oasis. Technical and scale efficiency of farms in Rashda Village is investigated by using DEA (Data Envelopment Analysis) approach. Results suggest that the estimated efficiency scores of farm households in Rashda are generally low, with most farms showing less than 40% of technical efficiency. However, estimated results also suggest that the output level with the current level of inputs can be increased by 82.5%, 79.8% under the constant returns to scale (CRS), variable return to scale (VRS) specifications. About 24.6% of farms can increase their production and productivity through increasing their inputs, while 24.1% can improve their productivity by reducing their inputs. While the crop diversification does not contribute to improve efficiency, the expansion of cultivation of watersaving crops such as dates is a positive factor for improving efficiency. Human capital accumulation, increase experience and intensification of family labor use would contribute to improve technical efficiency.

3.3 Hydrology and Water Because agriculture and other forms of life without water are not feasible, this theme focuses on water issues in the Dakhla Oasis. Chapter 11 is titled “Hydrologeological and Hydrological Conditions of Dakhla Oasis”. This chapter reviews previous investigations concerning hydrogeologic characteristics of the deep groundwater aquifers in Dakhla Oasis and distribution of drainage networks in the Depression. Also, it assesses the hydrogeologic characteristics of the deep groundwater aquifers in the Dakhla basin. In addition, a review on the irrigation system and drainage ponds are highlighted. The aquifer consists of sandstone, shale and clay alternating beds. The Nubian Sandstone basin is tectonically affected by regional faults and is divided into different sub-basins. Drainage ponds are formed in the Dakhla Oasis due to agricultural operations where the agricultural ecosystem produces and consumes water. It is surprising that sustainable development and agricultural progress in the Dakhla Oasis have been lagging behind expectations. It poses a challenge to the drainage network infrastructures. In many areas, drainage systems do not work effectively, creating problems with water pollution, soil degradation, and salinity. It is well known that the main source of water in Dakhla Oasis is groundwater. Therefore Chap. 12 describes the “History of Wells in Rashda” as a typical village

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in Dakhla Oasis. This chapter explores the technology-human society relationship, concentrating on the advancement of well-drilling technology, using Rashda Village as a case study in Dakhla Oasis. The livelihood in an oasis depends on groundwater drawn from wells. Hence, the oasis has a well-centered society determined by the nature of the wells. In the study village in Dakhla Oasis, wells are classified into five types: government wells (bir hukumi), local wells (bir ahli), investment wells (bir istithmari), surface springs (‘ain sathi), and Roman springs (‘ain rumani). Their names imply a distinction between springs (‘ain) and wells (bir). Different types of wells have different forms of livelihoods. By focusing on the history of well drilling in the study village, this chapter attempts to understand how technological development has changed the fundamental problem of the relationship between humans and water. Since the late 1950s, the drastic change in the human relationship with groundwater has taken place with the development of modern technology. The deep-well drilling machines and pumping technologies have enabled the vertical and horizontal extraction of the groundwater. The technology of water discharge enabled the discharge of a large amount of groundwater and the ability to overcome water deficiency, whose consequence since then was the lowering of the groundwater level. Knowing the limitations of the water resources in the desert and in Dakhla Oasis as well, Chap. 13 comes with the title “Development of land use and groundwater in Rashda village (Dakhla Oasis), 1960s-2018” to identify the land expansion dynamics and their primary drivers in Rashda village in Dakhla Oasis as a typical example. The authors analyze the changes in land use and the wells development in the village for the period between 1968 and 2018. Land uses were identified using 1968 Corona images and 1988 and 2003 Landsat images and 2018 Sentinel-2 images. Groundwater data were collected from field survey and South Western Desert groundwater central laboratory. Results indicated that the area occupied by irrigation agriculture has accelerated since 1968, and its area doubled over the past 50 years. During that period, there was a simultaneous increase in total population and constructed wells during implementation of the New Valley Project. Thus, human migration and national development are identified as potential drivers of land expansion. In Chap. 11, the authors stated that waterlogging problems were observed in Dakhla Oasis. Therefore, Chap. 14 with the title “Detecting and Controlling the Water logging in Dakhla Basin” discusses the waterlogging in Dakhla Basin (Dakhla Oasis, Kharga Oasis, and Farafa Oasis). The ability of the various oases for the issue of waterlogging and salinity is different depending on the hydrological, socioeconomic and political conditions. Therefore, Chap. 14 tries to detect waterlogging in three basins in the desert, namely, Dakhla Oasis, Kharga Oasis, and Farafa Oasis. First, Dakhla Oasis is a relatively large oasis 350 km away from the Nile River. Aquifer extraction has already some environmental impacts. If the current rate of extraction were raised, the economic level of 65 meters below ground level would still not be reached. The groundwater quality in this oasis is generally good and this means that the agricultural area in this oasis could be increased. Second, Kharga Oasis is located 140 km east of the Dakhla Oasis. The quality of the water is good but the extraction is already so high that it has repercussions and the water level has deteriorated as a result. The third, Farafa Oasis is located 627 km from Cairo and has some natural

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wells and 140 active wells, and there are good opportunities to expand the agricultural areas east of Farafra, but it has resulted in environmental dangers and diminishing groundwater level due to poor placement of wells. In Dakhla Basin, five major factors responsible for the issue of waterlogging and salinity are identified. Hardpans are the main causes of waterlogging and salinity problems. A second cause is the lack of drainage. The third cause is irrigation systems. Even the depletion of groundwater quality is the result of over-irrigation. Last but not least, over pumping groundwater is a major contributor to the development of waterlogging in the Dakhla basin. In Chap. 15 titled “Hydrogeophysical investigations using DC Resistivity survey to assess the Water potentialities of the Shallow Aquifer Zone in East of Dakhla Oasis, Egypt”, the authors present an integrative approach to illustrate the aquifer characterization and groundwater potentiality in the upper zone of NSAS based on the geophysical and geologic information from the available data of 16 boreholes (Gamma ray and resistivity logs). The finding of this research could help decision-makers in the Dakhla region to continually improve groundwater quality. The Nubian Sandstone Aquifer System (NSAS) is remains one of the largest’s largest, potable groundwater basins.The main objective of the present work was to evaluate the groundwater potentialities and their extension by an integrated application of DC resistivity sounding survey, lithologic information from boreholes, and the TDS data in the upper zone of Nubian Sandstone Aquifer System (NSAS). Moreover, locating the proper sites for drilling new productive wells must satisfy the increasing needs of water in such an arid area. The results of this study can help decision makers to maintain and improve groundwater quality. The Nubian Sandstone Aquifer System (NSAS) is considered to be one of the most significant and potable groundwater basins in the world. The book ends with the 16th chapter with conclusions and recommendations. The update of the literature is made in the conclusion chapter to cover some of the interesting topics related to the book’s themes. Acknowledgements The authors of this chapter would like to acknowledge the authors of the chapters for their efforts during the different phases of the book including their inputs into this chapter. Also, Abdelazim Negm acknowledges the partial support of the Science, Technology and Innovative Fund Association (STIFA) of Egypt in the framework of the grant no. 30771 via the Newton-Mosharafa funding scheme, call no. 4.

References Abdel Moneim AA, Zaki S, Diab M (2014) Groundwater conditions and the geoenvironmental impacts of the recent development in the south eastern part of the Western Desert of Egypt. J Water Resour Prot 6:381–401 Abdel-Shafy HI, Mansour MS (2013) Overview on water reuse in Egypt: present and future. Sustainable Sanitation Practice 14:17–25

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Abo El-Sayed MH, El-Fadl MM, Shawky HA (2012) Impact of hydrochemical processes on groundwater quality, Wadi Feiran, South Sinai, Egypt. Aust J Basic & Appl Sci 6:638–654 Alexakis D, Tsakiris G (2010) Drought impacts on karstic spring annual water potential. Application on Almyros (Heraklion Crete) brackish spring. Desalination Water Treat 16:1–9. https://doi.org/ 10.5004/dwt.2010.1065 Barnes J (2014) Cultivating the Nile. The everyday politics of water in Egypt. Duke University Press Elkhouly A, Negm AM (eds.) (2021) Development and management of agricultural and natural resources of Egyptian deserts. In Springer Water Series. Springer (under production) Elnashar WY (2014) Groundwater management in Egypt. IOSR-J.M.C.E. 11:69–78 El-Zeiny AM, Elbeih SF (2019) GIS-based evaluation of groundwater quality and suitability in Dakhla oasis, Egypt. Earth Syst Environ 3:507–523 Negm AM, Elkhouly A (eds.) (2021) Groundwater in Egypt’s deserts. In Springer Water Series. Springer (under production) NWRP (2005) National Water Resources Plan for Egypt (NWRP) up to 2017: Policy Report: Water for the future, planning sector, Ministry of Water Resources and Irrigation, Cairo, Egypt, pp 211, 223 Phillips DH, Watson DB (2015) Distribution of uranium and thorium in dolomitic gravel fill and shale saprolite. J Hazard Mater 285:474–482 Sampsell BM (2003) The geology of Egypt. A traveller’s handbook. American University in Cairo Press Sims D (2014) Egypt’s desert dreams: development or disaster? American University in Cairo Press Taylor R, Howard K (2000) A tectono-geomorphic model of the hydrogeology of deeply weathered crystalline rock: evidence from Uganda. Hydrogeology J 8:279–294 Vivian C (2000) The Western Desert of Egypt. An explorer’s handbook. American University in Cairo Press

The Egyptian Western Desert: Water, Agriculture and Culture of Oasis Communities Soher Hussen Ibrahem Mohamed

Abstract In this chapter, the author will show the cases of oasis communities in the Western Desert in Egypt. The importance of these communities has risen, especially after the expansion of construction on agricultural lands in the Delta region, thereby reducing the size of its agricultural areas. This, in turn, meant resorting to shifting agricultural activities to the Western Desert. The author has done a series of studies and social and anthropological research on these areas that are economically promising , especially with regard to agricultural and tourism activities. Keywords Local communities characteristics · Dakhla–Kharga · Oases of Western Desert · Oasis culture

1 Introduction This chapter shows the cases of oasis communities in the Western Desert in Egypt. These oasis communities include, Siwa Oasis about 300 km south from Matruh Governorate, Bahariya Oasis about 365 km away from Giza Governorate. New Valley Governorate contains the rest of the Western Desert Oases, including Farafra, Dakhla, Kharga, and Baris Oases. The Western Desert Oases occupy an area of more than two-thirds of the total area of the desert, which is 68% of the Egyptian desert. Figure 1 shows these oases. The importance of these communities has risen especially after the expansion of construction on agricultural land in the Delta region, consequently, reducing the size of its agricultural areas. This, in turn, meant shifting agricultural activities to the Western Desert. In addition, there is a limited amount of social and anthropological studies and research conducted on these promising areas especially in terms of agriculture and tourism activities. Without a doubt, the anthropological and social research and studies on desert communities are of great scientific value. Such scientific resources have a vital role in S. H. I. Mohamed (B) Sociology and Anthropology Department, Faculty of Arts, Helwan University, Helwan, Egypt © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_2

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Fig. 1 Location of different oases in the Western Desert of Egypt

increasing the awareness of rural people towards some threats. These kinds of threats might lead to the demise and extinction of their rural lifestyle which distinguishes rural communities from any other. The most important feature of such threats is that they are intangible and occur with the natural flow of the development of the rural community. Only social and anthropological research can detect and analyze these kinds of threats to avoid or at least mitigate their impacts on the culture of lifestyle in desert communities (Abu Zaid 1991).

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2 Historical Background of the Oasis Community in the Western Desert The oases in the Western Desert have a significant historical background since the ancient Egyptian civilization. The best evidence of this is a large number of monuments in the oases, which ranged from residential cities, graveyards, temples and others throughout the Persian, Greek, Roman, Coptic and Islamic eras. Oases, since ancient times, are considered as the areas linked to the civilization of the Nile Valley and other civilizations located in the west, North Africa or the Western Desert and western Sudan. The oases inhabitants in those areas have left drawings on rocks such as in Gabal Tair in Darb Ghobary (Ghubari) between Kharga and Dakhla Oases close to Kharga (Fig. 2). Further, the ancient Egyptians were concerned with securing the caravan routes to the oases. Oases were also affected by the periods of weakness and strength of the kings of ancient Egypt. Many Egyptian oases suffered from invasion and oppression. So came the army of Qambiz, who destroyed their temples and burned their statues and his successor King Darius, who differed from his father. He turned his attention to the people of the oases to settle them. He set up two temples for Amun, one in Siwa (Umm Ubaida) and the other in the city of Kharga (Temple of Hibis) and rebuild the temples that were destroyed. Hibis means the city of the plow, or the city that is cultivated. This indicates that agriculture is of great importance (Abdel-Hamid 1971).

Fig. 2 Dakhla and Kharga Oases, and Darb Ghobary

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Kharga Oasis (Fig. 1) known as Tiba was referred in Egyptian texts by the name of Hebt, which means “plow”. The oasis was connected to Nile Valley in a variety of ways from Abydos Luxor, Esna and going through Darb Al-Arbain linking Assiut with Darfur in Sudan (Nureddin 2005). The oasis, consequently, has many archaeological areas. The oasis was also a place of storage of grain and grapes, which became the primary source for the finest wines to Rome. Farafra Oasis (Fig. 1) is known as “the belly of the cow” due to the presence of a large quantity of groundwater, many of which appear on the surface of the earth in the winter-time and therefore, resulted in many farmlands on flat areas. There is also Dakhla Oasis, meaning “entrance”, located in the center of the Western Desert. Bahariya Oasis (Fig. 1) has a population is of about 32,000. Bahariya Oasis is divided into several villages such as Mandesha, Al-Zabuw, Al-Qasr, Al-Hara, AlQabala, Al-Aguz, Al-Hayz, in addition to Bawiti city. Bahariya Oasis is characterized by the diversity of the monuments of the Coptic, Roman and Pharaonic eras, and has many ruins of church and olive groves from the Roman era. The oasis has also the tombs its discovered by the world famous archaeologist Zahi Hawass in the region of Umm al-Lafah, meaning the area full of snakes. Nearly three thousand golden mummies are found there. Siwa Oasis (Fig. 1) has a population of up to 25,000 inhabitant distributed within the residential cordon of 36 km. The oasis is about 18 m below mean sea level and includes a set of small populated oases due to the bad-land (agriculturally unproductive land) and the scarcity of groundwater wells. Siwa Oasis is the only oasis located near to the Mediterranean Sea. The oasis was referred to as Sepah in a report of the year 1664, and Al-Makrizi emphasized this name in his book in 1792. However, the ancient name was “the land of date palm trees” (Demeiri 2005). It was home to about 600 people of barbarians known as Siwa whose language was similar to the language of Zenata. The Siwan tribes composed of 8 sub-tribes were formed by the mixture and integration of the Yemeni, the ancient Egyptians and Berbers. They came from the east and west of the North Africa distributed between Morocco, Algeria and Libya. Siwan people built their homes with a substance called kurshif which is saturated mud with salt, like cement. Many old houses were built on top of each other to achieve heights over the mountainin in the center of the city to achieve the cohesion and solidarity between the family members and to achieve safety from threats of raids and invasion from the west.

3 Population Each oasis has its tradition and has its dialect that differs from others. There is also a sense of ethnicity and distinction between the villages of the oasis. Some villages, lost their specifity when they received the strangers from the villages of Delta Lower Egypt or Upper Egypt who came to work in agriculture or trade.

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This is unlike Siwa Oasis, which is characterized by its origins, as we mentioned before. The people speak the Amazigh language given the ancient Syllabi integration. Although young people now speak Arabic language and some foreign languages after the spread of tourism, they still retain the ancient inherited language of Amazigh. There are clear differences between the residents of Kharga Oasis and Dakhla Oasis, for example, in terms of physical features. The population of Kharga Oasis is characterized by its dark skin and hair, brown eyes, unlike the residents of Dakhla who are characterized by light skin, blond hair and light-colored eyes. This mainly dates back to the historical eras (Greek and Roman) and their integration with the local people during the occupation where marriage was wide-spread among them. The same happened in two villages in Bahariya Oasis (Mendisha and Al-Qasr).

4 Migration Egypt’s oases have changed since the 1970s. As a strategy to develop the western sideline of defense for Egypt, the government opened the New Valley equivalent to the Nile Valley. From here the government has drilled numerous wells and planned to reclaim a million and a half acres to provide job opportunities for young people. Also, it aims at providing agricultural crops rather than importing them. It is worth mentioning that the new wave of investments is made by Arab investors. A well-known system in the oases is called Mugaala. It organizes the relations between the landowner and the person who farms the land. It is still a common custom in the oases despite the immigration of the people from Delta. It can be said that internal migration from the oases to Cairo, capital of Egypt, is essentially a migration of poverty and drought to search for jobs. This was evident from the early twentieth century until the mid-fifties. When Gamal Abdel Nasser launched the development of deserts through the Desert Reconstruction Authority, many oases people returned to their lands. Now, new forms of internal migration have emerged from the delta areas to the oases to work on agriculture or for other occupations. The migration made some of the oases remarkably populous, increasing other economic activities that have not existed before. The people of Siwa did not turn to internal migration over time believing that they are special in ethnicity. Moreover, when young people thought later to work outside their land, they immigrated to Jaghbub Oasis in Libya because it is located near to Siwa, about 120 km away, and quite close to Siwan in terms of customs and traditions. Many of Siwa’s young people work in this oasis in the oil fields, but they do not stay for more than two years because they do not prefer to stay away from the family as they are closely linked to their parents. Nonetheless, they do not tend to migrate to Morocco despite the similarity in language. Jaghbub Oasis relies on Siwa Oasis who provide the agricultural crops to them every season. This was revealed during the Libyan revolution in 2011, unifying

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the efforts of all residents of Siwa Oasis and Matruh Governorate to send all the food they needed, given the political events that exposed during the Libyan revolution.

5 Economic Activities in Oases 5.1 Agriculture Winter and summer seasons differ in the level of groundwater used for irrigation as a result of evaporation that occurs during irrigation. Winter crops are such as wheat, bean, tomatoes and potatoes and summer crops are such as rice, corn, dates, citrus, and mango. The economic activity in the oasis community is based on agriculture and the strength of date palm cultivation. Therefore, multiple factories focus on preserving and exporting dates, such as the palm factory in the village of Al-Zabu with an area of 12 acres at the cost of 2 million Egyptian pounds and which produces 5 tons per day. Another important product is apricot, which is usually dried in farmyard ovens for preservation and storage. Apricot production has a capacity of 10 million Egyptian pounds per season. There is a date factory in a village called Mendisha. The oasis also depends on the planting and cultivation of olives, oranges and tangerines. Olive cultivation is also the main activity there, as well as apiaries of natural honey bee which uniquely characterizes this oasis from the rest of the others. Moreover, there is a growing proportion of the citrus cultivation precisely because of the high rates of salinity in irrigation water. All the oases depend on the livestock and its variety (camels, sheep, goats), which provide safe meat and reduces imported one. Bahariya Oasis is distinguished by its kind Barqi, because it is from the city of Barqa in Libya. It has a particular taste and differs from those in the Delta. Also, a large proportion of hybrid cows have been adapted to desert’s dry climate. There are projects to support raising animal for industrial insemination and local breeds and genetic improvement to increase production efficiency. There are more than 60 thousand heads of cows and the same number of goats and about 100 thousand camels. There are also projects for oasis raising chickens.

5.2 Mining The people in the oases need factories to extract salt from the bottom of lakes. This is especially the case in Siwa Oasis, where the largest salt mines in the area of Abu Shroff was discovered. Such lakes result in an increase in the level of salt

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and salination of agricultural lands. Thereby, it affects the production of agricultural crops and new business opportunities for all the young people.

5.3 Pottery The population there are also excellent in the use of the environmental elements, such as the mud soil in the houseware industry (pottery industry). Clay pot is used in cooking and storage of ghee after milking sheeps or cows. It is also used in decorative objects inside and outside the house. Also, it is common to drawings on the walls of houses are popular among the oasis population. It reflects the various events in family life, namely, as the ancient Egyptian did on the walls of temples. The importance of pottery is also observed in the drinking water conservation. The water is placed in Mazira (meaning water jar) where the pores found in pottery works on water purification from impurities and helps to protect the health of the rural community. The abandonance of such environmental industry exposes the oasis population to health and physical risks. These pots are still used in everyday life. For example, we find Mahlaba (milking bowl) in which milk is placed. Manfaha (meaning rennet) is used in the fermentation of milk, and Baklaya or Bulas (big jar with small opening from the top while it is wider at the bottom) is used in preserving the old cheese, which is one of the most important elements of food saved for rural people in general in the Egyptian countryside. The matter is different for the usage of ovens called Tabuna inside the houses, which was recently replaced to electric oven. This has led to an increase in the agricultural residues that were used by women to warm-up the oven. These residues are rice straw, animal and bird residues that contribute to thermal energy. This also led to the spread of predatory animals that threaten the environment, in addition to the environmental pollution resulting from these wastes. One of the natural materials extracted from local environmental sources in the ground is called Gleez. It is a color material of high-quality to paint pottery tools instead of importing them from abroad, which costs the government a lot of hard currency. This is reflected in the price of the product. The material used in the manufacturing of roofs is called Armid. It is strong and durable material, adaptive to desert climatic conditions.

6 Women’s Life and Activities In the oases, elder women are still keen to keep the uniforms of the oases called Kitany. In some rural villages, they make them by their own hands. The basic uniform is black and decorated with strings colored in red, yellow and blue at the front of the chest till the bottom. The uniforms are generally wide from the bottom, to conceal the bottom parts of woman’s body.

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Uniforms are also embroidered by coins. This is due to the development of an important rule in the value structure of the oasis, obliging men to sit on the terraces next to the houses when women walk from place to place. Women consider black color to represent dignity and modesty, and the color white to indicate joy and delight. Together, these two colors represent the basis of the old folklore oasis for the people. The red color is used for therapeutic purposes which are also part of the belief of rural areas across Egypt. Red color helps the healing process for children when they are sick with measles. However, oasis women wear other colors inside their houses so as not to be seen by strangers. Interestingly, young brides make their own wedding dresses as well as family members’ clothes. It is usually quite a difficult process. It could take up to nearly three years. The bridal dress usually features popular designs inspired by the environment and in the daily trips girls enjoy when they roam the desert. The dress also includes graphics and natural colors all made with simple tools (scissors, needle, strings) on fabric that are brought by traders from Al-Azhar area in Cairo. Rural and oasis women contribute to their household and family expenditure through designing and making clothes and garments manually with very high quality. Women give the products to their husbands to distribute and sell them among the various markets in the city center as well as to foreigners. This is particularly the case with the rise in tourist activity in the late 1980s. Women also have contributed to the pottery industry since ancient times during the Pharaonic era in Egypt. The pottery is used every day inside the house for cooking and storing necessary foods such as pickled olives, Laranj (a kind of citrus) and cheese. These foods are an important food for all desert dwellers because it is linked to the sunstroke diseases that may affect some residents while working in Hattaya. Hattaya is a family farm in which all members of the family work. Also, women use the palm leaves (Jerid) to make Suwasil and Margun (a box or container made from the frondes of palm tree) which are used in storing and preserving dates. The latter is considered to be the main crop throughout the year. Women make headwear which men wear over their head during their work in the fields and agriculture. Women also make Galak (a kind of pot made from palm fronds) to put agricultural products when they return home. They further make Bursh (a kind of mat) which is one of the furnishing placed on the floor to replace carpets. Women embroider Bursh with bright colors and beautiful shapes. In the past, every female had to make and design Bursh before her marriage. The female’s relatives assisted her if she did not have enough time until the wedding. Early marriage is the norm for girls in the oasis communities, and usually, marriage takes place among relatives. The old Egyptian society did not allow the female to exercise her rightful activity in her environment and to conduct some civil and religious affairs in public life. Recently, women in the oases gained new civic and religious cultures that enable them to participate some activities in public that are suitable to her age, position, and tradition (Saleh 1988).

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Some rural villages in the oases seek to establish factories for pottery. Such factories tend to operate using traditional and primitive ways (cupboard) and are dominated by men. It is because of society’s belief that it is a craft that women can not work on. However, with the complexity of economic life and increase of rural migration from outside the oasis to oasis, there has been an increasing need for women to work. Further, the lack of government jobs has further pushed females to work in manual labor. This has led to a demonstration of the artistic sense of the females in the use of different colors to decorate clay pots. There are a good number of local workshops operated by women in all the oases mainly focusing on handicrafts, including hand-made carpet from sheep’s wool and jelbab (galabiya) wahata (i.e. oasis dresses). Each oasis has its unique model and decoration for its products depending on the surrounding environmental resources for accessories. However, there is a shortage in the number of outlets and marketing opportunities for such crafts and products to market inside and outside Egypt.

7 Impact of Tourism on Agriculture The environment in oases is an important source for the establishment of many types and forms of tourism including: 1. Medical and therapeutic tourism, due to the presence of sulfur springs flowing self-healing of many rheumatic diseases, bone. 2. Safari tourism where visitors roam all the dazzling natural areas, many of which have been deemed globally as natural habitats. Reserves that cannot be entered without permission include the Black Desert wherewith formations of black roses fossilized scattered formed by erosion and erosion form. Also, The White Desert is full of the natural forms that embody some birds (hen, rooster, rabbit), horse and camel, and the Crystal Mountain, the Cave of Wax and Ain Khadra (meaning “green spring”), which is famous internationally as being enchanted in the area of Farafra (Ain Al-Saru and Ain Dalla). Moreover, there are places of magnificience such as Al-Aqabat meaning “obstacles” between Farafra Oasis and Bahariya Oasis, where large rocks that look like tents are scattered, and Sandy Mountain which are the remnants of the Black Desert. There are also Mountains of Al-Dust and Al-Mugharfa, and the English Mountain in the area of Bahariya Oasis. The latter mountain was prepared by the British during the World War II as a center of protection for them from the West. These mountains are located between the villages of Al-Aguz and Mendisha. There is also Qasr Salim area, that has a number of Pharaonic tombs dug in a rocky plateau, and the cemetery of Holy Apis located in Al-Fararji plateau. Moreover, there are many large springs such as Ain (meaning “spring”) Al-Bashmu, Ain Al-Maftala, Bir (meaning “well”) Al-Matar, Bir Sigam, and Bir No. 6. Next to Ain Al-Muftala are Temple of Hercules, and other distinctive monuments in Kharga Oasis (Temple of Dush, Temple of Hibis, etc.) that were formed by erosion factors. There is also

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the Labkha area which is one of the natural attractions. It was discovered recently and is under study now called the monastery of nuns. Siwa Oasis is located in an extremely dry region with a continental climate. Because of hot summer and mild temperature in winter, people prefer to visit it in winter to enjoy sun and a healthy atmosphere. The oasis is famous for treating various bone diseases and has many archaeological sites to visit: Mount Shali, Temple of AlWahaa, Temple of Umm Ubeida, Ain Shams, Umm Al-Sir, Mount Al-Dakrur, Mountain of the Dead, Colored Tombs, etc. Oases thus include many monuments and locations that have witnessed several historic eras, yet many are still unexplored till now. Since ancient times, the people of the desert have set up homes without digging deep in the ground. As a result, many houses are built over the remains of ancient civilizations. This is exhibited by the presence of many statues. The people of oases call them Shukhus (meaning statues) found at the bottom of the old houses as they built new ones. Working in tourism is relatively a new activity and direction for the oases people. It is an activity and livelihood that brought them a lot of money, changed their original lifestyle, and influenced the layout of kinship and social and ethical strong values that were displayed by the farmers’ population of the oases. They have lived a quiet life in the past, and have enjoyed complacent and cooperation among members of the community. Now, many oases communities witness the collapse of such values such as a reduction in the safety of the roads. For example, in the past, during the animal mating and breeding operations, animals were left in the desert in several natural areas with wild plants, such as Al-Mahmiya, Al-Asila, Al-Jahif. After nine months, its owner would go back to pick up the new offspring. This is no longer possible without supervision. This security system has faded due to the spread of outsiders from the Nile Valley north and south to work in the oases or to buy land and invest in agriculture. Also, unemployment among the youth of the Egyptian society in general and the oases in particular led to the emergence of negative values (new unusual values) among themselves. This included many acts of crime such as the sale of land owned by others to new investors. Young people in the oasis prefer to get married to the foreigners to earn financial benefits like having a Safari car to work in the tourism field instead of agricultural, or building modern houses instead of oasis traditional houses. Usually, tourism activities return more profits than working in agricultural activities. Therefore, there is a shift from agricultural to tourism among young people. This phenomenon might affect the future of the agricultural activities in the oases which are not stable and have fewer profits compared to tourism-earned profits. Agriculture is no longer desirable. Date cultivation depends on the sale of date fruit once a year, where profit fluctuates as it is associated with critical climatic conditions. With the rise in prices of daily food, the rural youth now refrain from working in the agricultural activity and resort to everything that generates quick profits.

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8 Problems of Environment Recently, new health issues started to arise which did not exist in the past such as headaches and high blood pressure due to increasing temperatures in the summer and the spreading of a new phenomenon such as air conditioner. The prevalence of these diseases differs from one village to another depending on the different proportions of soluble salts in the water. The higher the iron levels in the water, the more difficult it is to cultivate land as it deposited on top of the soil and increases the proportion of salt in the ground. Some of the oases, though not all, are famous for their good environment for curing many diseases (Siwa, Bahariya, Farafra) using alternative treatments and traditional medicine derived from the inherited experience of the oasis people. This includes burial in the sand or the use of sulfur water. Nonetheless, due to the lack of a holistic developmental strategy and vision for such activities, such natural resources and therapeutic capacities have not been completely exploited. The inhabitants of the oases in Egypt cope with the winds blowing throughout the year in various forms of methods that protect them. The wind carrying soft sand is a threat to their lives, which might destroy their crops and groundwater wells. Therefore, they windbreaks from date palm and tree planting. The inhabitants of the oases called these winds Samum meaning “poison”. The oases are surrounded by the sand dunes with crescent shapes that affect the efforts of community members to create a comfortable environment, as they threaten their farms and houses because they fall in the direction of the wind, which leads people to move their houses toward south every few months. The village of Jinnah in Kharga Oasis is an example. It was surrounded by dunes from north, west and east, so that many houses and groundwater wells were buried. This resulted in a new distribution of the population as the village was divided into two parts, AlGara and Ain Al-Houd. The villagers dug new wells near their houses (Hussein 1975). The village Bulaq serves as a good example showing the impact and implications of the environment on the oasis populations. The village was submerged and covered by crawling sand from north to south. The vertical migration of the dwelling is shared by most of the agglomerations, especially the old ones. Old deserted villages are often used as windbreaks and scavengers and the new dwellings are established at a higher altitude than the wind extensions. An example is the village of Baris, Al-Max AlBahary. These villages became like a high hill or a hill of sand, where a new village established over an old village. Due to the heavy rains in the 1980s, the building materials, kurshif (clay saturated with salt of stiff saline clay), of Orgomy village was highly affected that some walls of the residential buildings and houses were collapsed. As a result, people built new houses at the foot of the mountain, where they used their old valid windows, doors and the roof that was made of palm fronds. All of these environmental factors have made the people of the oases in permanent conflict with the never-ending conditions. This ecological influence extends to

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elements of the social system in the oases. This is reflected in the continuing struggle by the people of the oasis to face the harsh environmental conditions through individual and collective efforts. The idea of solidarity and cohesion among the inhabitants are exhibited by the collective activities such as well drilling and housing construction through cooperation and participation. Accordingly, physical ability and strength are vital and are of a huge value to maintain life. In many cases, oasis populations resort to divine power through prayer, invitations and saints in raising the environmental danger. Perhaps the greatest challenge that the oasis population face is that of the continuous decline in the amount of water, particularly due to their great dependence on groundwater wells for agriculture. The changing chemical composition of water is also an important issue. The rise in the amount and proportion of the dissolved salts affect the health of the population causing some diseases such as thyroid, kidney diseases, and indigestion. Due to increased salt content and water-free iodine, which helps to develop the disease of stupidity.

9 Conclusion The environment involves three dimensions that contribute to its formation (biosphere, social environment, technological environment). Technology is the product of a particular social environment, because social demand on production of goods and services determines the types and uses of technology. There are bitter experiences of the effects of technology that destroy the environment, but it cannot be dispensed with, and transformed into less harmful technology (Khouly 2002). The society, on the other hand, evokes the behavior of its superiors to the law, in the form of values defined as generally acceptable to identify patterns of interpersonal relationships. Alternatively, it is a comprehensive construction where each value represents a component interacting with other values. This leads to the achievement of the function of this pattern, which is to achieve the survival and development of society (Kanani 2012). Hence, the anthropological and social research and studies of the desert communities have a scientific value. In fact, the oasis communities enjoy social interaction, with cohesive social ties between members. They would raise the community awareness of dangers that threaten the demise and extinction of lifestyle that distinguishes rural people aside from others. Especially useful to the research would be the concept of lifestyle that depends on the construction of quality-of-life indicators. This is based on interpreting people’s perception of the quality of life and satisfaction, how angry they are, the frustration of reason, or the adoption of this concept. We can say that this is based on three concepts (lifestyle, standard of living, quality of life) (Schuessler and Fisher 1985).

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In addition, more research is needed on the tourism, because desert regions in Egypt, Sinai, Eastern and Western deserts have rich touristic, natural and archeological sites attracting tourists, in addition to agriculture activities related to the concept of oases. Hence, a great deal of attention should be paid to political stability. Actions that threats political stability at touristic destinations lead tourists to cancel their travel plans. Such events not only affect tourism activity in the country, but also affect the entire region, the relation between tourism, economy and political stability. The more political stability, the more tourism activities flourish, and vice versa.

10 Recommendations Social work is the main axis and basic element to the development and construction of any society. Social work is constituent units of society starting with the individuals, the family, the institution, the community and the state. Therefore, we should pay attention to activating the role of civil institutions for the development of traditional societies, especially with the shrinking state’s role with the rise of global capitalism. This recommendation could be achieved through the following: • Provide the proper environment to conduct developmental social work through educational seminars for women and men. • Encourage families to empower women through the opening of markets to sell women and environmental products. • Establish a network of economic ties between the community development associations and the shops to sell the products of oasis women. • Promote environmental industries and development. • Encourage fish farming which is an appropriate industry using the drainage lakes from agricultural irrigation water. • Encourage the youth to breed the waterfowl (water birds) as a source of wealth in the oases. It is a new field to invest in it. • Maintain archeological sites, buildings and old residential areas, as well as streets, that are valuable international natural heritage. • Develop ceramic crafts, pottery as they are an important environmental craft in the oasis society. They have not yet been exploited extensively. Acknowledgements The author would like to thank all who assisted her while conducting the research studies and fieldwork as well as those who helped her in improving the quality of this chapter through the review processes and editing including the editors of the book.

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References Abdel-Hamid M (1971) A drop of water in the Western Desert. Gabalawy Press, Cairo, Egypt, p 80 (in Arabic) Abu Zaid A (1991) The desert communities in Egypt, North Sinai—Ethnographic study of social structure and organization. National Center for Social and Criminological Research. Cairo, Egypt (in Arabic) Demeiri AA (2005) Siwa—Past and present. Alexandria Press, Alexandria, Egypt, p 54 (in Arabic) Hussein GH (1975) Kharga Oasis—Studies on Egyptian society. Egyptian Book Authority, Alexandria, Egypt, p 47 (in Arabic) Kanani MG (2012) Satellite media and sex. Dar Osama for Publishing and Distribution, Amman p 62 (in Arabic) Khouly O (2002) The environment and issues of development and industrialization. Studies on the environmental situation in the Arab world and developing countries. The World of Knowledge. 285, National Council for Culture, Arts and Letters, Kuwait, September, p 198 (in Arabic) Nureddin AH (2005) Sites and museums locations. Dar Elmaref, Cairo, Egypt, p 96 (in Arabic) Saleh A (1988) The Egyptian family in its antiquity. Egyptian General Book Authority, Cairo, Egypt, p 141 (in Arabic) Schuessler KF, Fisher GA (1985) Quality of research and sociology. Ann. Rev. Sociol. 11:129-149

Geology, Geomorphology, Archaeology and Climate

Geology of Dakhla Oasis, Western Desert, Egypt Elsayed A. Zaghloul

Abstract The exposed Upper Cretaceous—Lower Eocene rock units in the area extending between Teneida and Abu Minqar, is divided into the Taref, Quseir Formations of the Nubian Sandstone Group (Pre-Maestrichtian age), the Duwi Formation (Lower Maestrichtian), the Dakhla Formation (Maestrichtian- Paleocene) subdivided into Mawhub, Baris Mudstone and Kharga Shale Members. In Qur Al-Malik area, the Kharga Shale Member was laterally changed in facies to Qur al-Malik Sandstone Member. The succession of the Tarawan Formation (Upper Danian—Landenian age) represents the Nile Valley facies. The Garra al-Arbain facies was represented by the Kurkur and Garra Formations east of Dakhla Basin at Teneida area. The Quaternary deposits are related to aeolian, fluviatile and lacustrine sediments interrupted by wet and dry phases. Generally, the area is characterized by simple structural elements and has been untouched by strong tectonic forces. Keywords Dakhla Oasis · Stratigraphy · Formation · Member · Tectonic

1 Introduction Dakhla Oasis is located in the heart of the Western Desert, about 500 km from the Nile Valley. Its longitudes is 28°15‘–29°40‘ E and latitudes is 25°00–26°00‘ N (Fig. 1). It occupies a structural basin located about 90–140 m. above sea level and covering an area of about 1400 km2 . It extends 70 km in a WNW direction and the maximum width is about 20 km from north to south. The depression was bounded from the north by the scarp face of Kharga–Dakhla— Abu Minqar plateau which stood high about 400 m. above the floor of the depression while the depression is open from the south and the Oasis lies in the center of the depression. E. A. Zaghloul (B) Geological Applications and Mineral Resources Division, National Authority for Remote Sensing and Space Sciences, 23 Joseph Tito Street, El-Nozha El-Gedida, Cairo, Egypt e-mail: [email protected]; [email protected] © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_3

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Fig. 1 Location map of the study area overlaid over a DEM of the SRTM-03 (USGS 2004; NASA 2005)

The first geological report on the Western Desert of Egypt is made by Zittel who accompanied Rolph’s Expedition in 1883. This pioneering work is followed by several researchers such as Hermina et al. (1961, 2017), Hermina (1990), Awad and Ghobrial (1965), Abbas and Habib (1971), Issawi (1971, 1972), El-Deftar et al. (1970, 1978), El- Azabi and El-Araby (2000), Tantawy et al. (2001), Hewaidy (1990), Mansour et al. (1982) and others. The geomorphology of the area is under different geomorphic zones namely the Northern Plateau, the Scarp Face, the Pediment, Gabal Edmonstone, Dakhla Depression and Playa. The stratigraphy of the area is characterized by the exposed rock unit ranging in age from Upper Cretaceous to Lower Eocene and Quaternary.

2 Geomorphology Dakhla Oasis is a depression that extends more than 80 km from east to west and approximately 30 km from north to south. It rests along the southern edge of a sandstone plateau and the steep escarpment of Paleocene—Lower Eocene limestone defines the northern boundary of the Dakhla Depression (Fig. 1). This scarp is elevated 400–500 m above the oasis floor and the floor of the Dakhla basin is approximately 100 m above sea level, though it varies in elevation across the depression. This oasis occurred as a result of lithological and geological changes occurring since the Early Cretaceous time. Wind was probably the primary agent for excavating

Geology of Dakhla Oasis, Western Desert, Egypt

31

the depressions, although tectonic activity also may have contributed to their formation. All of the oasis depressions occur in areas where hard rocks overlay soft ones; once the hard overlying rock was eroded, the softer rock was hollowed out quickly and stripped away. Geomorphologically, the study area is divided into the following three main distinct geomorphic units: 1. The Dakhla—Abu Minqar Plateau (The limestone plateau) 2. The Scarp Face 3. The Dakhla Depression

2.1 The Dakhla—Abu Minqar Plateau The Dakhla—Abu Minqar plateau makes a part of the main plateau between Kharga and Dakhla depressions. The plateau surface overlooks the Nubian depression of the Western Desert to the south, whereas it stretches northward forming the general surface of the central part of the Western Desert and the floor of the Farafra Depression. The surface elevation ranges from 400 m. to 500 m. above sea level. The surface of the plateau is made of hard, greyish white to yellowish-white limestone’s of Tarawan and Kurkur Formations. The effect of wind erosion is highly manifested in the formation of Yardings and wind flutes especially developed in the limestone ridges which namely Kharafish (Fig. 2). Generally, the main rock surface of the plateau is broken into rugged and rough landscape which is sometimes veneered by limestone rubble.

Yarding

Fig. 2 Google Earth image showing limestone Yarding (Kharafish) at the top of the Plateau

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2.2 The Scarp Face The scarp face of the plateau extends in an undulating line running in an east – west direction for a distance of about 80 km. At Mawhub area, the scarp face extends 80 km. in a northwest direction. The average height of the scarp is 500 m. above sea level and the average difference in elevation between the scarp and the ground level of the depression is 400 m. The shale sequences of the Dakhla Formation with variable thickness from 100 m. to 200 m. cover at least 2/3 of the scarp face which are overlain by a hard limestone unit. Along the edge of the scarp face, the limestone also varies in thickness from 20 m. to 50 m. and whenever the shale section increase in thickness, the limestone unit decreases and vice versa. The scarp face is characterized by steeper cliffs which are dissected by joints, cracks and fissures. The Scarp face extends more than 250 km in a WNW—ESE direction from Teneida tn the east to Abu Minqar to the west and has a irregular outline. The elevation of the plateau surface ranges from 400 m (amsl) and increased to be about 580 m (amsl) due to the northeast direction. It is marked by a number of promontories in which the most important one is located east of Gabal Giftan, al-Qasr and northeast of Balat. The scarp face is made of shale, clay, mudstone, limestone and chalky limestone of Upper Cretaceous and Paleocene ages. The drainage system crossing the area is very irregular and running along the joint planes of the hard limestone and is not well developed in the scarp face.

2.3 The Dakhla Depression The Dakhla depression covers an area about 1200 km2 and extends from Teneida in the east to West Mawhub in the west. It is excavated in the Nubian and Duwi Formations. The depression opens toward south where its floor gradually merges southward into the Nubian Sandstone plain (Brooks 1993). The floor consists mainly of red clays of the Quseir Formation, and is covered in some localities by alluvium deposits that are partially cultivated. Sand dunes frequently cover the scarp face in various localities, as well as areas in the depression of the oasis. The major sand dunes form a north-northwest/south- southeast trend extending to the west of Qaret Mawhub (Edmonstone). Gabal Edmonstone is a single isolated hill in the whole depression of Dakhla. It is a detached portion of the retreated plateau and occurs about 18 km west of al-Qasr. This conspicuous hill has a height of about 465 m (amsl) and about 300 m above the depression plain (Brooks 1993). On the other hand, Gabal Edmonstone divided the Dakhla Basin into two subbasin, i.e., Mut sub-basin for 170 km in length in the east (Fig. 3) and the West Mawhub sub-basin for about 80 km. in length due to the west. The depression is covered by clay, sandstone and silt downwashes from the scarp face and the pediment below. These deposits form extensive lake beds (Playa

Geology of Dakhla Oasis, Western Desert, Egypt

B

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C A

Fig. 3 SRTM DEM for the Dakhla Depression showing the Mut sub-basin (A) the Mawhub subbasin (B) and Gabal Edmonstone (C)

deposits) which are mainly deposited in topographic basins. The most important of these lakes are Deir al-Hagar, and Abu Minqar play. The relief of this plain is low and varying from 100 m. to 150 m. In the eastern part of the plain, several isolated Nubian Sandstone hills litter its surface coated with black surface of desert varnish.

3 Stratigraphy The Late Mesozoic-Early Cenozoic rock units represented in the study area are subdivided into a number of mappable litho-stratigraphic formations (Fig. 4). The sedimentary successions are dipping generally to the north. These formations crop out at the cliff to the north of the depression and they do not appear in the depression itself. The succession are classified generally into two facies, (a) continental with marine intercalations at the lower units, and (b) a transgressive-regressive open marine sequence at the upper units. Two main facies types represent the stratigraphic successions in the study area (Issawi 1972). They are Nile Valley facies and Garra Al-Arbain facies which belongs to the Upper Cretaceous—Lower Tertiary ages (Fig. 4). Quaternary Deposits: Sand Dunes Lake Deposits (Playa) In the study area, the Upper Cretaceous—Lower Tertiary sequence exhibits under the flowing two different facies:

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E2fr E1-E2es

E2dg

E2ga Kurkur Formation

K2dw

K2nqs

Fig. 4 Compiled lithostratigraphic rock units in Dakhla Oasis

– Garra al-Arbain Facies: The Dungle Formation The Garra Formation The Kurkur Formation – The Nile Valley Facies: The Thebes Formation The Esna Formation The Tarawan Formation

K2dw

K2nqs

Geology of Dakhla Oasis, Western Desert, Egypt

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These two facies represented by rocks of various lithology overlying the following units. The Dakhla Formation The Duwi Formation The Nubian Sandstone The age of each unit is determined by its stratigraphic position and its faunal contents. Detailed descriptions are given in the following for each unit.

3.1 Upper Cretaceous—Paleocene Rock Units 3.1.1

Nubian Sandstone

The term “Nubian Formation” was first used by Russeger (1837) to denote a huge sandstone section overlying the basement rocks in Nubian region in Upper Egypt. The Nubian Sandstone section was divided into several mappable formations in the field (Klitzsch et al. 1979 and others). In the present work, the Nubian Sandstone (Group) is divided into two following distinctive formations:

3.2 Taref Formation This formation represents the basal unit exposed in the southern and eastern parts in Dakhla Basin (Fig. 5). Lithologically, the formation consists of yellowish to light brown cross-bedded sandstone, fine to coarse grained, stained with iron oxide, contain thin shale and marl intercalations. The top surfaces are covered with black color of desert varnish. The formation is non-fossiliferous and contains plant remains and petrified wood. The base is unexposed and the total thickness is about 100 m. as measured at Gabal Taref type section (Awad and Ghobrial 1965; Issawi 1972). The presence of Haplophragmoides spp. and Trochammina spp. within the shale interbeds may indicate deposition in normal water salinity. The age of the Taref Formation was previously assigned to the Senonian (Coniacian–Santonian) age. On the other hand, the sandstone beds of the Taref Formation pass gradually upward into the overlying Quseir Formation. South of Dakhla Basin, the Taref Formation conformably overlying the older rock units (Maghrabi and Sabaya Formations, Fig. 5).

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Qur El-Malik

G. Edmonstone

Mut

Tenida

Fault

Fig. 5 Geological map of Dakhla Oasis (modified after Mansour et al. 1982; Conoco 1987; Hewaidy et al. 2017)

3.2.1

Quseir (Mut) Formation)

The term Quseir Variegated Shales was first introduced by Youssef (1957) who descried the clay and siltstone section overlying the Taref Sandstone section. Issawi (1971) described this unit under the term Quseir Clastic Member. Barthel and Hermann-Degeen (1981) applied the term Mut Formation. It forms the lower slope of the main scarp face and the pediment bounding the Dakhla Depression as well as a part of the depression itself. Lithologically, yt consists of about 65 m. of varicolored clay, sandy clay and shale with minor sandstone streaks. The formation can be divided into three units: (1) The basal 30 m. of brick red subunit, the green glauconitic siltstone subunits in (2) the middle and (3) the upper 30 m. alternating glauconitic brown sandstone and gray sandy clay. The lower and upper units were described by Omara et al. (1976) using the terms Mut and al-Hindaw Members respectively. The Quseir Formation conformably overlain by the Duwi Formation which is considered of Lower Maestrichtian age, thus the Quseir Formation is assumed to have been deposited in Upper Campanian age.

3.2.2

Duwi Formation

The Duwi Formation is the phosphate bearing rock unit that stratigraphically located at the top of the Quseir Formation and underlies the Dakhla Formation. It was first described by Youssef (1957) under the term Phosphate Formation in Gabal Duwi in the Eastern Desert of Egypt. The Duwi Formation conformably overlies the Quseir Varigated Shale and underlies the Dakhla Formation (Figs. 5 and 6). Lithologicaly, the

Geology of Dakhla Oasis, Western Desert, Egypt

37 East

West Datum ---

Tarawan FormaƟon Qur El-Malik Sandstone Member Kharga Shale Member Baris Mudstone Member Mawhoob Shale Member

50 m. 25 0 0

5

10KM

Fig. 6 Generalized section across Edmonstone—Abu Minqar area (after Mansour et al. 1982)

formation consists of phosphate beds interbedded in alternating claystone, sandstone, glauconitic sandstone, siltstone and conglomeratic phosphate. The total thickness is about 20 m, and the upper part is marked by the presence of about 0.5 m. of greyish white limestone capped with about 0.5 m. of hard pink limestone bed rich in Isocardia khargensis sp. (Abbas and Habib 1971), forming the top surface of the formation and the top of the pediment bounding the Dakhla depression. The Duwi Formation is highly fossiliferous with Inoceramus regular is Pervenguier, Roudaireia drui Munier-Chalmas, Roudaireia dakhlensis Abbas, Lopha villei Coqu and, Chark teeth and bone fragments and others. The fossil assemblage suggests a lower Maestrichtian age. It is possible to conclude that the Duwi Formation in the Dakhla basin was deposited in continuity with both Quseir and Dakhla Formations of the Campanian age.

3.2.3

The Dakhla Formation

According to Said (1962) who initially applied the term, “Dakhla Shale” to 230 m thick section of shales and mudstones layers overlying the Duwi Formation and underlying the Tarawan Formation (Fig. 5). It can be divided into three units according to Awad and Ghobrial (1965): Kharga Shale Member at the top (115 m. thick), Baris Oyster Mudstone Member at the middle (135 m. thick), and Mawhub Shale Member at the base (70 m. thick). The Mawhub Shale Member forming the lower one overlies the Duwi Formation and underlies the Baris Oyster Mudstone Member of the same formation. It consists of grey to black fissile calcareous silty shale’s inerbedded with siltstone. It is assigned to the early Maastrichtian age based on its foraminiferal content.

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According to Awad and Ghobrial (1965), Baris Oyster Mudstone Member is composed of shale, limestone, sandstone, and siltstone rich in fossils mainly with Exogyra overwegi which dates to the Middle Maastrichtian age. The Kharga Shale Member contains shale, siltstone, sandstone, and limestone. It lies along the scarp face stretched from west of Gebal Edmonstone to Qur al-Malik area, where the member wedges out and is replaced by Qur al-Malik Sandstone Member (Figs. 5 and 6). The Kharga Shale Member appears again toward west of Qur al-Malik area (El-Deftar et al. 1970). The term Qur al-Malik Sandstone Member was applied by Mansour et al. (1982) to describe the succession of calcareous band of sandstone and siltstone intercalated with grey clay band exposed along the scarp face at Qur al-Malik area which located about 90 km. The thickness ranges from 1 to 30 m. and crops out between the Tarawan Formation at the top and the Dakhla Formation at the base (Fig. 6). Generally, the Dakhla Formation is rich in fossils such as: Exogyra overwegi, Inoceramus regularis, Nostoceras cf. helicinum, Libycoceras spp. Globotruncana gansseri which assign the age of the lower members to the Late Campanian while the upper member contains Globigerina pseudobulloides, Globigerina triloculinoides which point to the Lower Paleocene.

3.3 Paleocene—Lower Eocene Rock Units Two main facies types form the stratigraphic successions in the study area overlying the Dakhla Formation: (1) Nile Valley Facies represented by the Tarawan Formation at the top of the scarp face, and (2) Garra al-Arbain Facies (Issawi 1972) composed of the Kurkur and Garra Formations (Issawi 1968). It is found only in Teneida section near Abu-Tartur plateau and west Dakhla at Qur Al-Malik section as illustrated in (Fig. 5). These facies correspond Upper Cretaceous—Lower Eocene rock units. The distribution, as well as the lithological characteristics of each of these formations in the study area, is described below.

3.3.1

Nile Valley Facies

Tarawan Formation The Tarawan Formation is the upper part of the scarp face of the plateaus bounded the Dakhla Depression from the north (Fig. 7). It conformably overlies the Dakhla Formation. It is composed mainly of 10–55 m. of snow white to yellowish white hard, thickly bedded chalk and chalky limestone with few marl and shale intercalations and forming a wall. The formation is well developed and extended between Teneida in the East and Abu Minqar in the West. The sediments indicate a deep facies display gradual lateral and vertical changes in lithology. According to Hermina (1990), the

Geology of Dakhla Oasis, Western Desert, Egypt

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Ta Dk Duw

Fig. 7 Dakhla Formation (Dk) overlying the Duwi (Duw) and underlying the Tarawan Formation (Ta), North of al-Qasr scarp (Photo taken by author)

formation falls within the Globorotalia velascoensis zone which can assign the age to Late Paleocene age.

Esna Formation The Esna Formation (Said 1962) consists of (30–35 m) of soft, green color, fissile, gypseous shale intercalated with thick bands of marl and limestone near the top. It lies in the north of Qur al-Malik area, between the Tarawan Formation and the Thebes Formation. A change in facies from shale/marl to carbonate is observed in the eastern part of the area under consideration where the term Gara Formation was applied by (Issawi 1968). The formation is rich in Globorotalia velascoensis, Globorotalia subbotinae Morozova, Globorotalia broedermanni Cushman and Bermudez, Globorotalia wilcoaensis Cushman and Ponton, Globigerina soldadensis Bronniman, Nummulites solitartus Nummulites fraasi and other. The assemblage fossils indicate a Late Paleocene age for the lower part of the formation and the Early Eocene Ypresian) age for the Upper part.

Thebes Formation The Thebes Formation (Said 1962) is composed of (2–9 m) of limestone, marl and shale. The limestone is thinly bedded in the lower part and contains chert bands and concretions. The formation conformably overlies the Esna Formation with a gradational contact. The formation includes Nummulites deserti, Nummulites atacicus,

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Nummulites subramondi, Operculina sp., Pecten sp., Lucina sp. As attested by the nummulites, the age is Early Eocene (Ypresian).

3.3.2

Garra al-Arbain Facies

Kurkur Formation El-Deftar et al. (1970) mapped a thin dark yellow to brown layer representing the unconformity surface between the Kharga Shale Member and Qur al-Malik sections. The thickness is about 40 m. in Teneida and reduced to the west and completely missing in north of Mut. It consists of 40 m. of argillaceous, dolomitic and oolitic reef-like limestone, silty shale, and marl. The limestone is fossiliferous with Cardita wegneri, Cardita tenedensis, Ostrea orientalis, Turritella spp. The faunal assemblage assigns the age to Upper Paleocene (Landenian).

Garra Formation This name was first introduced by Issawi (1968), to describe the thick limestone beds at the top of Gebal Garra. It overlies the Kurkur Formation at Abu Tartur Plateau and forming the inner scarp and ridges. Lithologically, it is made of a thick limestone, slightly chalky and partly siliceous, with clay bed near the base. The formation is fossiliferous with Ventreculites sp., Globorotalia pseudomenardi Plummer, Globogirina angulate, Ananchytes fakhreyi Fourteau, Ostrea Osiris, Natica dakhlensis and others. The assemblage fossils assign the age of the Garra Formation by Issawi (1968) to Landenian at the base and Lower Eocene (Ypresian) at top.

3.4 The Quaternary Deposits The Quaternary deposits cover relatively extensive topographic low areas in the Dakhla Depression. These are of continental origin varying from freshwater to aeolian. These deposits may be classified into the following units:

3.4.1

Lake (Playa) Deposits

These deposits occupy the topographically low areas at the foot of the scarps and pediment. Three localities covered by these deposits are recognized at Deir al-Hagar (about 150 km2 ), West Mawhub (about 10 km2 ) and on the plateau surface northeast of Abu Minqar (20 km2 ). This unit is represented by the Deir al-Hagar Playa which is located close to Deir al-Hagar Temple. It is a semicircular basin covering about

Geology of Dakhla Oasis, Western Desert, Egypt

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Fig. 8 Dikaka features in the sandy silt of Deir al-Hagar Playa deposits (Photo taken by author)

2.5 km2 and nearly flat surface with a remnant of a recent playa in the forming of yardings. The playa sediments were classified according to Zaghloul 1999, into three stratigraphic units namely A, B and C at the top. The lower unit (A) contains Neolithic remains such as lithic artifacts, bone fragments and Ostrich eggshell fragments. The total thickness is about 3.10 m. and mainly consists of horizontal alternating bands of soft, friable sand, clay and silt with plant remains, sand clay with Dikaka structures (Fig. 8) and rare limestone pebbles and gravels. The deflated surface was dissected by an ancient system of irrigation canals from Roman and Pre-Roman times (Zaghloul 1999).

3.4.2

Sand Dunes

Sand dunes cover the al-Qasr, Mawhub and Abu Minqar areas. These deposits are represented by extensive sand dunes and sand sheets that cover the areas under consideration. This belt is known as the East Farafra (Karawin Dune Field) where the sand is arranged into parallel longitudinal dunes or seifs dunes oriented in a northwestsoutheast direction, the direction of the prevailing wind. The dune field originates from the plateau north to Dakhla Depression enters the plateau and continues with minor breaks in nearly southeastern direction. Patches of sand sheets and barchans dunes exist at the foot of the scarps and along the slop of al-Qasr to West Mawhub

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escarpment while the Abu Minqar is located at the eastern edge of the Great Sand Sea. The Great Sand Sea formed of similar northwest-southeast running dunes mainly of the seif type and extends for more than 200 km to the Libyan border. Occasional gaps or corridors between the dunes are present which are covered by different rock units. Salt crusts resulting from capillary rising groundwater build up 10–20 cm thick layers and in some places intercalate the lacustrine deposits (Embabi 2004; Haynes et al. 1979).

4 Geologic Structures The structural elements in the Dakhla area are the result of typical of the stable shelf tectonic elements. Faults and a large scale gentle fold are reflected on the surface. The area characterized by a simple geologic structure and very gentle northwardly regional dips. According to Hermina et al. (1961), Dakhla Oasis can be considered as a major broad syncline and the area structurally characterized by symmetrical folds with gentle dips. At Edmonstone area, a broad syncline with NE- SW axial trend and plunging towards the northeast is recorded. Faults are located in the southeastern part of the study area. These faults were also recorded by Hermina et al. (1961) and Omar et al. (1976) and they have a limited vertical displacement. A series of small faults were observed west of Qur al-Malik area, where they dip towards the northeast. All these faults are nearly vertical and of the normal type. They run for a distance of about 40 km., in a northeast-southwest direction. The downthrows range from 15 to 25 m. El Deftar et al. (1978), measure a group of mega-joints possesses very high angles of dip up to vertical. The joint having a N 45 W, N 20 E and extends up to 1000 m The NW- SE joints dissecting the hard limestone plateau forming prominent narrow furrows and ridges which have a local name “Kharafish” at the top of the plateau (Fig. 2). The morphological shape of the escarpment northwest of West Mawhub area suggests the presence of a fault running parallel to the scarp in a northwest direction.

5 Conclusions The Quseir Formation is the oldest rock unit exposed in the study area underlain by a thick succession of the Taref Formation and overlain by the phosphate bearing rock unit Duwi Formation. The Duwi Formation is overlain by a thick sequence of Dakhla Formation which divided into three members, i.e., the Mawhub Shale Member at the base, Baris Mudstone Member at the middle and the Kharga Shale Member at the top.

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During the middle Maastrichtian time, the west Mawhub area was slightly uplifted and due to the environmental changes, the Kharga Shale was laterally changed in facies and become sandstone and sandy silt with limestone intercalations in which the term Qur al-Malik Sandstone Member was applied. It is believed that this member was deposited in an inner marine shelf.

6 Recommendation It is recommended to study in detail the Duwi Formation as an extension of the Phosphate bearing rock unit in Abu Tartur Phosphate Mining Project in Kharga Oasis.

References Abbas HL, Habib MM (1971) Stratigraphy of west Mawhoob area, South western Desert, Egypt. Institute Desert d’Egypte, Bulletin 19(2):47–107 Awad GH, Ghobrial MG (1965) Zonal stratigraphy of the Kharga Oasis. Geological survey of Egypt, Paper 34, 77 pp Barthel KW, Herrmann-Degen W (1981) Late Cretaceous and early tertiary stratigraphy in the great sand sea and its SE margins (Farafra and Dakhla Oasis). SW Desert, Egypt. Mitt Bayer Staatssamml Fur Palaont Hist Geo 21:141–182, Munchen Brooks I (1993) Geomorphic indicators of Holocene winds in Egypt’s Western Desert. Geomorphology 56:155–166 Conoco (1987) Geological map of Egypt, Sheet NG35 SE, Dakhla, 1:500,000 Edmonstone A (1824) Voyage à deux des oasis de la Haute Egypte, Nouv. Ann. des Voy. Paris, tome XXI, 5–74 and 145–177 El-Azabi MH, El-Araby A (2000) Depositional cycles: an approach to the sequence stratigraphy of the Dakhla Formation, west Dakhla- Farafra stretch, Western Desert. Egypt J Afr Earth Sci 30:971–996 El Deftar T, Issawi B, Abdallah AM (1978) Contributions to the geology of Abu Tartur and adjacent areas: Western Desert Egypt. Ann Geol Surv Egypt 8:51–90 El Deftar T, Said M, Zaghloul EA (1970) Geology of Dakhla Oasis. Geological expedition 14/69, Geological survey of Egypt. Internal report El-Desoky H, El-Rahmany M, Farouk S, Khalil A, Fahmy W (2015) Geochemical characteristics of goethite-bearing deposits in the Dakhla–Kharga Oases, Western Desert, Egypt. Int J Sci Eng Appl Sci (IJSEAS) 1(8), November ISSN: 2395–3470 Embabi NS (2004) The geomorphology of Egypt land forms and evolution Volume I, Nile Valley and the Western Desert. The Egyptian Geographical Society. Special publication. Cairo Ghorab MA (1956) A summary of a proposed rock stratigraphic classification for the cretaceous rocks in Egypt. Paper presented at the meeting of Geological Society Egypt, Cairo, June 12 1956 Haynes CV Jr, Mehringer PJ Jr, Zaghloul EA (1979) Pluvial lakes of northwestern Sudan. Geogr J 145:437–445 Hermina M (1990) The surroundings of Kharga, Dakhla and Farafra Oases. In: Said R (ed) The geology of Egypt. Balkema, Rotterdam/Brookfield, pp 259–292 Hermina MH, Ghobrial MG, Issawi B (1961) The geology of the Dakhla area. Geological survey of Egypt. 33 pp

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Hewaidy AA, Farouk S, Bazeen YS (2017) Sequence stratigraphy of the Maastrichtian-Paleocene succession at the Dakhla Oasis, Western Desert, Egypt. J Afr Sci 136:22–43 Issawi B (1968) The geology of Kurkur- Dungle area: geological survey, Egypt. Paper 46, 102p Issawi B (1971) The geology of Darb El-Arbain, Western Desert. Ann Geol Surv Egypt 1:53–92 Issawi B (1972) Review of upper cretaceous—lower tertiary stratigraphy in central and southern Egypt. Am Assoc Pet Geol Bull 56:1448–1463 Klitzsch E, Harms JC, Lejal-Nicol A, List FF (1979) Major subdivision and depositional environments of Nubia strata, southwestern Egypt. Bull Am Assoc Perol Geol 63:974–976 Mansour HH, Issawi B, Askalany MM (1982) Contribution to the geology of west Dakhla oasis area, Western Desert, Egypt. Ann Geol Surv Egypt 12:255–281 Russeger J (1837) Kreide und Sandstein: Einfluss Von Granit auf letzteren. Neues Jahrb. Mineralogi Abd, pp 665–669 Omara S, Philobbos ER, Mansour HH (1976) Contribution to the geology of the Dakhla Oasis area, Western Desert, Egypt. Bull Fac Sci, Assiut Univ 5:319–339 Said R (1962) The geology of Egypt. Elsevier, Amsterdam Tantawy AA, Keller G, Adatte T, Stinnesbeck W, Kassab A, Schulte P (2001) Maastrichtian to Paleocene depositional environment of the Dakhla Formation, Western Desert, Egypt: sedimentology, mineralogy, and integrated micro- and macrofossil biostratigraphies. Cretaceous Res 22:795–827 Youssef MI (1957) Upper Cretaceous rocks in Kosseir area. Bull Inst Desert Egypt 7:35–54 Zaghloul EA (1999) Geoarchaeology and hydrogeology of Deir El-Hagar Playa, Dakhla. Bull Geo Soc LXXII(72):81–90

Geomorphology of Dakhla Depression Atef Moatamed A. Mohamed

Abstract This chapter deals with the geomorphological units of Dakhla Depression from a wider scope of view. The major units are tabular plateau, escarpment, piedmont, peneplain, dune fields, inner depressions, and springs. The method of analysis is based on the geomorphological system connecting the sub-units together. In relation to interpreting up-to-date remotely sensed data, information sources are variable, particularly analysis of prior literature, ancient and recent maps. Since the author works in the area periodically, field observations are included in this review and enhanced by ground photographs. Keywords Western Desert · Dakhla Depression · Arid land geomorphology · Sand dunes · Playa and springs

1 Introduction Dakhla Depression (see Fig. 1) represents one of the series of structurally-oriented desert depressions below the scarp of the Libyan Plateau. Climatic conditions have been classified as hyper-arid in a region lying between the two parallels of 28° E and 30° E, and the two latitudes of 24° 40 N and 26 N. Mut, the urban center and the capital city of Dakhla Oasis, lies almost in the midway between the Nile Valley in the east (350 km) and the borderline with Libya in the west (390 km). This central geographic location is also noticeable between Mut and East of Uwainat agricultural project (380 km) in the south and Bawity town in Bahareya Oasis (420 km) in the north. Dakhla Depression in its wider border extends 200 km WNW to ESE direction and is up to 50 km wide northeast to southwest. There is no fixed contour line to delineate the depression basin. Brooks. I. 1993 adapted that the depression is confined within the 140 m contour line. The current study tends to deal with a wider view (up

A. M. A. Mohamed (B) Faculty of Arts, Cairo University, Cairo, Egypt © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_4

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Fig. 1 Location map of the study area

to contour 400 m) so that the total area of the depression reaches 12,000 km2 (see Fig. 2). Geological map (Fig. 3) shows that the exposed sedimentary formations range from lower Cretaceous to Paleocene. Pleistocene sediments are widespread and covering older rock types. The major formations in the study area are: (Lower Cretaceous) – Six Hills: Flood plain sandstone and channel deposits. – Abu Ballas: Marine claystone; mudstone; siltstone and shoreline sandstone. – Sabaya: Flood plain sandstone and channel deposits (see Fig. 4). (Upper Cretaceous) – – – –

Maghrabi: Coastal mud plain deposits and channel sandstone. Taref: Fluviatile and Aeolian sandstone. Quseir: Varicolored shale; siltstone and flaggy sandstone (see Fig. 5). Duwi: Phosphate beds and black shale; glauconitic sandstone, overlay by white limestone. – Dakhla: Dark grey marine shale with calcareous and sandy intercalations (see Fig. 6). (Paleocene): – Garra: Chalky limestone. – Kurkur: Marl and marly limestone. – Tarawan: Chalk and limestone.

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Fig. 2 Contour map of Dakhla depression

Fig. 3 Geological units in Dakhla area

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Fig. 4 Qulu’a EL Sabay hills—near Teneida

Fig. 5 Quseir formation, Teneida–Eastern Dakhla

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Fig. 6 Fine-grained clastic sediments of upper cretaceous are typical segments of Dakhla scarp— Mawhub area

2 Regional Geomorphology Recent geographic and geological findings lead us in this chapter to deal with Dakhla “depression” rather than Dakhla “Oasis”, since the geomorphological development in Dakhla region is closely interrelated with the wider scope of landforms in the integrated system of the southern portion of Western Desert of Egypt (previously “Libyan Desert”). There are at least four reasons behind adopting this wider geomorphologic vision. Firstly, from a historical point of view, the two oases of Kharga and Dakhla were named “oasis” in the Classical times, with reference to Kharga and Dakhla together as “Oasis Magna” (great oasis) while Bahareya was “Oasis Parva” (small oasis) (see Ball 1942). During the middle ages the two depressions comprising “Oasis Magna”

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were tied together by the caravan route named “El Ghabari” which is occupied now by the modern asphaltic road. Secondly, the geological integration of southeastern part of Western Desert is so obvious that the region extends about 300 km east-west from the Eocene plateau in Kharga till the Great Sand Sea. This extension is a broad structural unit named “Kharga-Dakhla” basin. Interpretation of radar images has changed some old concepts about aridity of the North African Sahara. Recent studies shed more lights upon the buried fluvial channels dominating the Sahara landscape over the Late Paleogene and the Neogene. Issawi and Youssef (2016) found that Eastern Sahara had undergone wet phases followed Early Eocene transgression of the Mediterranean Sea, which resulted in shaping the now extremely flat, featureless landscape. The above mentioned study had concluded that the fall in base level associated with the Messinian desiccation of the Mediterranean Sea promoted down-cutting and extension of river systems throughout much of North Africa and South Europe. On the same time, corridors of fresh water across the North African Sahara are now distinguished through Radar images. Two important rivers dominated eastern Libya, the Sahabi in the west and the Kufra in the east, though in the Early Pliocene the latter captured the former and control the paleohyderological system in eastern Libya. The third one is an important fresh water corridor; the Gilf River, which connected the Uwainat—Gilf high in southwest Egypt with the Mediterranean Sea in the north. Figures 7 and 8 show the location and morphology of the supposed Gilf River. It is expected that the forthcoming years of research will shed more lights on the relationship between Dakhla Depression and the supposed Gilf River. It might be clear that most of the depressions in the Western Desert of Egypt, especially KhargaDakhla—Farafara were hydrologically connected with this paleo Gilf River. Thirdly, the detailed topographic analysis clarifies that Abu Tartur plateau represents, in fact, a linkage node, rather than a separation wall, between the two depressions of Kharga and Dakhla. Few native old people in the region still know the ancient caravan routes across the backward wing of Abu Tartur plateau, where it is connected, till the first quarter of the twentieth century, the whole area with the third depression of Farafra. In this context, Ain Amur (see Fig. 9), Darb El-Tawil, Kharafesh, and El Dakar dunes were well-known “short-cuts” passes (Naqbs) across the tabular land of the plateau, bypassing the lower depression and wetlands, moving faster from Kharga via Dakhla to Farafra. Finally, with the analysis of recent remotely sensed data it becomes clear that it is not advisable to trace the extension of El Gilf El-Kebir plateau in the southwestern corner of Egypt in isolation from the other surrounding regions of Eastern Sahara. Actually, the northeastern flank of El Gilf El-Kebir plateau is buried underneath the sand dunes and reaches the southern part of Dakhla basin, where the “six hills” famous locality represents the most eastern tip. In their preliminary reconnaissance field trip to Uwainat area, Said M. and his colleagues (see Said et al. 1994) had found that the area is covered by Precambrian rocks, Paleozoic and Mesozoic sediments intruded by Phanerozoic igneous rocks and

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Fig. 7 Schematic paleodrainage lines (supposed by Issawi and Youssef 2016). 1, 2, 3, 4 and 5: Schematic drainage lines of Gilf, Kufrah, Sahabi, Bashu and Serir Tibisti River system

covered by Quaternary sediments with a great number of faults, mainly of NortheastSouthwest trend. The prominent feature there is Ring complexes which include Gabal Archenu and Gabal Al Uwainat which composed mainly of granites to syenites and in age from Ordovician to Devonian. The main mass of Al Uwainat Ring complex is formed of an outer ring of coarse-grained quartz-syenite and an inner ring of pink, mediumgrained granite. Three subsidiary rings are less well exposed and are composed of quartz syenite and trachyte. Some signs of mineral deposits are known in the area. Most important among these are lenses of quartz-magnetite rock associated with quartzofeldspathic gneiss. The highest value recorded for gold was 0.15 ppm and for silver was 1.2 ppm (Said et al. 1994, p. 555). For the southern regional extension of the study area, Issawi et al. (2009) identified South Kharga—Dakhla Pediplain considering it as the northern extension of the Nubia—Shab Pediplain. This Pediplain continues at the base of the Kharga—Dakhla scarps running for more than 500 km. The prominent geomorphic feature on the surface of this pediplain is residual hills. Southward, this pediplain extends 250 km till it merges into Atmur El Kibeish Peneplain. To the west, the pediplain disappears below the dune belt of the Great Sand Sea.

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Fig. 8 Egyptian drainage systems during late Oligocene—Miocene (after Issawi and Youssef 2016, p. 7)

Fig. 9 Ain Amur—Abu Tartur

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According to the above mentioned study this pediplain reaches a huge stretch (70,000 km2 ) and is dissected by many E-W faults giving rise to scarps of low altitudes, 40–50 m above the surface of the desert, isolated hills, ridges and many small local depressions. The altitude of this pediplain ranges from 100 m amsl at its eastern side near Kharga scarp to 500 m amsl near the twin hills of Abu Ballas at the edge of the Sand Sea (see for more details Issawi et al. 2009). Dakhla depression is also geophysically connected with the wider region. In their research about the Nubian Sandstone Aquifer System (recharge, depletion, and connectivity) Mohamed et al. (2016) studied the other sub-basins: Dakhla, Northern Sudan Platform, and Kufra. The importance of Dakhla exceeds its regional geomorphology to the global one, especially with respect to paleogeography. According to Moawad et al. (2008) Mawhoob area revealed a prominent accumulation of vertebral bones that delineate outlines of huge vertebral animals (more than 10 m in length) indicating that these skeletals were associated with large vertebrates that lived during the Mesozoic period. The previously mentioned study concluded that these animals are reaching its climax through the Upper Cretaceous and extinct by the close of the Cretaceous time. The importance of this discovery lies in its standing mostly upon two facts; the first is the intact relationship of these bones. The second is the stratigraphic position where these bones were accumulated. The bones herein precisely mark the (K/T) boundary (see for details Moawad et al. 2008). These results were affirmed by recent findings of skeletons of dinosaurs in Teneida area (Eastern Dakhla), which becomes world widely known as Mansourasaurus: a Late Cretaceous dinosaur dispersal between Europe and Africa (see for more details Sallam et al. 2015).

3 Principal Geomorphological Units 3.1 Plateau and Escarpment The tabular landscape of the Western Desert of Egypt is known in the previous literature as “the Libyan plateau” where the most prominent geomorphological landmark in the study area is a transverse scarp wall generally runs ESE-WNE for about 300 km (see Fig. 10). The promontories and embayments along the scarp line have been ascribed by Brooks to be developed on synclinal and anticlinal swells (see Brooks 1993). This scarp is structurally composed of cuesta cliff exceeds 45° in slope (Fig. 10). The cuesta scarp overlooks Dakhla Depression and facing south (see Fig. 11), while the gentle slope faces towards northwestern direction till it reaches Farafra Depression. Most of the tabular surfaces behind the cuesta wall are covered by sand dunes

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Fig. 10 Slope map

Fig. 11 V-Shaped valley—Bab El Gaisoum area

which extend to tabular land of another cuesta-shape plateau named Al Qus Abu Sai’d. The Dakhla scarp does not rise up suddenly in the region, it is actually the western extension of northern Kharga cliffs, which in turn is the extension of the plateau named by Haynes (1984) “Al-Arba’in Desert” after the famous caravan route of Darb El-Arba’in (see for details Said 1990).

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Fig. 12 Classical view of the Escarpment, Bir El Gabal area

The geological succession in the scarp-cliffs is decisive in the rate of slope retreatment. The lower formation is composed of shale and friable sand while the upper one is limestone (see Fig. 12). There are different pieces of evidence for the paleo-karst in the upper formations. Some of these karstified rocks already collapsed on the lower slope sector. The pediment zone varies from 3 to 6 km. The scarp is topped by Limestone caps, which are vertical small walls vary in thickness between 20 and 30 m and well-seen from any point in the depression of Dakhla. Since caps are dissected by vertical joint wearing this limestone layer into semi-independent blocks (see Fig. 13), the non-trained eyes might mislead them with a row of high old white buildings (Fig. 14). The so-called Libyan plateau behind the scarp line of Dakhla (above 500 m) is a vast upland (25,000 km2 ), composed of different landforms, the most prominent are yardang (Kharafesh in local naming) in addition to terraces-like ridges on the transitional zone between scarp and tabular lands. Classical geomorphic features are abundant along the scarp, especially V-shaped incised valleys, mass movements, and falling dunes. Brooks (1993) found that karstification on the plateau zone is dominated by an extensive field of yardangs and rolling topography which resemble the same degraded karst, possibly of ‘cockpit’ form of paleokarst described by El-Aref above Bahareya Oasis (El-Aref et al. 1987). Dakhla scarp could be classified from east to west into four sections: Abu Tartur which is a semi-circular arc representing the transitional sector that connects together the two depressions of Kharga and Dakhla. Abu Tartur is a semiattached rounded plateau. The perimeter is 190 km and the total area is 3000 km2 . It overlooks the floor of Dakhala Depression in two inner close basins: EL-Zayyat and Abu El Egl. Wadi El-Battikh (valley of watermelon) is the largest one draining the escarpment and even has a typical small alluvial fan. The term “El-Battikh” is used

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Fig. 13 Three-dimensional view to Dakhla scarp and depression floor

Fig. 14 Cultivated playa—Mawhoob area

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in the two depressions of Kharga and Dakhla for the effect of spheroidal weathering processes in limestone disintegrated boulders thrown on the free slopes or valley bed. Karst landforms are widespread, especially tufa and sinkholes (see Fig. 15). Abu Tartur sector is occupied by badland topography. Here slope has about 500 km2 of what called “all-slope” topography, where no scree, neither debris nor talus cones or any segments of the classical slope profile. Fig. 15 Sinkhole, 30 m deep—Abu Tartur plateau, northeastern location near Kharga Depression

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Fig. 16 Drainage networks

The all-slope is dissected vertically and equally by parallel faults. Short valleys (15–25 km long) are highly controlled by fault orientation, hence they typically elongated valleys, These wadies have an internal discharge into the closed depressions of “El Zayyat” and “Abu El Egl (Fig. 16).” Teneida, a 40 km long, dissected by a series of tiny wadies, gullies and rills. The northern part of this escarpment is opened by fault-oriented valley making a historical pass (Naqb) for caravan routes into the Nile valley. The old caravan route named “EL Darb El-Taweel” (the long road). Recently this route is developed into an asphaltic highway to connect Teneida with Cairo, via Manfalut (Assiut governorate). Work in this road is still in the beginning and it does not continue without facing some obstacles of sand encroachment (see Fig. 17). Gebel Gifata, a 55 km free slope wall extends E-W overlooking the two inner depressions of Teneida—Balat and Mut. Westward, Gifata changes its name near El-Qasr into Bab El-Gaisoum. Typical slope forms and processes are widespread in this region (see Figs. 18 and 19). In front of Bab El-Gaisoum stands the detached hill of “El-Shaykh Mawhub,” an original local name changed into “Edmonston” on the European maps since the pioneer travel of Sir Archibald Edmonstone in 1822 (see Fig. 20). This detached hill is vital in strategic and regional security of the region. It also has geoarchaeological importance as it surrounds the two famous localities of ElMuzawaqa and Deir El-Hagar.

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Fig. 17 New road from Balat to Manfalut across falling dunes

Fig. 18 Quaternary breccia—Gharb El Mawhub

3.2 Depression Floor The floor of Dakhla Depression (see Fig. 21) is composed of series of inner subdepressions; they are, from east to west, as follows:

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Fig. 19 Rock falls and blocks sliding ami sand deposition—Bir El Gabal

Fig. 20 The detached hill of Edmonston—view from El Qasr

– El Zayyat. This is oval lowland of 290 km2 and 25 m below the surrounding lands of Dakhla Depression. It has no historical springs or wells, and land reclamation projects started in the area only 20 years ago. Field observations indicate that because of the soil salinity the land reclamation is not successful. The results of the geologic and hydro-geological studies reveal that the Six Hills sandstone aquifer represents the sole aquifer in El Zayyat area where the groundwater flow is generally from the southwest to northeast. Geological map shows clearly that Six Hills formations are not exposed on the surface in El-Zayyat sub-depression and recorded only in the subsurface and southward beyond.

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Fig. 21 Aspects of slope in Dakhla Depression

According to Aggour et al. (2012), Six Hills formation represents the oldest sedimentary rock unit, where it is unconformably overlies directly the Precambrian basement rocks and underlying the Abu Ballas Formation. This formation is mainly composed of ferruginous sandstone, vari-colored, medium to coarse grained, moderately sorted with clay interbeds. The previously mentioned study revealed that the average transmissivity and hydraulic conductivity of Six Hills sandstone aquifer are 1227 m2 /day and 7 m/day respectively. The groundwater salinity here ranges from 227 to 1147 ppm. It is suitable for all purposes. The cultivated area in El-Zayyat is 1200 feddan (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) (about 5 km2 ). The total number of productive wells is 12 wells. – Abu El Egl. A semi-closed inner small depression with an area of 130 km2 . Here there are neither springs nor attempts for digging wells. Moreover, Geoarcheological interest is noticeable to this area according to its paleogeography and development of playa lakes (see for details El Rasheidy 2000). – Balat. This is one of the three inner depressions that constitute the proper “oasis” of Dakhla beside Mut and El-Qasr. The total area of this sub-depression is 1200 km2 , and is dotted by hundreds of springs and wells in addition to numerous small hamlets (Ezba). – Mut. A famous inner oasis with an area of 550 km2 . Mut has more than 50% of the total springs and wells in the Dakhla oasis (see Fig. 23).

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– El Qasr. This western sub-oasis has a total area of 765 km2 . While the rest of sub depressions orients East–West, El Qasr area extends from north to south, where the town of El Qasr lies very near to the scarp in the north and the town of E-Qalamoun lies in the south. – West Mawhub. On the western side of Edmonstone, detached hill stretches a semi—rounded depression covered by thick sand sheets. The area is about 2000 km2 , but the reclaimed area (initiated some three decades ago) does not exceed 250 km2 . Dakhla Oasis is in origin a floor of paleo lakes or playa. Western Desert of Egypt has more than 100 plays, 25 of them in Dakhla. Age of sediments in these playa ranges from late Pleistocene to Holocene (see Figs. 22 and 23). Radiocarbon dating of some pieces of ostrich egg-shells found on the top of the sediments gave an age of around 20,000 years. Artifacts found around some of this playa (Abu El Egl, for example) are from the Middle Paleolithic period (see Ashour et al. 2005; Donner et al. 2015; Embabi 2018). According to topographic maps (Fig. 24) published in 1932 (scale 1: 25.000) Dakhla Oasis had more than 2150 springs (A’yn) and wells or bir (see Fig. 25). More than 60% of these springs and wells have names. For toponymical analysis the current research classified these named springs into five classes: 1. Springs and wells have personal and family names (43% of the total number). 2. Flora and fauna related names (7%) where famous vegetation related names are Acacia, Willow, Doum Palm, Olive-tree, swamp sawgrass, and Heesh (Arundo). Brooks (1993) concluded that little remains of the natural vegetation, consisting of Sahelian, Sahara-Arabian, and Mediterranean floral elements, mixed with aliens introduced over −4000 years.

Fig. 22 Depression floor and scarp—West Mawhub area

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Fig. 23 Depression floor—Hindaw area

Fig. 24 Springs and wells in Dakhla Oasis

Springs and wells carry names of animals also give important indications about the environmental changes, the most famous names in this category are crocodile, gazelles, camel, wolf, cows, cats, beetles, etc. 3. Quality of water and size of spring are also obvious in toponymical analysis where 6% of the total springs and wells carry the names of cold water, hot water, yellowish, reddish, greenish, sweet water, brackish, etc. 4. Other toponymical classes includes geographic location related names (3%); settlement (3%); relief (2%); archeological and historical (6%) which carries names like roman spring, fort, Christian, monastery, etc.

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Fig. 25 Water well over old spring—from above the well into inner bottom

There is no active spring in Dakhla. The nearest one is in backward of Abu Tartur southern escarpment in Ain Amur, which lies in the geomorphic system of Kharga depression. With the expansion of land reclamation projects, recent deep wells have been drilled (see Fig. 26) while hundreds of natural springs are abandoned (see Fig. 27). Some karst landforms still active in the area, such as sinkholes in the playa floor (see Fig. 28). Among paleo springs there is an important landform: spring mound.

Fig. 26 Bir 3 in Rashda area, deeper than 700 m

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Fig. 27 Ancient spring—Balat area

According to Adelsberger (2008) spring mounds in Dakhla Oasis are found in the southern portion of the basin, associated with the contact between Taref Formation sandstones and Quseir Formation shales, as well as with faults and uplifted sandstone units associated with the Tawil Anticline. Spring mounds are small hillocks, mostly conical in shape. They range in height from a few to 20 cm. Each mound has a vent that is cylindrical and is surrounded by layers of clay, ocher (especially ferric oxides), sand or carbonates (see for more details Said 1980; Embabi 2018, p. 147). Adelsberger (2008) concluded that spring mounds occur as erosional remnants with variable thicknesses of Quaternary sediments; up to six meters of spring sediments may be preserved, but most mounds consist of only remnant silt overlying an erosional “mound” of Quseir Formation bedrock shale. Identifiable spring vents are often present, preserving iron oxide-stained silts and sands. Some preserved

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Fig. 28 Sinkhole, Sebkhas and old playa, south of Mut

mounds are capped by hard ironstone deposits. Paleogeographic models of paleolake formation in Dakhla have included spring mound development in connection with shallow-water or lake-margin (Adelsberger 2008).

3.3 Sand Dunes Dakhla Depression is surrounded by sand dunes and dune fields from nearly all directions. The sources of these dunes lies far north on the southern fringes of the Qattara Depression. From this context, Dakhla is an ideal “Oasis” since dunes are scattered around from many directions (see Embabi 1977, Gad 1992, Embabi 2004).

3.4 North: (El Dakar Dune Filed) From the northern direction, Libyan Plateau falls down the sand dunes across the escarpments. The cuesta-back of dipping northwestern-ward to Farafra depression gave a good chance to the drifting sands to accumulate in longitudinal dunes filed (Fig. 29). As this field has no name on the maps, I will name it “El-Dakar.” This

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Fig. 29 Longitudinal dunes of El-Dakar—Hishan area

name is used to the northern part of the dune field by native people in Farafra Oasis. “El-Dakar” means literally “male” or “man” a word used by Bedouin referring to “compacted” sand dunes easy to access by caravan or by the modern automobile. The other contrary word is “Nitaya” which is “female” or “woman” referring to soft friable sand dune non accessible for traveling because it usually humble the moving across. Dunes collapsing from El-Dakar through scarp into Dakhla Depression are diverged to eight arms.

3.5 West: (Great Sand Sea) The western part of Dakhla, beyond Edmonston detached hill, composed of semi compacted dunes and fringed from the western side by Great Sand Sea. This area of “Gharb El Mawhub” (West Mawhub) lies in the lee-ward of El-Dakar dune-field (see Fig. 30). The area in general devoid of mobile dunes as a result of lying in the shadow zone of drifting sands from upward tabular land, which is a clear model of “deflation surfaces.” The land reclamation project in “Gharb El Mawhub” could be extendable to 75 km west of Edmonstone, but beyond that the thick sand sheets and longitudinal dunes of Great Sand Sea humble any further effort. After this 75 km and for 90 km the asphaltic road faces the hazards of encroaching sand dunes till it reaches the small oasis of Abu Minqar. The encroaching sands from Great Sand Sea toward Gharb El

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Mawhub is a part of the vast area of longitudinal and inter-dunes corridors stretching westward for 290 km till the borderline with Libya and beyond.

3.6 East: (Dune Free-Zone) The eastern direction in Dakhla Depression is devoid of any dune fields or sand dunes. Thanks to Abu Tartur plateau, the extensive and very mobile of sand dunes lay far in northern Kharga depression, especially in the outskirts of Gebel El-Taref and Gebel El-Tir hills. Dunes in northern Kharga is the continuation of Gherd Abu Moharaq, which starts far north around Moghra depression and southeastern portion of Qattara Depression.

3.7 South To the south of the proper “oasis” extend the lee ward of the eight arms and vanish gradually in 80 km south of the depression. Some new small agricultural lands appeared at the expense of sand sheets south of Mut. The new asphaltic road to “East El Uwainat reclamation project” extends for 330 km from Mut southward straightforward; the only prominent landmark along this long road is the Six Hills topography on the mid-way (120 km south of Mut). This axis would be promising in land reclamation for agriculture in the foreseen future.

Fig. 30 Barchn dunes—south of Mawhub

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4 Conclusion and Recommendations The geomorphological study of Dakhla Depression gives some important remarks: 1. The importance of analyzing the landscape and landforms from a more wider view bridging the gap among the other geographic regions surrounded the area and located the correct place of Dakhla Depression in the wider image of Eastern Sahara. 2. The importance of multidisciplinary approaches to study Dakhla Depression from different specializations of earth sciences. 3. The study area undergoes different man-made hazards destroying its natural heritage in the land, water, and natural vegetation. There are many examples of problems of. 4. Over-irrigation and mismanagement of spring/well water resources. Most of land reclamation in the study area are going fast at the expense of playa, spring mounds, springs …etc. the last ten years were very dramatic in removing most of the quaternary natural history of the oasis. 5. Archaeological sites are suffering all kind of deteriorations, either by natural hazards or man-made ones (see Fig. 31). 6. Sand dunes in the study area are a very important issue to be monitoring in the future. There are new successful attempts to confront desertification in different parts of the depression (especially through cultivation) but dune fields still threatening the oasis very seriously. 7. Discharging drained water after cultivation is a big problem in many areas inside the depression. The triangle of Isment–Hindaw–Mut is a visible example for land salinization (see Fig. 32).

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Fig. 31 Sand encroaching Deir El Hagar Temple

Fig. 32 Mismanagement of water resources—Bir 3 area

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References Adelsberger K (2008) Geoarchaeology, geomorphology and sedimentology of paleolithic landscapes in Egypt. Unpublished Ph.D thesis. Washington University, Department of Earth and Planetary Sciences Aggour T, El Ghazawi M, Ghoubashi S (2012) Hydrological settings of the Nubian sandstone aquifer, El Zayat plain area, western desert, Egypt. Ann Geol Surv Egypt XXXI:41–56 Ashour M, Embabi N, Donner J, Abu Zeid K (2005) Geomorphology and quaternary geology of Abu El Egl Playa, Western Desert of Egypt. Bulletin de la Société de Géographie d’Egypte 78:1–27 Ball J (1942) Egypt in the classical geographers. Survey of Egypt, Cairo Brooks I (1993) Geomorphology and quaternary geology of the Dakhla oasis. Quat Sci Rev 12:529– 552 Donner J, Ashour M, Brook GA, Embabi N (2015) The quaternary history of Western desert of Egypt as recorded in the Abu El Egl Playa. Bulletin de la Société de Géographie d’Egypte 88:1–18 El Rasheidy E (2000) The geomorphology of Playa in Western Desert of Egypt. Unpublished Ph.D thesis, Ain Shams University El-Aref M, Abou Khadra A, Lotfy Z (1987) Karst topography and karstification processes in the Eocene limestone Plateau of El Bahariya oasis, Western Desert, Egypt. Zeitschrift fur Geomorphologie 31:45–64 Embabi N (1977) Slope form of barchan dunes at the Kharga and Dakhla depressions. Bulletin de la Société de Géographie d’Egypte. Tomes XLIX-L Embabi N (2004) The geomorphology of Egypt: Vol. 1, the Nile Valley and the Western Desert. The Egyptian Geographical Society, Cairo Embabi N (2018) Landscapes and landforms of Egypt. Springer Gad T (1992) Variables influencing the development of the Western Desert depressions in Egypt, with special reference to Dakhla and Kharga. Bulletin de la Société de Géographie d’Egypte. Tome LXV Haynes C (1984) Western Desert Quaternary studies, preliminary report on the 1984 field season. US Geological survey Issawi B, Francis M, Youssef E, Osman R (2009) The phanerozoic geology of Egypt: a geodynamic approach. Ministry of Petroleum, Cairo Issawi B, Youssef E (2016) Rejuvenation of old dry channels in NE Africa. Ann Geol Surv Egypt XXXIII:1–32 Moawad A. M, Raslan, Rashad, A (2008) Discovery of huge fossil vertebral Carcasses in the Dakhla formation near the K/T boundary, Dakhla Oases. Ann Geol Surv Egypt XXX:173–183 Mohamed A, Sultan M, Ahmed M, Yan E, Ahmed E (2016) Aquifer recharge, depletion, and connectivity: inferences from GRACE, land surface models, and geochemical and geophysical data. Geol Soc Am 129(5–6):534–546 Said R (1980) The quaternary sediments of the south western Desert of Egypt. In Wendorf F, Shield R (eds) Prehistory of the Eastern Sahara. Academic Press, New York Said R (ed) (1990) The geology of Egypt. Balkema, Rotterdam Said M, Oweiss K, El Mandi B, Sweisy K, Turki S, Diaf A, El Tagory A (1994) A note on the preliminary reconnaissance field trip to Al Uwaynat area. Ann Geol Surv Egypt XIX:549–569 Sallam H, Gorsak E, Lamanna M (2015) New Egyptian sauropod reveals late Cretaceous dinosaur dispersal between Europe and Africa. Nature, Ecology and Evolution

Archaeological Sites in Dakhla Oasis, Western Desert, Egypt Elsayed A. Zaghloul

Abstract In ancient times, since the last rainy season that prevailed in the region about 35,000 BC, there were fresh water lakes lived by the Stone Age man, with herds of cows, giraffes, and gazelles. The water springs were overflowing, and the oases continued until 9000 years ago when these lakes began to shrink and dry, leaving their sediments in what is known as the Playa deposits in the regions of Dakhla Oasis as well as other areas in the Western Desert. It has a continuity of settlements for about the last 8000 years, but only since 2500 BC, they moved to the Nile Valley but some settlements still exist around the natural springs and flowing water wells. Keywords Dakhla Oasis · Desert · Groundwater · Archaeology · Prehistory · National Park · Gilf Kebir · Rock art

1 Introduction The Oases of Egypt since ancient times were known as the “Oasis Bone” where it occupies a large depression in the desert and its capital Hibis, which derived its name from the word habbat meaning plough. During the Pharaonic times, the oases were of paramount importance because they were the first line of defense for ancient Egypt for exposure to attacks from the South and Libyans from the West. The Pharaohs were concerned about the calmness of the region and its stability for the abundance of its products.

E. A. Zaghloul (B) Geological Applications and Mineral Resources Division, National Authority for Remote Sensing and Space Sciences, 23 Joseph Tito Street, El-Nozha El-Gedida, Cairo, Egypt e-mail: [email protected]; [email protected] © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_5

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2 Archaeological Sites in Dakhla Oasis Dakhla Oasis is one of the most attractive cultural landscape. The Oasis is characterized by two main components as follows: (a) natural heritage component, and (b) cultural heritage component. The Playa deposits (Pluvial lakes) existed in the Western Desert during the Holocene, approximately 6000 years ago. These lakes controlling factor in the Neolithic occupation cores indicate a recent climatic episode more arid than fluctuations occurred in the recent past (Haynes et al. 1979). Mut is the capital of Dakhla Oasis (Fig. 1). This name derived from the death of the wife of the God Amun which was an ancient city during the Pharaonic times renown for the quality of their wine (Dakhleh Oasis Project et al. 2019). The most important archaeological sites are as follows.

Fig. 1 Location map of Dakhla Oasis (Zaghloul et. al. 2013)

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2.1 Deir al-Hagar Temple It is one of the most important temples in Dakhla, located about 47 km west of Mut. It dates back to the era of the Roman Emperors (Emperor Nero 54–68 CE). It is decorated with sandstone, and pictures and inscriptions on its walls representing the Pharaonic Creed. It was built to worship the God Amun. It was called a stag meaning “the Land of the Moon”. The site is surrounded by a wall designed to protect it from the sand dune encroachments (Zaghloul 1999). The temple consists of a two-column court and a court of Hepostil with four columns, a vestibule and a sanctuary. Each column (Fig. 2) is located in the Hippostyle Hall with inscriptions belonging to Emperor Titus. There are some interesting basic inscriptions representing religious life. The effects of the painting are visible with some Coptic writings, a clear indication that the temple was later used as a church (Figs. 2 and 3).

Fig. 2 Plan of the Deir al-Hagar Temple (Kaper and Klaas1999)

Fig. 3 a and b General view of the temple Taken by the author

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2.2 Deir al-Hagar Ancient Water Supply System Archaeological investigation had identified evidence of irrigation in Mesopotamia and Egypt as far back as the 6th millennium BC when barley was grown in areas where the natural rainfall was insufficient to support such a crop. Zaghloul et al. (2013) used the term Ancient Irrigation Canals to describe these canals. In the present work, the author prefers to use the term Ancient Water Supply System which represents how people bring the water from the natural flowing spring in the south for the irrigation and domestic use in the settlement around Deir al-Hagar Temple. Using satellite image (Egyptsat-1), it is easy to trace and to detect these canals from the natural spring (Fig. 4). These canals are the earliest record of the water supply system in the period of Neolithic II. Large scale agriculture was practiced, and an extensive network of canals was used for irrigation (Fig. 4). The system comprises a network of canals gently sloping northward driven by the water from the natural artesian springs into the deflated surface of the playa (Fig. 5). Most of this system still exist undamaged up to now and filled by the drift of aeolian sand. The length of the main canal varies from 2265.5 m. to 2740 m. while the width varies from 4.5 m. to 14.30 m.

Fig. 4 Enhanced derivative Egyptsat-1 image showing the location of the temple and the traces of the ancient irrigation canals (after Zaghloul et al. 2013)

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Fig. 5 Field photo showing traces of the ancient irrigation canals dissected the surface of the Playa (after Zaghloul et al. 2013)

The sand dune encroachments and the lowering of the groundwater level due to the climatic changes and the over extraction of the shallow groundwater aquifer caused the groundwater depletion and detorioration.

2.3 Qaret al-Muzawaka Tombs It is located about 5 km west of Qasr Village and about 37 km from Mut city. It is a cemetery dating back to the Roman era and was discovered by the Egyptian archaeologist Ahmed Fakhri in 1937 (Fakhry 1974). It contains tombs carved in rock (Fig. 6) and has a bright inscription representing the oasis and the cultivation of barley, palms, birds, embalming, arithmetic and punishment. its name is attributed to the abundance of colors and clarity and decorations (Fig. 7).

2.4 Al-Qasr Islamic Village Al-Qasr (Palace in Arabic) Village is considered as one of the most important Islamic archaeological sites in the New Valley Governorate. It is located 22 km north west of Mut. It was the first village to receive the Islamic tribes in the oases in the year

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Fig. 6 Qaret al-Muzawaka tombs Taken by the author

Fig. 7 Color paintings on the walls of Qaret al-Muzawaka tombs https://www.flickr.com

50 AH and the remains of a mosque from the first century AH and flourished in the Ayyubi era. The village was the capital of the oasis and the Palace of the Governor and one of the entrances of the old Islamic Fort dated back to the Ayyubi era. It has a wooden minaret (Fig. 8) consisting of three floors at the height of 21 meters, and there are wooden thresholds inscribed with Quranic verses. The Islamic school and Al-Sheikh Nasr al-Din Mosque is one of the oldest mosques, and is an ancient building built of mud bricks. The visitors are impressed by the magnificence of the

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Fig. 8 Minaret of Ayyubi Mosques https://www.flickr. com

planning of buildings in the Islamic Palace in terms of organization, construction, and planning of the Islamic cities at that time. The temperature in the old palace is kept at less than 13 degrees Celsius, which shows the greatness and ability of the inhabitants of this village. There are also several mosques of the Turkish and Mamluk era, and there is a temple gate for the God Thoth which is used as an entrance to a house. Unfortunately, the encroachment of concrete and recent buildings led to the disappearance of what people can see from outside the village (Fig. 9).

Fig. 9 General View of Al-Qasr https://www.flickr.com

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2.5 Darb al-Ghabari Inscriptions On the entrance to the Dakhla Oasis where sandstone blocks take many forms, some rock art painting (rock inscriptions) from the prehistoric man since about 5000 BC were recorded. The human drawings are depicted after the introduction of agriculture and grazing depicting the palm and the animals.

2.6 Bashandi Village It is a small village built in Pharaonic style by green bricks. An ancient temple buried in the sand is likely to be from the 19th Dynasty and then was restored in the region of Ramses IX. There are also a Roman cemetery of the rulers of this region since the first century AD. In the south of the village is a temple in the spring of the Roman era and built of sandstone. In the village, there is an Islamic Cemetery of Sheikh Bashandi, after whom the village was named. He was the village leader in the Turkish era. His tomb was built of ancient Pharaonic temple stones that were used in the village and were used as a prayer site.

2.7 Balat Village It is located above a high hill. Its streets are narrow and domed of palm wood and palm trees and divided into the streets of families with wooden inscriptions on their gates, specifying the family name, the date of construction and the verses of the Holy Quran.

2.8 The Pharaonic Tombs in Balat At the distance of one kilometer from the Balat Village, where there are five terraces made of mud brick above each other, such as the Pharaonic tombs next to other Roman tombs, as well as the gate of the tomb of the governor of the area headed by two small animals and a door line Hieroglyphs refers to the era of the ancient state VIth Dynasty 2430 BC. This is evidenced by the fact that the area of Balat was the center of the oasis in the Pharaonic times and was where the royal court was established in the era of Kings Papy I and II.

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3 Gilf Kebir Area Gilf Kebir is a huge massif plateau located 150 km north of Gabal Uweinat, rising 300 m above the desert floor and reaching almost 1100 m asl. It is on the border between the Western Desert of Egypt and the Libyan Desert, The plateau disappears into the Great Sand Sea (Fig. 10) to the north. In the following subsections, a brief description of some areas will be given.

3.1 Abu Ballas Area During his trip from Dakhla Oasis to Gilf Kebir Plateau, Ball (1927) discovered over one hundred big jars located in a remote area south of Dakhla Oasis. It is located about 70 km on the road to the east of Uweinat project and then the deviation westward for a distance of 180 km towards the plateau. This area was served as a station or point of concentration for groups of invaders or thieves who come from Kufra Oasis in Libya, seeking the looted oases of looting and robbery. In the absence of drinking water in the distance from Kufra to Dakhla, these invaders used this area to leave pottery vessels filled with water in a big vessel called Ballas in their journey back and forth from to supply water in the middle of the road to ensure their drinking water in the desert. As usual, the invaders came from Libya to Dakhla, followed by one of the citizens from Dakhla Oasis who knew the secret of Abu Ballas. A number of the inhabitants went out from Dakhla to break the pottery vessels (Fig. 11), and poured the water on the ground. However, some authors dated the pottery materials to the Late Predynastic or Early Dynastic period, Ramesside Dynasty of the 12th-century BC (Förster and Kuper 2003; Förster 2007a, b). Pharaonic influence can also be detected in two rock engravings below the top of the hill, which were discovered by Prince Kemal el Din in 1924 and later recorded by Hans Rhotert (1952; Kaper and Klaas 1999). According to the observations by Prince Kemal el Din, Rhotert and Kuper, Abu Ballas could be the last station of Persian King Cambyses II who is said to be buried with his army in the Great Sand Sea in the sixth century BC after he attacked Siwa from Thebes (Luxor) where Temple of Amun was burned and destroyed to avenge the priests. Cambyses II marched at the head of an army of fifty thousand fighters, and arrived Kharga Oasis in ten days. Herodotus said that they were misled by the commanders of the exiles to the sand sea, where the sand storm that lasted for several days swallowed the army in the sand sea. The storm did not subside until the whole army settled in the sand sea between the exodus and Siwa.

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Fig. 10 Map showing the prominent landscape features in Gilf Kebir Courtesy of A. Siliotti— Geodia

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Fig. 11 Remains of pottery vessels (Balas) that were broken and destroyed https:// en.wikipedia.org/wiki/Abu Ballas

3.2 The Rock Art Inscriptions The surface of Gilf Kebir plateau is dissected by deep canyons which are the principal drainage lines collecting and channeling all run-off from the plateau surface north- and eastward into the plains. These valleys often have a gorge-like shape with steep high reaching walls and cliffs mainly made of sand stone. As for plant and wildlife resources, the most relevant valley systems are Wadi Abd al-Malik, Wadi Hamra, Wadi Assib, Wadi Talh, and Wadi Sura (in Arabic meaning picture). Most probably that Gilf Kebir—Uweinat region is characterized ecologically as a transition zone between savannah in the south and desert in the north in the past times before the climate change. Rock carvings and rock art paintings were discovered by Almásy (1999). The stunning depictions of people who look like they are swimming—known as the Cave of Swimmers (23˚ 35´ 40.99˝ N–25˚ 14´ 0.60˝ E)—and of abundant wildlife, including giraffes, sheep, cattles and hippopotamuses, are probably around 10,000 years old (Neolithic Time). Almásy (1999) suggested that the swimming indicates the paleoclimate and paleoenvironment during the Neolithic time in these now dry and barren areas. The area includes more than two thousand images of inscriptions and drawings of the first human, as well as many of the Pharaonic monuments and drawings of prehistoric (Fig. 12). There are dozens of caves in the region talking about the area when it belonged to a different climate where it witnessed a rainy era, which led to the presence of grass, trees and lakes.

3.3 Gilf Kebir National Park (GKNP) The region was declared a protected area in 2007. It extends over 47,940 km2 of the Western Desert (NCS and EEAA 2007), which represents almost 5% of Egypt’s surface area. The park includes a unique cultural, environmental and natural heritage (Geo-heritage) of international importance.

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Fig. 12 A side of the rock inscriptions in the caves of the valley and the cave of the swimmers (Almásy 1999)

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Fig. 13 Silica Glass Microlithic Core (NCS/EEAA 2007)

3.4 The Silica Glass Area The silica, or desert glass, was discovered by Clayton as a rare phenomenon in the world (Clayton 1937). It is a piece that varies in color, clarity and size distributed over an area approximately 130 km long by 50 km wide to the north of Gilf Kebir and closed to the western edge of the Great Sand Sea. It is believed to have formed from a meteoric shock that hit a region called the “Al-Hish” about 27 million years ago when the meteor collided with the sand creating a very high temperature that led to smelting the sand and turning it into glass (Fig. 13). Silica glass was used by prehistoric man and was known to the ancient Egyptians.

4 Conclusion The archaeological sites in Dakhla Oasis region provide examples of the alternating wet and dry climate phases in the shaping of oasis landscapes, ancient civilizations and climate the changes. It exemplifies the complexity of the water/life relationship in a spring-mound fed oasis with groundwater and distances itself from the mechanistic logic of “hydraulic fixes” in Deir al-Hagar area and the surface water as in the active wadis and lakes as in Gilf Kebir wadis. Tourism in Dakhla Oasis is still minimal compared with the rest of Egypt which has helped to continue to preserve its heritage. The urban encroachments in the oases

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had disastrous effects upon the archaeological sites and cities. As far as Dakhla Oasis is rich in many archaeological sites from prehistoric to recent times, landscape and natural resources, special attention should be addressed for the development of these resources for ecotourism and desert safari. It contains vast, remote areas that are hard to access and needs a good management plan for the conservation and protection of these resources for the future generations and researchers.

5 Recommendations The management of the archaeological areas in the Dakhla Oasis region will require good information obtained from monitoring and research. The following concern should be taken into consideration. – Using the Laser scanning techniques for the documentation of the archaeological sites for recording and presentation and the digital media (Visual tour/ Visual reality). – Information, education and public awareness are the most helpful tools for the conservation and the protection of such resources. – The collection or disturbance of Neolithic artifacts and the damage of the rock art sites by visitors are serious problems and prohibited by the Antiquities Law 117 of year 1983. – Minimal infrastructure interventions will be permitted inside the Gilf Kebir National Park. – Ensuring visitor management and safety in remote areas through a special office in Mut City.

References Almásy LE (1999) Schwimmer in der Wüste. Auf der Suche nach der Oase Zarzura. München: Deutscher Taschenbuch Verlag 2, 11 Ball J (1927) Problems of the Libyan desert. Geogr J 70:2–38, 105–128, 209–224 Clayton PA (1937) The South-Western desert survey expedition 1930–1931. Bull de la soc roy de géographie d’Egypte XIX(3):241–265 Fakhry A (1974) The oases of Egypt, vol 2. Bahriyah and Farafra Oases, Cairo Förster F, Kuper R (2003) Abu Ballas (Pottery Hill): Call for information. Sahara 14:167–168 Förster F (2007a) The Abu Ballas trail in the late Old Kingdom: a Pharaonic donkey caravan route in the Libyan Desert (SW Egypt). In: Bubenzer O, Bolten A, Darius F (eds) Atlas of cultural and environmental change in Arid Africa. Africa Praehistorica 21 (Köln: Heinrich-Barth-Institut), pp 130–133 Förster F (2007b) With donkeys, jars and water bags into the Libyan Desert: The Abu Ballas trail in the late Old Kingdom/First Intermediate Period. BMAES 7 Haynes V, Mehringer P, Zaghloul EA (1979) Pluvial lakes of North-Western Sudan. Geogr J 145(3):437–445

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Kaper OE, Klaas A (1999) Worp Dipinti on the temenos wall at Deir el-Haggar (Dakhla Oasis). BIFAO, 233–258 Kuper R (1999) The Abu Ballas trail: Pharaonic advances into the Libyan Desert. In: Hawass Z, Pinch Brock L (eds) Egyptology at the dawn of the twenty-first century: Proceedings of the Eighth International Congress of Egyptologists, Cairo 2000, vol 2: History, Religion. Cairo, New York: American University in Cairo Press, pp 372–376 Dakhleh Oasis Project, Bowen GE, Colin AH (2019) The Oasis papers 9: a tribute to Anthony J. Mills after forty years of research in Dakhleh Oasis: proceedings of the ninth International Conference of the Dakhleh Oasis Project. http://search.ebscohost.com/login.aspx?direct=true& scope=site&db=nlebk&db=nlabk&AN=2332847 Nature Conservation Sector (NCS), Egyptian Environmental Affairs Agency (EEAA) (2007) A concise report on the expedition to the Gilf Kebir National Park. Nature Conservation Sector, Egyptian Environmental Affairs Agency. Nature Conservation Capacity Building Project, Cairo Rhotert H (1952) Libysche Felsbilder. Ergebnisse der XI. und XII. Deutschen Inner–Afrikanischen Forschungs–Expedition (DIAFE) 1933/1934/1935. L. C. Wittich, Darmstadt Zaghloul EA (1999) Geo-archaeology and hydrogeology of Deir El-Hagar playa. Dakhla Bull Soc Geogr Egypt LXXII(72):81–90 Zaghloul EA, Hassan SM, Bahy El-Dein AM, Elbeih SF (2013) Detection of ancient irrigation canals of Deir El-Hagar playa, Dakhla Oasis, Egypt, using Egyptsat-1 data. Egypt J Remote Sens and Space Sci. 16(2):153–161

Climate Features of Dakhla Oasis Reiji Kimura

Abstract The Dakhla Oasis climate is predominantly controlled by a dry wind that blows hot air from the Sahara at subtropical high pressures, which causes an oasis effect. Therefore, the characteristics of the Dakhla Oasis climate are typical for both desert and oasis. This chapter describes these climatic features, which are explained using synoptic meteorological data from 2007 to 2016. Climate differences between the Dakhla and Kharga oases are also briefly discussed. Recommendations for use of improved remote-sensing resources to monitor climate in this area are also presented. Keywords Dakhla Oasis · Climate · Oasis effect · Arid regions

1 Introduction Crop production is largely related to the Nile River in Egypt (Kato et al. 2010; Kimura et al. 2020). Vegetation grows primarily in the Nile delta region, whereas very little vegetation is observed far from the Nile River because of Egypt’s hyper-arid climate. There are areas, however, where vegetation is found far from the Nile. The amount of vegetation growing in these oases is small, but they have long been part of the desert landscape (Kimura et al. 2015). Cultivation in oasis areas is highly dependent on artesian groundwater originating from the Nubian aquifer (Dabous and Osmond 2001). Although the amount of groundwater resources is very large, the water is not rechargeable because of little rainfall. Wells are therefore dried up in the future. Groundwater tables differ due to geological features. Wells are developed as previous wells are not used. Therefore, crop production in oasis regions is unstable from a sustainable water use perspective (Kimura et al. 2015). Dakhla is in the middle of Egypt, that is, southwest of capital Cairo (Kimura et al. 2015). The Dakhla depression extends about 155 km in an east-west direction. The land is very fertile and rich in water—the suitable agricultural area is about 155 km R. Kimura (B) Arid Land Research Center, Tottori University, 1390 Hamasaka, Tottori 680-0001, Japan e-mail: [email protected] © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_6

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by 60 km. Irrigation farming has recently extended, and the number of wells in 2012 had increased by about 30% from that in 2008. Efficient irrigation farming is crucial to establish the sustainable water use (Kato et al. 2010). This chapter focuses on climate features of Dakhla Oasis, which are important factors to consider when evaluating the sustainable water use in oasis regions. First, the climate history of the Western Desert of Egypt is presented, followed by a description of current conditions. These climatic features are then examined by using synoptic meteorological data from 2007 to 2016, and the climatic differences between Dakhla and Kharga Oases are discussed. Recommendations for use of improved remote-sensing resources to monitor climate in this area are also presented.

2 Climatic History of the Western Desert of Egypt About 20,000 years ago, during the coldest period of the last ice age, the monsoon season weakened in the tropical area, which facilitated a dry climate. Tropical Africa also experienced a largely dry climate, and the boundary of the Sahara was several hundred kilometers south of its present location. The desert spread into the tropical area during this era (Shinoda 2002). Geological, archaeological, and paleoclimatic reconstructions indicate that the eastern Saharan climate during the early-to-mid Holocene (9,300–4,500 years BP) was much wetter than it is today (Salman et al. 2010) because an intertropical convergence zone (ITCZ) existed farther north as compared with the present day. The ITCZ is a belt of converging trade winds and rising air that encircles the Earth near the equator and produces heavy rainfall. Strong monsoons from the Indian and Atlantic oceans contribute a large quantity of water vapor that was transported to the Saharan ITCZ. In addition, the transpiration of Saharan vegetation actively supplied even more water vapor to the atmosphere. The Saharan climate had wet peaks from 9,000 to 8,000 and from 7,000 to 5,000 years ago. During these periods, there was a large amount of rainfall in the Sahara, which was covered by savanna and steppe vegetation. These wet phases were characterized by the rapid onset of a mosaic of freshwater lake and swamp formations, which led to groundwater recharge of the Nubian aquifer in the eastern Sahara Desert (Pachur and Hoelzmann 2000). The Dakhla Oasis region was also once dominated by a vast lake. Neolithic rock carvings indicate that various animals, including elephants, zebras, and giraffes, occupied its shores. During these periods, the oasis would have been similar to the African savanna (https://egyptsites.wordpr ess.com/2009/03/10/introduction-to-dakhla-oasis/). A humid period (the Green Sahara era) in tropical Africa around the Sahara to Sahel regions ended about 4,500 years ago, when climate cooling began on a global scale. Since then, minor wet and dry periods have cycled, with the present cycle representing a drier period. From a long-term perspective, the present Sahara, including Dakhla Oasis, is in the middle of an aridification period (Shinoda 2002). Based on analyses of fossil diatoms in Lake Qarun, Egypt, there was a sudden change

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in the climatic environment in the upper reaches of the Nile around 3,500 BC, 2,000 BC, 200 BC, AD 450, AD 1,000, and AD 1,700 (Shinoda 2009). The natural vegetation of the current Sahara is uncommon to the African region, but shares deep commonalities with the central Eurasian Continent. Thus, the biology in the Sahara Desert completed the process of differentiation relative to the arid regions from central Eurasia to northern Africa during the Tertiary to Quaternary eras (Mizuno 2005).

3 Overview of the Climate in Egypt Today The current Egyptian climate is featured by a hot (March to September) and cold seasons (October to February), although the northerly prevailing winds called Harmattan keep temperatures relatively moderate. In the coastal regions along the Red and Mediterranean seas, the average annual temperatures range from 14 °C to 37 °C. The wettest area is along the Mediterranean coast, where the average annual rainfall is about 200 mm. Rainfall decreases drastically towards the south where it might rain only once every several years in many desert areas (Robaa 2008). Temperatures change largely in the desert regions. In the summer, the diurnal range is from 7 °C at night to 43 °C at daytime. Temperatures fluctuate less in winter, but they are still be from 0 °C at night to 18 °C at daytime (Robaa 2008). Annual temperature increases southward from the Nile Delta to the Sudanese border (Metz 1990: http:// countrystudies.us/egypt/53.htm). The solar radiation is 12 to 30 MJ/m2 /day, and the sunshine duration is from 3500 to 4500 h/year (Tadros 2000). Egypt is featured by fine skies during the summer (June to August) and partly cloudy skies during the spring (March to May) and autumn (September to November) (Robaa 2008). In the winter, Egypt is featured by cloudy skies, but cloud cover decreases from north to south. Hot springs winds, known to Egyptians as the Khamsin wind and to Europeans as the Sirocco wind, characteristically blow across the country. Khamsin arrive in April, but sometimes occur in March or May (Robaa 2008). Because of the lack of geographical features to obstruct them, the winds reach high velocities (up to 39 m/s from the south or southeast) and transport great deal of sand or dust from the deserts. These sand or dust storms cause temperatures to increase by 20 °C in as little as 2 h. The winds can continue for days, and cause health problems for both human and animals (Robaa 2008).

4 Climatic Characteristics of Dakhla Oasis Climate in Dakhla Oasis is under the control of the Harmattan dry wind, which is a dry wind (6–14 m/s) that blows hot air from the Sahara due to a subtropical high pressure center called the “Azores High,” causing an oasis effect. Thus, the Dakhla Oasis climate has characteristics that are typical of both desert and oasis, including:

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• Fine weather, high evapotranspiration demand, and nearly zero annual rainfall; • A short season for hot weather human activity, from May to September; • Sand storms and/or dust events can occur throughout the season, but are less frequent compared with Kharga Oasis 120 km to the east; • Humidity is high relative to typical arid regions; • Temperature, wind speed, and potential evapotranspiration are lower compared with Kharga Oasis. Herein, these climatic features are explained using synoptic meteorological data from 2007 to 2016. These data were downloaded from the National Climatic Data Center (https://www.ncdc.noaa.gov/). However, because solar radiation data cannot be observed at the Dakhla meteorological station, sunshine data from 2008 to 2010 collected from Kharga Oasis (120 km east of Dakhla Oasis) were used in the sunshine duration analysis (note that there was a high proportion of missing data and no observations since 2011).

4.1 Sunshine Duration, Precipitation, and Aridity Data for these analyses were collected from two meteorological stations: the Dakhla meteorological station, located at 25.5°N latitude and 28.967°E longitude at an elevation of 117 m, and the Kharga station, located at 25.45 °N latitude and 30.533 °E longitude at an elevation of 73 m. From 1990 to 2005, the relative sunshine duration (defined as the percent of actual sunshine duration out of the possible sunshine duration) averaged 87% (from a low of 82% in January to a high of 90% during June to August) at the Kharga station (Robaa 2008). The highest amount of solar radiation in the world occurs around the southwestern desert of Egypt (Budyco 1956). More recent relative sunshine duration data from the Kharga meteorological station (2008–2010) reveal similarly high rates of sunshine duration as well as high rates of solar radiation (Table 1). Annual precipitation was 0 mm from 2007 to 2016, except for 72 mm of rainfall on 1 December 2016. The Dakhla Oasis climate is controlled by high-pressure weather patterns; therefore, apart from the ITCZ, few factors contribute to rain formation. The aridity index (AI) defined by the United Nations Environment Program (UNEP 1997) shows that this region is in a hyper-arid. Herein, AI is defined as the ratio of annual rainfall to potential evapotranspiration (ETp ), where ETp is the amount of water that would be removed from the land surface by evaporation and transpiration if the amount of water already present in the land surface were not a limiting factor. Thus, ETp can be determined only based on climatic demand. Annual and monthly values of ETp were derived from meteorological data from the Dakhla and Kharga stations by using the FAO Penman–Monteith method (Allen et al. 1998). The average annual ETp was calculated to be 1781 mm, with monthly totals from May to August exceeding 200 mm (Fig. 1). As a point of comparison, in Tottori, Japan, where the annual rainfall is 2000 mm/year, ETp is 700 mm/year, or less than

Climate Features of Dakhla Oasis Table 1 Relative sunshine duration and daily average solar radiation averaged from 2008 to 2010 in Kharga meteorological station

93 Relative sunshine duration (%)

Daily average solar radiation (MJ/m2 )

January

85

15.0

February

90

18.6

March

84

21.6

April

79

24.3

May

81

25.8

June

88

27.2

July

88

26.7

August

91

25.1

September

88

22.9

October

89

18.9

November

93

15.9

December

88

14.2

300 266 250

250

ETp (mm/month)

206

200

259

Dakhla 243

215

222 206

200

Kharga 216

177 163

150

181

166 142

134

116

100

84

105 89

91

71

87 70

50

0 1

2

3

4

5

6

7

8

9

10

11

12

Month Fig. 1 Monthly potential evapotranspiration averaged from 2007 to 2016 calculated with data from Dakhla and Kharga meteorological station

40% of that in Dakhla Oasis. Because ETp is so high in Dakhla, the areas around the oasis are less in with little soil moisture (Brookes 2001). A maximum ETp of about 2500 mm/y was estimated for North Africa, so the ETp in Dakhla was relatively low in comparison. This may indicate that the vapor pressure is comparatively high and the temperature low because of the oasis farming effect.

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4.2 Temperature The annual average, average maximum, and average minimum temperatures from 2007 to 2016 at Dakhla were 24.4, 32.9, and 15.9 °C, respectively (Fig. 2). The daily maximum and minimum temperatures were 42.5 and 4.4 °C, respectively. The diurnal temperature amplitude averaged 16.9 °C, with an average maximum of 21.2 °C and an average minimum of 12.4 °C. Seasonal variation in daily temperature is small from June to August and large during other periods, especially March to May when the Khamsin wind prevails. The temperature was never below 0 °C. Dakhla’s temperatures are typical of a desert climate, including the large diurnal amplitude, but it is not too severe for human activity. The comfortable season for human activity is comparatively long, from October to April, based on a discomfort index calculated from monthly maximum daily averaged temperature and humidity (Fig. 3). For agriculture, the ETp demands during the summer are large (Fig. 1); therefore, cultivation during winter makes sense from a water-conservation perspective. It is interesting to note that the period most comfortable for humans nearly coincides with the winter agricultural production period. However, because and temperature is sufficient for agriculture, cultivation with relatively little or no rainfall depends on the availability of groundwater in Dakhla Oasis, even during the summer. Wet rice farming is conducted once every few years. 45 40

Temperature (Υ)

35 30 25 20 15 10

Daily average Daily maximum Daily minimum

5 0

1

31

61

91

121

151

181

211

241

271

301

331

361

Day of year Fig. 2 Seasonal change of daily average, maximum, and minimum temperatures averaged from 2007 to 2016 in Dakhla Oasis. Some parts are modified after Kimura et al. (2020)

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Fig. 3 The relationship between monthly averaged humidity and monthly maximum daily averaged temperature (average from 2007 to 2016) in each month in Dakhla Oasis

4.3 Wind Conditions The wind conditions in Dakhla Oasis are controlled by the Harmattan wind, so the wind direction is almost always due north except during the Khamsin wind. Although the wind is nearly always northerly (Brookes 2001). The wind speed is comparatively calm under the effect of high pressure: i.e., annual average was 1.9 m/s, and average maximum wind speed was 3.9 m/s in Dakhla (from 2007 to 2016). However, on some days the maximum wind speed exceeds the threshold wind speed for dust outbreak, as shown in Fig. 4 for 2016. If the threshold wind speed for dust emission is 6.5 m/s (Tegen and Fung 1994), there is the potential for dust emissions throughout the year, especially during the Khamsin period (from DOY 61 to 121). In addition, a wind speed over 6.5 m/s usually causes degradation in visibility. Strong winds may be caused by the development of a mixing layer specific to the desert climate during the spring season in addition to during the Khamsin. For comparison purposes, the wind conditions in Kharga Oasis are also shown in Fig. 4.

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Threshold for dust outbreak (6.5 m/s)

Fig. 4 Seasonal change of daily average, maximum, and visibility in 2016 of Dakhla and Kharga. Some parts are modified after Kimura et al. (2020)

There are notable differences in the number of days with winds over 6.5 m/s and visibility degradation between the two oases.

4.4 Humidity A distinctive climate forms in an oasis as compared with the desert in terms of humidity. The annual average relative humidity and vapor pressure in Dakhla (from 2007 to 2016) were 33% and 11 hPa, respectively (Fig. 5). As a reference, the annual average vapor pressure is 6.7 hPa in the semiarid Loess Plateau in China (with annual precipitation of 350 mm) and 13.5 hPa in humid Tottori (annual precipitation of 2000 mm). Therefore, the Dakhla Oasis climate can be considered to be humid. The combination of a comparatively high humidity, calm wind speed, and low temperature causes a low evapotranspiration demand and saves irrigation water, as discussed in the next section.

97

60

1.6

55

1.4

50

1.2

45

1

40

0.8

35

0.6

30

0.4 Humidity

25

Vapor pressure (kPa)

Humidity (%)

Climate Features of Dakhla Oasis

0.2

Vapor pressure

20

0 1

31

61

91

121 151 181 211 241 271 301 331 361

Day of year Fig. 5 Seasonal change of daily averaged humidity and vapor pressure averaged from 2007 to 2016 in Dakhla Oasis. Some parts are modified after Kimura et al. (2020)

4.5 Climatic Differences Between the Dakhla and Kharga Oases The values for various climate factors in the Dakhla and Kharga Oases for 2007 to 2016 are presented in Table 2. The temperature, wind speed, and ETp were lower in Dakhla Oasis, as compared with Kharga Oasis. Of particular note, the ETp in Dakhla Oasis was about 400 mm (1.1 mm/day) lower compared with that in Kharga Oasis, which means that the evapotranspiration demand is low and that relatively more irrigation water can be saved for plant production in Dakhla Oasis. Table 2 Climatic differences between Dakhla and Kharga Oasis using the data from 2007 to 2016

Dakhla

Kharga

Tavg(°C)

24.4

25.9

Tmax(°C)

32.9

33.4

Tmin(°C)

15.9

17.8

Hu (%)

33.0

33.7

e (hPa)

11.0

11.0

Uavg (m/s)

1.9

3.0

Umax (m/s)

3.9

ETp (mm)

1781

5.4 2177

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5 Conclusions This chapter described climatic features in Dakhla Oasis and some climatic differences between Dakhla and Kharga Oases. The main findings are as follows: • Relative sunshine duration is generally very high, and annual precipitation is close to 0 mm, with few exceptions. • The aridity index AI (annual rainfall to potential evapotranspiration), used by the UNEP (1997), indicated that this district lies in a hyper-arid region. • The annual average, average maximum, and average minimum temperatures (2007–2016) in Dakhla were 24.4, 32.9, and 15.9 °C, respectively. The daily maximum and minimum temperatures were 42.5 and 4.4 °C, respectively. The average diurnal amplitude was 16.9 °C, the maximum was 21.2 °C, and the minimum was 12.4 °C. • Wind speed is comparatively calm under the effects of high pressure. The annual average relative humidity and vapor pressure (from 2007 to 2016) were 33% and 11 hPa, respectively. The comparatively high humidity, calm wind speed, and low temperature cause a low evapotranspiration demand and can result in the conservation of irrigation water. • Temperature, wind speed, and annual ETp are lower in Dakhla Oasis as compared with Kharga Oasis. Annual ETp in Dakhla Oasis is about 400 mm (1.1 mm/day) lower than it is in Kharga Oasis.

6 Recommendations • In this study, climate features of Dakhla Oasis were evaluated by using synoptic meteorological data. These data have been accumulated continuously, so they are valuable to monitor climate changes, for example, global warming. However, additional meteorological stations are needed to manage irrigation water use in oasis regions because local climate conditions differ, often as a result of local geographic features. • Use of satellite data may support efforts to monitor local climate conditions. Satellite sensors such as the Moderate Resolution Imaging Spectroradiometer (MODIS) can be used to monitor land surface temperature, vegetation indices, evapotranspiration, and other important factors. Newer systems, such as the Second Generation Global Imager (SGLI) sensor on the Global Change Observation Mission (Climate) satellite have a higher resolution (250 m) than MODIS, and many kinds of channels and products. These satellite data can be used to cover for the shortage of meteorological stations in Oasis regions.

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References Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration: guidelines for computing crop water requirements. FAO, Rome, p 300 Brookes IA (2001) Aeolian erosional lineations in the Libyan Desert, Dakhla region. Egypt Geomorphology 39:189–209 Budyco MI (1956) Heat balance of the earth’s surface. Seizando, Tokyo, p 271 Dabous AA, Osmond JK (2001) Uranium isotopic study of artesian and pluvial contributions to the Nubian Aquifer, Western Desert. Egypt J hydrol 243:242–253 Kato H, Iwasaki E, Nagasawa E, Anyoji H, Matsuoka N, Kimura R (2010) Rashda: system of irrigation and cultivation in a village in Dakhla Oasis. Mediterr World 20:1–45 Kimura R, Kato H, Iwasaki E (2015) Cultivation features using meteorological and satellite data from 2001 to 2010 in Dakhla Oasis. Egypt J Water Resour prot 7:209–218 Kimura R, Iwasaki E, Matsuoka N (2020) Analysis of the recent agricultural situation of Dakhla Oasis, Egypt, using meteorological and satellite data. Remote Sens 12:1264 Metz HC (ed) (1990) Egypt: a country study. GPO for the Library of Congress, Washington, p 428 Mizuno K (2005) Nature in Africa. Kokon Shoin, Tokyo, p 257 Pachur HJ, Hoelzmann P (2000) Late quaternary palaeoecology and palaeoclimates of the eastern Sahara. J Afr Earth Sci 30:929–939 Robaa SM (2008) Evaluation of sunshine duration from cloud data in Egypt. Energy 33:785–795 Salman AB, Howari FM, El-Sankary MM, Wali AM, Saleh MM (2010) Environmental impact and natural hazards on Kharga Oasis monumental sites, Western Desert of Egypt. J Afr Earth Sci 58:341–353 Shinoda M (2002) Desert climate. Seizando, Tokyo, p 169 Shinoda M (2009) Nature in arid region. Kokon Shoin, Tokyo, p 213 Tadros MTY (2000) Uses of sunshine duration to estimate the global solar radiation over eight meteorological stations in Egypt. Renew energy 21:231–246 Tegen I, Fung I (1994) Modeling of mineral dust in the atmosphere: Sources, transport, and optical thickness. J Geophy Res 99:22897–22914 UNEP (1997) World Atlas of desertification. Arnold, London, pp 1–182

Land Use, Soil and Cultivation

Aeolian Sand Transport Potential and Its Environmental Impact in Dakhla Oasis, Egypt Abbas M. Sharaky

Abstract Sand dune encroachment is one of the most environmental issues in Africa. It is a natural cause of desertification in the Western Desert, Egypt. The arid lands in Africa are strongly influenced by desertification. Sand dune movements threaten irrigated lands and water canals, residential areas, and water wells Dakhla Oasis. Sand dunes in Dakhla Oasis are crescentic and linear dunes. Several villages in Dakhla suffer from dune encroachment. The rate of Dakhla dune movement was measured using two sets of aerial photographs, 1961 and 1982 and Landsat images 2019. The rate of sand dune movement is between 0.5 and 14.0 m/yr with an average of 5.8 m/year for the crescentic dunes. That of liner or longitudinal dune (Seif) movement is 7.5 m/year. Sand dune movements are determined by dune size and local wind direction and velocity. Small dunes generally move faster than the larger ones. The rates of crescentic dune growth in terms of width and length average between 25 and 37 cm/year. The present chapter applied Sand drift potential (DP) formula using Fryberger model on the average effective wind speed sets at Dakhla and Farafra oases. The period from March to May showed the highest resultant drift potential. Controlling sand dune movements is very difficult and more expensive. Keywords Sand dunes · Dakhla Oasis · Dune movement · Sand drift potential · Fryberger model

1 Introduction Sand dune movement towards cultivated lands is a natural cause of desertification that is an important environmental issue in Africa. Soil is one of the most essential resources and the basis of agriculture which is the dominant sector in Africa. It is one of the major sources of income in Africa. The daily lives of, most Africans account for just over 60% of jobs across the continent. Agriculture represents about 25% of the GDP in Africa (World Bank 2015), ranging from 3% in Botswana to 50% A. M. Sharaky (B) Department of Natural Resources, Faculty of High African Studies, Cairo University, 12613, Giza, Egypt © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_7

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in Chad, the Central African Republic, and Sierra Leone (World Bank 2015). The economy of Dakhla Oasis is based on agriculture. The people in the Dakhla Oasis use about 520 springs and ponds. Some of water sources have recently dried out, and others use electric pumps (Sefelnasr 2007). Sand dune encroachment occurs mainly in desert areas with fragile lands, loose sands, limited precipitation, and hot and dry climate. It risks to form nonproductive lands and reduce the ability of cultivated land to produce crops, and livestock. Some cultivated lands decreased their productivities because of soil degradation and desertification. Soil erosion reduced yield in Africa ranging between 2 and 40%, with an average loss of 8.2% (Eswaran et al. 2001). Most of the lands in Africa are classified as arid lands (Lancaster 1996). Africa includes hyper arid region in the world called the Sahara and the deserts of Kalahari and Namib. The present chapter studies the sand dune movement in the Dakhla Oasis in the Western Desert as a case study for the African drylands. Dakhla Oasis is located in the middle of the Western Desert (see Fig. 1). Many researchers studied sand movement. Their researches led to develop mathematical equations for calculations of the sand

Fig. 1 Locations of Dakhla and Farafra Oases (Source Landsat image, https://visibleearth.nasa. gov/images/71790/the-nile-egypt)

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drift rate (Beadnell 1910; Bagnold 1941; Mitwally 1953; Fryberger 1979; Bubenzer et al. 2020). The geology and water resources were discussed in relation to human activities (Bagnall and Tallet 2019). Assessment of water quality and its suitability for various crops were investigated (Fadl and Abuzaid 2017). Some information derived from space-based images have provided good understanding of climate systems and processes in dry regions in Egypt (El Kenawy et al. 2019). Soil morphological and physico-chemical properties as well as soil classification were carried out in west Mawhub area, Dakhla Oasis in order to establish guide parameters for land utilization types on a basis of sustainable agriculture (El-Sayed et al. 2016). They are considered salt-affected soils. The topography and geology of the New Valley in general and the Dakhla Oasis, in particular, have been studied by several authors (Hermina et al. 1961; Said 1962; Ashri 1973; Mansour 1973; Ezzat 1976; Embabi 1979; Hermina 1990; Sharaky 1990; Brookes 1993; Wycisk 1993; Hereher 2010, 2014, 2018; Ghadiry et al. 2012; Hereher and Ismael 2015; Ismael 2015; Hamdan et al. 2016). Ashri (1973) measured the movement of 92 crescentic sand dunes in Kharga Oasis, using two sets of aerial photographs (1944 and 1961), and estimated the rate of dune movement to be about 12 m per year. Embabi (1981) also measured the rate of sand dune movement in Kharga and Dakhla Oases in 1979, using two groups of topographic maps (1:25,000) of 1930 and 1961 f. He reported the average rate of sand dune movement between 5.5 and 9 m per year for Dakhla and Kharga Oases (Embabi 1979). Embabi (1981) measured the dune movement in the field for a year, and estimated the sand dune movement to be between 20.8 and 100 m per year. Sharaky (1990) calculated the annual rate of sand dune movement using the aerial photographs of 1961 (scale 1:50,000) and 1982 (scale 1:60,000). The 82 crescentic and 25 longitudinal dunes were selected to measure the movement of sand dunes located in various dune belts, and representing the different dune forms and sizes. After setting the land marks from some permanent topographic features, the morphology of the crescentic dunes including width and length as well as their distances from the toe of slipface to the nearest suitable land mark were measured using a stereoscopic caliper. It has an accuracy of 0.1 mm, and represents the ground distance of 5 and 6 m for the aerial photographs taken in 1961 and 1982. It was not possible to accurately measure the movement of small dunes between from 3 to 17 m in length from these photographs. Fryberger (1979) estimated the annual sand dune movement using the Fryberger’s model of sand drift potential for Dakhla and Farafra sands located to the north of Dakhla. The Farafra sands are considered the primary source of Dakhla sands. A GIS-based model was developed for measuring sand dune movement using Landsat images (Ghadiry et al. 2012). The rate of sand dune movement ranged between 3 and 9 m per year. Most of the sand dunes showed a rate movement ranging from 0 to 6 m. A small number of sand dunes showed a movement rate ranged from 6 to 9 m.

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2 Sand Dunes in Africa Sand dune sand occupies more than 18% of the drylands in Africa. The major sand dune types in Africa are linear and crescentic with some star dunes.

2.1 Sahara Dunes The Sahara is the largest non-polar desert in the world, with a total size of 9.4 million km2 (Lancaster 1996). The rainfall in the Sahara is very low in the northern and southern fringes, and nearly non-existent over the central and the eastern part. Most of the areas in Sahara have rainfall below 20 mm. The Sahara Desert constitutes more than 86% of the African deserts with high temperature and strong winds. Drifting sands cover about one fifth of the Sahara Desert area (see Fig. 2), forming the world’s most massive sand seas. The sand-transport pathways are influenced by the dominance of the trade-wind circulation, N-S and NE-SW. The rate of sand dune movement is between 5 and 15 m per year dependent on the dune morphology (Beadnell 1910; Sharaky et al. 2002; Embabi 1981; Haynes 1989). The smaller dunes move faster than the larger ones. The major types of dune in the Sahara are linear and crescentic. Star dunes are found only in the dune sand seas in Algeria and Libya (Bread et al. 1979).

Fig. 2 Sand dune distribution in the Sahara Desert

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Fig. 3 Sand dune distribution in the western Kalahari Desert and sand drift potential (Conoco 1987)

2.2 Kalahari Dunes The Kalahari area is located in the great sand-covered plain surface at 800–1,200 m asl, stretching about 932,396 km2 across Botswana, Namibia, and South Africa (Lancaster 1996). Linear sand dunes are the dominant types (see Fig. 3). In the geologic history up to twenty thousand years ago, the Kalahari sand dunes have been stabilized through vegetation. In difference to the Sahara Desert, the Kalahari receives too much rainfall ranging between 25 and 250 mm/yr and causing dune stabilization.

2.3 Namib Sand Dunes The Namib Desert lies along the Atlantic coast. The dune belts of crescentic and linear dunes characterizes the Namib (see Fig. 4), and are the oldest dunes in the world about 30 million years old. The Namib dunes cover more than 32,500 km2 .

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Linear dunes

Crescentic dunes Star dunes Atlantic Ocean

Fig. 4 Spaceborne radar image of the Namib Sand Sea, showing parallel dune zones (54.2 × 82.2 km) (Source Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour1994, NASA https://www.jpl.nasa.gov/spaceimages/details. php?id=PIA01856)

In the Namib Desert, the linear sand dunes in the northern parts of the sand sea have widths of about 600 m. The annual rate of sand dune movement is about 0.1 m/yr Bristow et al. 2007). Star dunes occur in the inland of the Namib Desert It shows an active dune movement, because of the decrease of wind energy from the coast (Bread et al. 1979).

2.4 Topography of Dakhla Oasis Dakhla Oasis is a depression surrounded by a precipitous escarpment running toward WNW direction for 250 km (Said 1962). The floor of the depression slopes gently to the NE. The landscape of Dakhla Depression is classified into (El-Shazly et al. 1976): 1. The northern structural plateau that ranges from 420 m above mean sea level (amsl) at Sikkat Abu Minqar to 600 m amsl (Bagnall and Tallet 2019). The plateau is dominated by calcareous rocks that are underlain by shales and sandstone. The transition from the northern plateau to the depression floor is marked by a steep escarpment dissected by dry drainage lines and promontories.

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2. Central Piedmont plain that represents the low area confined between the floor of the escarpment and the southern structural plain. 3. Southern structural plain that occupies the southern extension of Dakhla depression. It is underlain by the Nubia Sandstone Formation. The surface of this floor rises to more than 200 m. 4. Gabal Edmonstone is an isolated hill detached from the plateau and occurs about 18 km west of Qasr. It has an elevation of about 465 m (amsl) and 300 m above the depression plain (Brookes 1993).

2.5 Geology of Dakhla Oasis The Dakhla Depression dips gently northward. They crop out at the cliff (Ezzat 1976). The geologic rocks of Late Mesozoic-Early Cenozoic rocks which form the primary sedimentary cover, are subdivided into lithostratigraphic units (see Fig. 5). The rocks of geologic formations in the Dakhla depression form five units (El-Shazly et al. 1976; Said 1962): 1. Chalk: The Chalk is snow-white and varies in thickness from 20 to 50 m. It forms the scarp of the northern plateau. 2. Dakhla Shale: The Dakhla shale overlies a hard brown limestone bed, about one meter in thickness, which caps phosphatic beds.

Fig. 5 Geological map of the Dakhla Oasis (Conoco 1944). Lithostratigraphic units (ElKhawaga et al. 2005)

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3. Phosphate beds: The Phosphate beds extend over the whole of the escarpment that bounds the greater Dakhla area from Qasr to Teneida. 4. Variegated Shale: Red clays with some green beds from the base of the depression. They are formally known as Variegated shales and later called Mut Formation by Fay and Degen (1984). 5. Nubian Sandstone: The Nubian Sandstone Formation on the Dakhla depression extending southwards forms a gently rising desert. It is classified into three main members from Landsat-1 satellite images. Dakhla depression was formed by erosion during Oligo-Miocene times (Mansour 1973; Beadnell 1901). Differential weathering in the thick shale section capped by limestone caused successive retreat of the scarp to the north during the Pleistocene.

2.6 Land Use and Land Cover in Dakhla Oasis The cultivated lands in Dakhla Oasis was doubled to about 210 km2 (52,000 Fadden) in 2011 from 110 km2 in 1984 (Kato et al. 2014). A slight increase in the cultivated lands was recorded from the Landsat 8 OLI/TIRS C1 Level-1 images between 2014 and 2019 (see Fig. 6). A false color composites image was produced from three bands 2, 3 and 4 of SPOT4 satellite images of 1971 and 2011 (Kato et al. 2014). The visual interpretation helped to give a general idea about land cover changes with time. A noticeable change was recorded in areas of new land reclamation in the Dakhla Oasis where some of the deserts were changed to productive lands.

2.7 Types of Sand Dunes in Dakhla Oasis The sand dunes in Dakhla Oasis cover a surface area of about 600 km2 . They are concentrated in the western part of the oasis, west of the longitude 29° E. The sand dunes form five parallel dune belts running southwards. They are perpendicular to the longitudinal axis of the depression (see Fig. 7). In different to northeast African dunes, the sand dune belts in Dakhla move counterclockwise around a center close to Gabal Abu Tartur (29° 43’ E and 25° 33’ N). There are two main types of sand dunes in the Dakhla Depression. They are crescentic and linear dunes (see Fig. 8). Crescentic dunes are commonly referred to as barchan dunes. The slope of slip faces of crescentic dunes varies between 31 and 34°. The inclination of the windward slope is more gentle and variable depending on the dune size. It ranges from 3 to 10° (gentle to moderate slope). Crescentic dunes form ridges, commonly known either barchanoid or transverse ridges showing a single slip face on each arc.

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Feb. 16, 2019

N

10 km Feb. 18, 2014 Fig. 6 Cultivated lands (green) in Dakhla Depression from Landsat 8 OLI/TIRS C1 Level-1 (Source The Operational Land Imager [OLI] and Thermal Infrared Sensor [TIRS])

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Fig. 7 Distribution of sand dune belts in the Dakhla Depression (Source Uncontrolled mosaic of 1961-aerial photographs)

Complex crescentic dunes in Dakhla Depression include mounds or ridges on which subsidiary dunes of different types. They are the most prevailing sand dune types in the Dakhla Depression. The sand dunes consist of parallel rows of crescents that have joined to form sand ridges with a very steep slip faces oriented normal to the

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wind direction wind direction

windward face slip face

horn

Crescentic

Barchanoid

wind direction

Linear dune

100 m

Linear Fig. 8 Types of sand dunes in Dakhla Oasis, Egypt (Source from Google Earth map acquired February 2019)

prevailing wind direction. The linear dunes are commonly referred to as longitudinal or seif dunes (McKee 1979). They take place in the southern segment of the eastern dune belt in Dakhla Depression. The linear dunes have an average width of 30 m and length up to 1,000 m. The sand dunes types and their distribution in the Dakhla Depression vary by wind regime and speed, distance from the escarpment of the northern plateau, space between dunes and local landforms.

2.8 Grain Size of Sand Dunes of Dakhla Oasis Mechanical analysis of 126 dune sand samples showed that the average of the grain size ranges from 0.13 to 0.34 mm with an average of 0.22 mm (Sharaky 1990). The grain size of the linear dunes is slightly finer than that of the crescentic dunes. The dune sands are represented by a unimodal distribution denoting a source of one population. The dune sands range in sorting from well to moderately sorted. The slip faces referred to as lee-slopes are better sorted. The Dakhla dune sands

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are classified as fine sands, well to moderately sorted, fine skewed, and mesokurtic. Microenvironments of the dunes show much overlap in properties of the grain size and small fairly consistent differences. The barchan crests and the eastern flanks of the linear dunes are the coarsest, less sorted, more positive-skewed, and more leptokurtic.

2.9 Sand Grain Morphology in Dakhla Oasis The Dakhla dune sand grains are generally sub-rounded with an average roundness of 3.3ρ. The microenvironments of the crescentic dunes show a slight variation in the roundness of their quartz grains. The coarse grains are more rounded and spherical than the fine grains. The sand grains did not show any regular change in roundness with distance indicating that the sands are transported for a long distance. Quartz grains forming linear dunes are slightly more rounded and spherical than those of the crescentic dunes. The reason could be related to the greater surface area subjected wind energy in linear dunes. The examination of quartz grain surface using a scanning electron microscope showed that the grains are mainly affected by mechanical features and less chemical features. The mechanical features are represented by dish-shaped concavities, elongated depressions, upturned plates, parallel ridges, arcuate, circular, polygonal and star features. The examined chemical features include solution etching pits, fracture fillings, and silica precipitation to give the form of turtle-skin (Philip et al. 1992).

2.10 Mineral Composition of Dune Sands of Dakhla Oasis Dakhla dune sands are generally uniform in mineral composition. They have mainly composed quartz with a minor amount of carbonate grains (calcite and dolomite). A minor amount of foraminifera, rock fragments of shale and phosphates are recorded with quartz (Sharaky 1990). The carbonate content averages 5.8%, being slightly higher in crescentic than in linear dunes. The source of carbonates is most probably the Lower Eocene limestone capping the northern plateau. Quartz is the most abundant light mineral in the mixture of fine to very fine sand fractions, while feldspars are relatively rare. The quartz grains show frosting due to pitted surfaces with grooves and cracks that filled by iron oxides. The Dakhla dune sands varies in color from very pale brown (10 YR 7/4 in Munsell Color Chart) to light yellowish brown (10 YR 6/4) in the dry state. The color of wet sands is intense brown (7.5 YR 5/6). The reddening of sand grains in the Dakhla depression slightly increases eastwards from the western belt and in the direction of transportation southwards. Heavy minerals of fine and very fine sand grains are mostly concentrated in the outer belts, and locally on the crests of sand dunes. They average 0.9 and 0.7% in

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the linear and crescentic dune sands, respectively. Opaque minerals are the heaviest mineral group recorded in the dune sands. They represent 80% of the heavy fraction. The opaque minerals are goethite, hematite, magnetite, and limonite. The non-opaque minerals are represented by a suite of minerals enriched in ultra-stable zircon and tourmaline, and meta-stable minerals such as epidote, garnet, and staruolite. The ultra-stable minerals are concentrated on the dune crests and the eastern flanks of crescentic and linear dunes. Zircon is the most abundant non-opaque mineral in the crescentic dune sands, averaging 35.5%, but it is next to epidote in the linear dune sands (Sharaky 1990). The abundance of zircon indicates that these minerals are being reworked from older sediments, most probably the Nubian sandstones.

3 Movement of Sand Dunes in Dakhla Oasis The sand dunes in Dakhla Depression are in continuous movement southwards. The sand dune encroachment threatens roads, houses, water wells, and cultivated lands. Two groups of aerial photographs for the western area of Dakhla Depression (21 years apart) were used to determine the rate of sand dune movement. The first group is a set of 82 crescentic dunes, and the second set includes 25 linear dunes. They were chosen to measure the sand dune movement of different dune belts, types, forms, and sizes. The dimensions of the crescentic dunes including width and length, distance from the toe of slipface to a distinct land mark were measured. The Dakhla crescentic sand dunes range in movement between 0.5 and 14 per year, in average 5.8 m per year. The dune movement differ from one place to another based on local conditions. The most important factors of dune movements are dune size and local wind velocity. In general, small crescentic dunes move faster than the larger ones. The sand dunes in the northern part are smaller in size and move faster than the massive southern sand dunes. The crescentic sand dune grow in width and length in average 25 and 37 cm per year, respectively.

4 Sand Drift Potential (SDP) in Dakhla Oasis The prevailing wind in Dakhla Depression is NNW (see Fig. 9). Winds of gale force and above are rare in the depression. The annual average surface wind speed more than 5.14 m/s is about 13% (Sharaky 1990). The Fryberger formula of sand drift potential was applied to the average effective wind speed calculated from the wind data of Dakhla and Farafra meteorological stations (1970–1980) (Fryberger 1979). The wind values representing the relative rates at which winds of different average velocities can move sands are called weighting factors (Fryberger 1979). They are derived by substituting values of wind velocities (average wind speed of a velocity category) for the weighting formula of Lettau (McKee 1979) as follows:

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Annual

Ranges of speed (knots)

0 5 10 15

%

Scale of direction

%

Fig. 9 Wind roses of Dakhla Oasis, 1971–1980

q = V2 (V − Vt ),

(1)

where q = rate of sand drift potential, V = wind velocity at 10 m height and Vt = impact threshold velocity. The energy of surface winds was classified in the desert regions, depending on the average annual drift potential, into the following groups (Fryberger 1979): (1) lowenergy environment, with the drift potential (DP) less than 200 vector units (VU); (2) intermediate-energy wind environment with DP ranging between 200 and 399 VU; and (3) high-energy wind environment in which DP is greater than 400 VU. The threshold velocity of 0.2 to 0.3 mm quartz sand grains was estimated as 5.97 m/s for many desert dune sands (Fryberger 1979). This value was rounded to 6.17 m/s and applied in this study. The average value of the annual drift potential at Farafra Depression (1882 VU) is much higher than that at Dakhla Oasis (787 VU). Dakhla

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and Farafra Depressions belong to the group of high energy wind environments according to the energy classification of surface winds in the arid regions (Fryberger 1979). Figure 10 plots monthly and annually sand roses for the 12 directions in Dakhla and Farafra Oases. The arms of the sand rose are proportional in length to the sand drift potential values. The sand rose diagrams show that the DF differs significantly by direction. They also change monthly according to the wind velocity. In general, the annual sand rose of the Dakhla Oasis is wide-unimodal; more than 90% of the DP belong to four adjacent directioca1 categories from 285°-314° to 15°-44°. Farafra Oasis is obtuse bimodal; two mode directions form 44% of DF in the directions 255°-284° and 15°-44°. The net sand transport potential was calculated from each sand rose diagram using the Pythagorean theorem, which is referred to as the resultant drift potential (RDP) and expressed as vector units (Fryberger 1979). As shown in Fig. 10, April has the highest RDP of 91 and 298 VU at Dakhla and Farafra Oases, respectively.

Dakhla

Fig. 10 Sand roses of Dakhla and Farafra oases

Farafra

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Fig. 11 Monthly variations of resultant drift potential (RDP) at Dakhla and Farafra OPases

The resultant drift potential at Dakhla oasis moves to different direction from SE in January to April to SSE in May. Then, it changes from SSE in June to the south in Ju1y–November. The resultant drift potential directs again toward SE in December. Comparing the annual RDP at Farafra and Dakhla depressions, it is relatively higher at Farafra than at Dakhla (see Fig. 11). The annual RDP moves toward SE (131°) with the main direction of the Great Sand Sea in the Western Desert. Thus the main source of Farafra dune sands is most probably the Great Sand Sea located at about 50 km west of the Farafra Oasis. Wind variability is classified as low if the value is less than 0.3, intermediate if 0.3 to less than 0.8, and high if 0.8 or greater. The results showed that wind variability at Farafra is intermediate (0.5), and at Dakhla high (0.8).

5 Dune Movement Threat in Dakhla Oasis The villages in Dakhla Oasis such as Gadida, Qalamun, Mushiya, and Ezab al-Qasr suffer from the migration of sand dunes (see Fig. 7). The dunes attack cultivated lands (see Fig. 12A, B and C), water wells and irrigating canals (see Fig. 12C and D), roads (see Fig. 12E) and houses (see Fig. 12F). The northern ends of Dakhla dune belts usually move to threaten the Dakhla-Farafra road after such wind storm. Some telephone poles have been leng-thened several times. Moving dunes attack several roads in the Western Desert of Egypt as well as in Dakhla. The sand dune encroachments usually threaten highways such as Kharga-Assiut, Kharga-Dakhla, and Bahareya-Giza.

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a

b

c

d

e

f

Fig. 12 Sand dune movement threatening in Dakhla Oasis (a) Cultivated land at Gadida (b) Cultivated land at Mut. (c) Former cultivated land at Ezab El-Qasr. (d) Sand-buried irrigated channel at Ezab El-Qasr. (e) Dakhla-Farafra highway at Mawhub. (f) Sand-buried houses at Mushiya

It is difficult and expensive to controlling of sand dune movement in Dakhla Oasis. Some attempts were done to stabilize dune in the Dakhla Depression. Fixation using plants or trees can protect cultivated lands and houses. However, it can be possible only in the places where freshwater is available. Sand fences are often built in Dakhla Oasis. These use two horizontal reeds fixed 50 cm apart, and are tied with vertical palm leaves by ropes. A primitive type of fence are one meter high and can be used as a temporary method. In general, the protection against sand dune movements in Dakhla Oasis, as in many desert regions, is very difficult and expensive. The most economic way of

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treating the migrating dune belts is to avoid their directions. As to the main roads between cities that are subject to sand encroachment, the sands are removed mechanically throughout the year. The easiest way, on the other hand, of reclaiming new areas is to get out of the way of migrating dune belts.

6 Conclusions The surface of African continent includes a gigantic plateau with shallow depressions. More than one-third of the world’s arid lands is in Africa, namely Sahara, Kalahari, and Namib deserts. Sand dunes which is Africa’s most distinctive aeolian feature cover one-fifth of the African deserts. Among the major dune types in Africa that are longitudinal and crescentic dunes, the longitudinal ones are the most common. In Egypt, more than 17% of the land surface is covered by sand dunes. The Great Sand Sea in the Western Desert constitutes about 80% of the Egyptian dunes. As to Dakhla Oasis, the two main types of sand dunes are crescentic and longitudinal or linear dunes. The compound crescentic dunes called barchanoid ridges are the most common type. The linear dunes are common in the southern part of the eastern dune belt. Dakhla sand dunes continues to move from north to south. They threaten highways, houses, cultivated lands, irrigated channels, and water wells. The Dakhla dune movements follow the directional variability of the wind regime and speed, distance from the northern plat-eau. The rate of Dakhla crescentic dune movement ranges between 0.5 and 14 m per year, and averages 5.8 m per year. The southern extremity of linear dunes southwest of Mut ranges between few meters and 15 m/yr with an average of 7.5 m/yr. The average rate of crescentic dune growth is 25 cm/yr for width and 37 cm/yr for length. The drift potential (DP) varies significantly from one direction to another according to the effective wind velocity. The average annual DP at Dakhla is 787 VU, while it is 1882 VU at Farafra. Spring months showed the highest RDP.

7 Recommendations Controlling of dune movement in Dakhla Depression is very difficult and expensive. Therefore, it is better to overcome threatening dunes by avoiding their way, and the new reclamation land should be in between the dune belts. Laser stations are required to monitor the movement of sand dunes in Dakhla Depression.

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Bagnold RA (1941) The physics of blown sand and desert dunes. Chapman and Hall, London, 265 p Beadnell HJL (1901) Dakhla oasis; its topography and geology, Geol Surv Dept, Cairo, 107 p Beadnell HJL (1910) Sand dunes of the Libyan desert. Geol J 35:359–395 Bread CS, Fryberger SG, Andrews S, McCauley C, Lennartz F, Gebel D, Horstman K (1979) Regional studies of sand seas using Landsat (ERTS) imagery. In McKee ED (ed) A study of global sand seas: U.S.G.S. Prof. Paper 1052:305–397 Bristow CS, Duller GAT, Lancaster N (2007) Age and dynamics of linear dunes in the Namib Desert. Geology 35:555–558 Brookes IA (1993) Geomorphology and quaternary geology of the Dakhla Oasis region, Egypt. Quat Sci Rev 12:529–552 Bubenzer O, Embabi NS, Ashour MM (2020) Sand Seas and Dune Fields of Egypt, Geosci 10:101 https://www.mdpi.com/2076-3263/10/3/101 Conoco (1987) Geologic map of Egypt. Egyptian General Authority for Petroleum (UNESCO joint map project), 20 sheets, scale 1:500,000, Cairo, Egypt El Kenawy AM, Hereher ME, Robaa SM (2019) An assessment of the accuracy of MODIS land surface temperature over Egypt using ground-based measurements. Remote Sens 11(20):2369. https://doi.org/10.3390/rs11202369 ElKhawaga ML, Philobbos ER, Riad S (2005) Stratigraphiclexicon and explanatory notes on the geological map of the South Western Desert, Egypt, 81 sheets, scale 1:250,000. UNESCO, Cairo El-Sayed MA, Abd El-Aziz SH, El-Desoky AI, Selmy SAH (2016) Pedomorphic features and soil classification of Gharb El-Mawhob area, El-Dakhla Oasis, Western Desert. Egypt Middle East J Agric Res 5(2):247–257 El-Shazly EM, Abdel Hady MA, El-Kassas IA, Salman AB, El-Amin H, El-Shazly MM (1976) Geology of Kharga-Dakhla oases area, Western Desert, Egypt from Landsat1 Satellite Images, Remote Sensing Center, Cairo, Egypt Embabi NS (1979) Barchan dune movement and its effect on economic development of the Kharga Oasis depression (in Arabic). J Middle East The Middle East Research Center, Ain Shams University 6:51–84 Embabi NS (1981) Barchans of the Kharga depression. Ann Geol Surv Egypt 11:141–155 Eswaran H, Lal R, Reich PF (2001) Land degradation: an overview. In: Bridges EM, Hannam ID, Oldeman LR, Pening de Vries FWT, Scherr SJ, Sompatpanit S (eds) Responses to land degradation: Proc. 2nd. International conference on land degradation and desertification, Khon Kaen, Thailand. Oxford Press, New Delhi, India Ezzat MA (1976) Exploration of groundwater, Kharga Oasis. Desert irrigation, Ministry of Irrigation, Cairo, Egypt, 203 p Fadl ME, Abuzaid AS (2017) Assessment of land suitability and water requirements for different crops in Dakhla Oasis, Western Desert, Egypt. Int J Plant Soil Sci 16(6):1–16 Fay M, Degen H (1984) Mineralogy of Campanian/Maastrichtian sand deposits and a model of basin development for the Nubian group of the Dakhla basin (Southwest Egypt). Berliner Geowiss Abh A50:99–117 Fryberger SG (1979) Dune forms and wind regime. In: McKee ED (ed) A study of global sand seas: U.S.G.S. Prof. Paper 1052: 137–170 Ghadiry M, Shalaby A, Koch B (2012) A new GIS-based model for automated extraction of sand dune encroachment case study: Dakhla Oases, Western Desert of Egypt, The Egypt J Remote Sens Space Sci 15:53–65 Hamdan MA, Abdel Refaat AA, Wahed M (2016) Morphologic characteristics and migration rate assessment of barchan dunes in the southeastern Western Desert of Egypt. Geomorphol 257:57–74 Haynes CV (1989) Bagnold’s Barchan: A 57-Yr record of dune movement in the eastern Sahara and implications for dune origin and paleoclimate since Neolithic times. Quat Res 32:153–167 Hereher ME (2010) Sand movement patterns in the Western Desert of Egypt: an environmental concern. Environ Earth Sci 59:1119–1127

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Hereher ME (2014) Assessment of sand drift potential along the Nile Valley and Delta using climatic and satellite data. Appl Geogr 55:39–47 Hereher ME (2018) Geomorphology and drift potential of major aeolian sand deposits in Egypt. Geomorphol 304:113–120 Hereher ME, Ismael H (2015) The application of remote sensing data to diagnose soil degradation in the Dakhla depression, Geocarto International, Taylor & Francis, pp 527–543. https://doi.org/ 10.1080/10106049.2015.1059901 Hermina M (1990) The surroundings of Kharga, Dakhla and Farafra oases. In: Said R (ed) The geology of Egypt. Balkema, Rotterdam, pp 259–292 Hermina MH, Ghobrial MG, Issawi B (1961) The geology of the Dakhla area. Geol Surv Min Res Dept Cairo, 33 p Ismael H (2015) Evaluation of present-day climate-induced desertification in El-Dakhla Oasis, Western Desert of Egypt, based on integration of medalus method, GIS and RS techniques. PESD 9(2):47–72 Kato H, Elbeih S, Iwasaki E, Sefelnasr A, Shalaby A, Zaghloul E (2014) The relationship between groundwater, landuse, and demography in Dakhla Oasis, Egypt, J Asian Netw GIS-based Histl Stud 2:3–10 Lancaster N (1996) Desert environment. In: Adams WM, Goudie AS, Orme AR (eds) The physical geography of Africa. Oxford University Press, New York, 429 p Mansour HH (1973) Geological and sedimentological studies on the Dakhla Oasis area, Western Desert, Egypt. Ph.D. thesis, Assiut University, Egypt McKee ED (ed) (1979) A study of global sand seas: U.S.G.S. Prof. paper 1052, 421 p Mitwally M (1953) Physiographic features of the oases of the Libyan Desert. Bull Desert Inst Cairo 2:32–48 Philip G, Labib TM, Sharaky AM (1992) Sand dunes of the Dakhla depression, Western Desert, Egypt: geology of the Arab world, University of Cairo, pp 273–282 Said R (1962) The geology of Egypt. Elsevier Pub. Co., Amsterdam, 377 p Sefelnasr A (2007) Development of groundwater flow model for water resources management in the development areas of the Western Desert, Egypt, Ph.D. thesis, Martin Luther University Sharaky AM (1990) Geomorphological studies on sand dunes and ridges in some African deserts. M.S. thesis, Cairo University, 175 p Sharaky AM, Labib TM, Philip G (2002) Sand dune movement and its effect on cultivated lands in Africa: case study: Dakhla Oasis, Western Desert, Egypt. Land degradation in Egypt and Africa (23–24 March 2002), Cairo University, pp 1–15 Word Bank (2015) Agriculture and rural development. http://www1.worldbank.org/publicsector/ pe/pfma07/ARDBrief.pdf Wycisk P (1993) Outline of the geology and mineral resources of the southern Dakhla Basin, southwest Egypt. In: Meissner B, Wycisk P (eds) Geopotential and ecology: analysis of a desert region, Catena supplement 26:67–89

Soil Conditions of Dakhla Oasis, Western Desert, Egypt Abdelaziz B. A. Belal, El-Sayed S. Mohamed, Mostafa A. Abdellatif, and Mohamed A. E. AbdelRahman

Abstract The New Valley Governorate in Egypt is one of the most encouraging territories for agriculture expansion. Therefore, it was necessary to study the land resources in those new areas and understand the spatial nature to determine development priorities. The New Valley governorate holds a zone of around 376.505 km2 . Dakhla Oasis is one of the high need areas for future improvement in Egypt. Also it is considered to be one of the potential priority areas for agricultural development and one of the largest depressions in the Western Desert of Egypt. The evaluation of the land characteristics and its response to the agricultural service operations are very important to agriculture production, planners, land users, feasibility studies, design for land development projects and various engineering works. Furthermore, understanding the most accurate use of soil for specific purposes is necessary to take advantage of all available land resources. This chapter illustrates soil classification, maps, assessing their productivity and suitability for specific crops using remote sensing and GIS techniques in Dakhla Oasis. The dominant soil classification in Dakhla Oasis is the following; Typic Haplargids, Typic Torriorthents, Typic Torripasamments, Typic Haplotorrerts and Vertic Torriorthents, Typic Natrargids, Salic Natrargids, Sodic Haplosalids and Sodic Haplocalcids. The studies showed that most Dakhla Oasis soils are high, moderate and marginal for wheat, sugar, cotton, sunflower, beet, soya bean, maize, watermelon, potato, alfalfa, peach, olive, and citrus. However, Dakhla Oasis soils have some limiting factors for agricultural production such as high soil salinity, sodium saturation, high content of lime, and soil depth. Finally, joining between remote and GIS is a useful asset for sustainable agricultural development. Different soil maps can give an overview for decision-makers and those interested in developing agricultural development in Dakhla Oasis.

A. B. A. Belal (B) · E.-S. S. Mohamed · M. A. Abdellatif · M. A. E. AbdelRahman National Authority for Remote Sensing and Space Sciences (NARSS), Alf-Maskan 23, Joseph Brows Tito St. El Nozha El Gedida, P.O. Box 1564, Cairo, Egypt © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_8

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1 Introduction New Valley Governorate occupies a huge area of the southwestern desert representing 43.6% of the absolute region of Egypt underlie by high groundwater potentiality; accordingly it is included in the agricultural expansion for Egypt (Mohamed et al. 2018b; Allam et al. 2002). The Governorate’s name refers to the declaration of the late Egyptian President Gamal Abdel Nasser in 1958 about the establishment of a valley parallel to the Nile Valley penetrating the Western Sahara for reconstruction and cultivation on the waters of the eyes and wells in order to alleviate overcrowding in the Nile Valley, previously called the southern province (CAPMAS 2017). On October 3, 1959, the first convoy for the reconstruction and rehabilitation of the New Valley arrived and was considered a national holiday celebrated by the province every year. In 1961, the New Valley Governorate was established within the administrative division of the governorates of the Arab Republic of Egypt. It was composed of two administrative districts (markaz): Kharga District and Dakhla District. The oases of Egypt have been known since ancient times. The oasis of Kharga was called the “The Great Oasis” where it occupied a great depression in the desert and its capital is Hybes, which derives its name from the word Habbat, meaning the plow. The Dakhla oasis was called Kantum and its capital (Dess-Dess) meaning (cut off-cut) in terms of the plots of land and cut them for cultivation and Al-Farafra was known as Ta-eh, the land of the cow. New Valley Governorate is situated in the southwest of Egypt in the western desert. It is bordered to the east by the governorates of Minya, Asyut, Sohag, Qena and Aswan, and on the west are the borders of Egypt with Libya and to the north are the governorates of Matrouh, the Bahareya oasis of Giza governorate and from the southern borders Egypt with Sudan. The area of the province is 440098 km2 , identical to 44% of the complete region of the Arab Republic of Egypt and about 66% of the area of Western Sahara. This area includes three oases. They are Kharga, Dakhla and Farafra. Five administrative districts in the province (Kharga-Dakhla-Farafra-Baris-Balat) and the capital is Kharga (Population Clock 2013; Sub-National HDI 2013). New Valley is characterized by a dry climate in the summer warm winter and rare rain, and the Dakhla Oasis described by the most elevated brilliance of the sun on the planet consistently (Retrieved from Climate-Data.org 2013), which can be used as a wellspring of sustainable power source of renewable energy. Also it is characterized by the existence of vast land areas that can be exploited in the establishment of various projects in all fields of industrial, service, agricultural and tourism. The natural factors and geographical conditions of oases assume a significant job in forming the lives of individuals and influencing their ideas and beliefs as well as their economic and social activities. The geological environment is one of the natural factors that Presumably plays a great role in the distribution of the population and shaping the lives of people and society (Retrieved from New Valley Governorate Subdivisions 2018).

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The region has 3.7 million feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) suitable for agriculture and relies on the exploitation of the provision of irrigation water through the drilling of underground wells and also through Sheikh Zayed Canal, which derives its water resources from Lake Nasser. The spread of urbanization and its persistence in a desert area requires an agricultural environment based on available land and water. The New Valley Governorate relies entirely on groundwater for agriculture, drinking, industry and all purposes (till the completion of drilling and operation of Sheikh Zayed Canal). The agricultural and industrial development rates have been dependent on the efforts of the state only in drilling wells, especially in the areas of East Awainat, in Farafra and some areas of Dakhla. The oasis is exposed to many natural hazards spread in the Nile Delta that decease soil quality and agricultural production such as soil salinity and land degradation and prevent the achievement of sustainable agricultural development (Abu-hashim et al. 2016; Mohamed 2013; Mohamed et al. 2013a, b, 2014, 2019a, b, c; AbdelRahman et al. 2019a; Hammam and Mohamed 2018; Hassan et al. 2019). Water is available along the length of the province sand rocks formed in ancient times, known as the Nubian era and extends the rocks of this era to the north of Sudan, and the thickness of the layer of sandstone Nubian between 400 m near the borders of Sudan and 800 m in Kharga and 1200 m in Dakhla and 2000 m in Farafra. The estimated annual flow rate of this groundwater is about 30 m per year, and the annual recharge of Western Sahara is estimated at about 240 million m3 annually. The amount of water that can be exploited from 150 m of Nubian sandstone is estimated at 2340 billion m3 , For 780 years (Abdel-Shafy and Kamel 2016). The low areas of the oasis are similar in their characteristics to the soils of the Nile Delta, where have high content of clay is in the lower fair and also the high soil moisture (Mohamed et al. 2019a; AbdelRahman et al. 2019b) The governorate boasts many mineral resources, the most important of which are the phosphate ore at Abu Tartour plateau, as well as raw materials; zinc, lead, iron, marble, limestone, sand, asphalt, sandstone and sand (Hamimi et al. 2020). The number of wells allocated to drinking water is 104 wells with the daily operation of 107234 m3 /day. There are 50 purification plants distributed in the towns and villages of the governorate. There are 130 water reservoirs in the governorate. Clean drinking water covers all cities and villages in the governorate and the average per capita drinking water is 592 lit/day. Because of populace increment in Egypt and the urgent need for food, it is necessary to maximize the utilization of natural resources for agriculture production, conduct a land evaluation, and study its suitability for crop cultivation. It is the first step to utilize land resources (Mohamed et al. 2014; AbdelRahman et al. 2016). One of the important zones for agricultural expansion is the New Valley governorate. The New Valley is the largest governorate in Egypt; it occupies the southern half of the western desert of Egypt, covering an area of 458,000 km2 , or about 48% of the total surface area of Egypt. Advanced technologies such as remote sensing and geographic information systems (GIS) facilitated the study and evaluation of lands,

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Fig. 1 Location of Dakhla Oasis. Produced by authors

where advanced data for satellite imagery can be used to monitor the different characteristics of soil properties (Mohamed et al. 2018a, 2019b; AbdelRahman et al. 2018)

2 Location of Dakhla Oasis Dakhla Oasis lies in the middle of the Western Desert of Egypt. Its capital is Mut, and is considered as the second capital of the New Valley Governorate. It is about 120 km west of Kharga Oasis, about 300 km west of the Nile Valley and extends around 300 km southeast of Farafra Oasis. It is bounded by the Eocene limestone plateau from the east to the north (El-Sankary 2002), and extends between longitudes 28°14’–29° 45’ E and latitudes 25° 10’–26° 05’ N (Fig. 1).

3 Geomorphology of Dakhla Oasis The area of Dakhla oasis is characterized by various distinct geomorphological features (Shata 1962). It is characterized by a variety of topography where the occupies the low areas down of the plateau. The main topographic units of Dakhla Oasis

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Fig. 2 Geomorphological map of Dakhla Oasis. Produced by authors, 2019

are the depression, sandplain, tableland (flat land), sand sheet, sand dune, inselbergs, pavement plain, playa, river terraces and steep escarpment as shown in Fig. 2 and Table 1. Plateau is a part of a great Tertiary plateau mainly of Eocene age. The Quaternary sediments are represented by the significant Aeolian accumulations that occur in the depression (Hermina et al. 1961). Plateau, broad territory of level upland normally limited by a ledge (i.e., steep slant) on all sides however sometimes and then encased by mountains. The fundamental measures for levels are low relative alleviation and some height.

3.1 Escarpment The escarpment is surrounded the eastern and northern part of Dakhla Oasis, which separates the plateau extended from the depression, where the height of the plateau changes suddenly. escarpment reflects the geological ages in the area and indicates

128 Table 1 Area of the geomorphological units in Dakhla Oasis

A. B. A. Belal et al. Units

Area-km2

Area/Acre

Area/%

Depression

2362.827391

562578

14.4

Escarpment

617.646713

147059

3.8

Footslope

91.189977

21712

0.6

Gravely plains

974.150481

231941

5.9

High terraces

958.325464

228173

5.8

Hill

71.846394

17106

0.4

Inselbergs

47.276586

11256

0.3

Low terraces

1520.958806

362133

9.3

Moderate terraces

1439.302811

342691

8.8

415.871735

99017

2.5

2046.184435

487187

12.5

Pavements plain Plateau Playa

348.418603

82957

2.1

Sand dunes

520.105831

123835

3.2

Sand sheet

544.408432

129621

3.3

Sandy Plain

3810.720288

907314

23.2

640.014665

152384

Table land Total

16409.24861

3906964

3.9 100

the origin of the Dakhla Oasis and erosion factors in addition erosion and faulting was the main factors of escarpment formation. Depression of Dakhla oasis is considered one of the largest depression in Western Desert of Egypt, and is bordered in the north, by a Paleocene plateau which is commencing with an escarpment. Agricultural activities in Dakhla have been concentrated since ancient times in the depression as shown in Figs. 3, 4, and 5. Therefore, it is characterized by biodiversity, and their highly fertile soils have high fertile represent about 14.4% of the total area.

3.2 Sandy Plain The unit of sand plain is covered mainly by sand, which may have originated by action of sand dunes„ wind and water erosion. In addition sandplain may formed by sand deposited by water action during floods (Schoeneberger and Wysocki 2017). The sandy plain is occupied by Cretaceous rocks shaped of what is known as the Nubian formation, which is basically sandstone. This plain is gradually slopes northward to a series of depressions known as oases. The soil depth of sand plain is deep as shown in Fig. 6. It represented approximately 23.2% of the area.

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Fig. 3 Field crops in Dakhla Oasis. Photo taken by authors, 2017

3.3 River Terraces River terraces are formed as a result of sediment deposition on floodplains or adjacent to channels by overbank sedimentation during flood events. Fluvial incision into these unconsolidated sediments, which can be driven by changes in base level or high river discharge, causes the development of a steep scarp face that delimits the proximal edge of the flat terrace surface (Westaway et al. 2008). There can be various such terraces at various statures showing previous river bed levels. The river terraces may happen at a similar height on either side of the streams wherein case they are called paired terraces. The soil depth river terraces is shallow as shown in Fig. 7.

3.4 Sand Dune The process of formation of sand dunes takes a long time, where the sand dune carried by wind for a distance depends the topography and wind speed and also obstacles present in the region. The sand dunes take many forms according to the direction of the wind and the existing obstacles, whether trees or weeds and others. Anyhow the dominant sand dune in Dakhla Oasis are Crescent, star, linear, transverse and

130

Fig. 4 Horticultural crops in Dakhla Oasis. Photo taken by authors, 2017 Fig. 5 Soil profile of the cultivated land in depression. Photo taken by authors, 2017

A. B. A. Belal et al.

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Fig. 6 Deep soil profile of sand plain. Photo taken by authors, 2017

Fig. 7 Shallow soil profile. Photo taken by Authors, 2017

barchans dunes (McKee 1979). Sand dunes are considered to be one of the obstacles to the development of agriculture in the Dakhla Oasis as shown in Fig. 8.

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Fig. 8 Sand dune in Dakhla Oasis. Photo taken by Authors, 2017

3.5 Sand Sheet Sand sheet unit cover a wide area in Dakhla Oasis, this area is flat to almost flat and characterised by low vegetation cover as the precipitation rate is low. sand set is cover by sand dune (Breed et al. 1987), the thickness layer of sand sheet is less than 20 m of Eolian sand sheet sedimentary successions (Mountney 2006), due to these sedimentation conditions are transitional to dune fields or because geographic position difficult their accumulation

3.6 Inselbergs Inselberg is one of the landforms resulting from erosional processes. For an inselberg to form, there has to be pronounced variations in the level of weathering of the land surface. These include the buttes, mesas and conical hills. They are well represented where a hard cap rock overlies relatively softer sediments. Inselberg can be a range or hill that stands isolated rising like an island from the flat plains. Although they vary in names as they vary in forms, they are all bald domically shaped and steep sided (Twidale 1962).

Soil Conditions of Dakhla Oasis, Western Desert, Egypt

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3.7 Pavement Plain Pavement plain almost characterized by mixed surface of fragments of gravel, boulders in arid areas and sim arid region in varies geomorphological features and different level of slope and can recognize in desert areas, fans and also find them in river terraces that formed during to the Pleistocene Epoch. Pavement plain in Dakhla Oasis formed by the action of floods, its surface characterized by coarse and medium sediments materials overlying soil surface

3.8 Playa Playa are preeminently receptacles for sediment, and water and their nature is in large measure determined by their old sedimentary and hydrological properties characterized by fine grained clastic and non-clastic sediment (Cook and Warren 1973). Playa unit is found in low-lying areas in Dakhla Oasis, characterized by the high salinity of the surface layers, which form a layer or crusts of soluble salts. The surface is characterized by the high saline water table. The Playa finds in Dakhla Oasis in the middle of the depression, where the fine clay, silt are mix ed with salt layers and form Solid layers after the water evaporates, as it is characterized by the presence of Salt tolerance plants as shown in Fig. 9.

Fig. 9 Playas in Dakhla Oasis. Photo taken by Authors, 2017

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A. B. A. Belal et al.

3.9 Footslope This unit is located at the foot base of the hills, plateau and mountains and is considered a transitional area between the up and low lands (shoulder, back slope). It is also characterized by the presence of weathering sediments from the surrounding heights, and it is characterized by hardban subsurface layers

4 Climate Data of Dakhla Oasis Dakhla Oasis is characterized by an extremely arid belt. As the average annual temperature reaches 23.55 °C, the maximum temperature is 40.3 °C in July meanwhile, the minimum temperature reaches 5.5 °C during January. The average monthly wind speed is 4.50 m/s. The average relative humidity is 34.92%, and the minimum humidity values is 25.33% in May and July and reaches a maximum of 48% in December. The maximum evaporation is observed during the months with hotter and dryer conditions, where it reaches 24.8 mm/day in June. The minimum value (7.7 mm/day) was noticed in the coldest months. i.e. December and January. The soil temperature regime is hyperthermic, and the soil moisture regime is aridic (Hamed and Khalafallah 2017; El-Sayed et al. 2016) (Table 2). Table 2 Meteorological data of Dakhla Oasis Month

Rainfall (mm)

Temperature (°C)

mms

Max

Jan.

0.01

23.90

4.30

Feb

0.20

26.80

Mar

0.10

31.50

Apr

0.10

May Jun

Min

Mean

Evaporation (mm/day)

Relative Humidity %

14.10

8.80

35.40

4.70

15.80

11.40

29.60

8.40

20.00

17.70

22.80

37.00

12.20

24.60

24.40

19.50

0.10

39.00

17.00

28.50

30.40

18.50

0.00

39.90

21.50

30.30

37.20

17.00

Jul

0.00

41.70

21.50

31.60

37.60

17.70

Aug

0.00

41.40

22.00

31.70

36.80

18.90

Sep

0.00

39.60

25.00

32.30

31.40

20.70

Oct

0.00

35.50

16.00

25.60

21.90

25.80

Nov

0.00

29.10

9.90

19.50

14.00

30.70

Dec

0.00

25.30

6.00

15.70

10.00

34.90

Average

0.50

34.20

14.04

24.10

23.50

24.30

Note Data is average of a period from 1980–2010. Source El-Sayed et al. (2016)

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5 Soil Characteristics of Dakhla Oasis Hamed and Khalafallah (2017) studied available nutrients and some soil properties of Qasr Village in Dakhla Oasis. The study stated that the texture class was varied from loamy sand to clay texture. Sand content ranged from 28 to 89 while silt from 4 to 37 and clay from 7 to 47%. The bulk density was ranged from 1.22 to 1.73 g/cm3 with a mean of 1.42 g/cm3 . The saturation percentage was ranged from 16 to 76%, with a mean of 52.10%. It was noted that the area characterized by pH values varied between 7.5 to 8.9, the average value of pH was 7.89 as shown in Fig. 10. The high pH values may be due to the nature of the area that is characterized by calcareous origin material that affects on the fertile status of the soil as well as soil colloids and the degree of solubility of salts and elements such as extractable phosphorus Faragallah (1995) and Brady and Weil (2002) stated that the optimal pH range for plant nutrient availability is in the range of 6.5 to 7.5. CaCO3 content ranged between 2.85 and 26.82%. The high soil salinity and/or even soil texture could be probably the reasons for these high amounts of CaCO3 (Chaney and Slonim 1982). Generally, the depth of percolating rainwater, evaporation rates and the position of the area are main important factors affecting the accumulation of calcium carbonate in the soils (El-Sayed et al. 2016).

Fig. 10 Special distribution of pH values in Dakhla Oasis. Source Modified after Ismael (2015)

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In Upper Egypt CaCO3 content in some soils found to be ranged from 0.15 to 49.00% (Ghoneim et al. 1984). Hamed and Khalafallah (2017) reported that soil organic matter is ranged between 0.1 to 1.5%, where mean value of soil organic matter is approximately 1%. Furthermore the low values of soil organic matter were found in the sandy soil as the agricultural activities is very low. On the other hand the high values were recognized in the cultivated land that charachtrized by fine and medium texture (El-Sayed et al. 2016). The cation exchange capacity (CEC) values were ranging between 10 to 38 cmol (+) kg−1 . This result agrees with those obtained by Reid and Dirou (2004). OM and clay content are considered as a source of nutrients (Maji et al. 2005; Chude et al. 2011) by attracting more cations and provide extra exchange sites to get the cations adsorbed in it. On the other hand, the effect of soil tillage may be led to the low values of CEC which could be attributed to the reduction of soil organic matter (Paz-Gonzalez et al. 2000). SAR values ranged from 0.78 to 5.56, which showing that most of soils have values of less than 8, the non-sodic soils cover about 77% of area soils. The soil depths of Dakhla are varying between shallow to deep as they ranged between 70 to > 150 cm (Hamed and Khalafallah 2017). Hamed and Khalafallah (2017) found that N values were with a mean value of 99.37 mg/kg of total values that ranged from 70.31 to 170.22 mg/kg, while P values were with a mean value of 31.32 mg/kg of total values that ranged from 14.33 to 52.71 mg/kg, and K values were with a mean value of 121.93 mg/kg of toatal values that ranged from 82.36 to 240.04 mg/kg for. The addition of plants residual and organic fertilizers is the main practices in the area could be the reason of founded high level of available N, P, and K as a result of providing a substrate for microbial growth, and subsequent microbial activity (Suge et al. 2011)

6 Soil Classification of Dakhla Oasis The examination of the soils provides the basis for placing them into taxonomic and mapping units. Based on joint complication of the morphological features already presented physical and chemical properties, we could explore the capability of these soil properties to reply the requirements of different diagnostic horizons in order to find the suitable taxonomic position of the different soil mapping units in the study area. Soils belonging to the taxonomic units could be differentiated into orders, suborders, great groups and subgroups (Soil Survey Staff 2014). According to ElSayed et al. (2016) two soil orders are dominated in the Dakhla Oasis, Aridisols and Entisols, Aridisols are found throughout the world in desert environments. Salids, Calcids and argids are the most common suborders belonging to Aridisols present in the studied area. Soils of this order are classified according to morphological, physical and chemical properties to three sub great groups, namely; Typic Natrargids, Salic Natrargids and Sodic Haplosalids. Entisols order: they are characterized by the lacking of diagnostic horizons. Psamments and Orthents are the most common suborders belonging to Entisols present in the studied area. Soils of this order are

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classified to Typic Torri psamments, Typic Torriorthents, Vertic Torriorthents and Sodic Torriorthents.

7 Land Evaluation of Dakhla Oasis 7.1 Land Capability Land capability express of the future potential of soil used within specific management practices. The goal of knowing the soil capability potential is to analyze and examine all relevant data to identify a combination of agricultural measures for the appropriate use and management of land, which ensures the conservation of resources without causing soil degradation. Yousif (2014) have been evaluated soil of Dakhla Oasis using Storie index soil suitable areas for agricultural productivity. The author reported that, Dakhla area is classified into tree grades. Furthermore more than 117 km2 are good capable and about 379.18 km2 are moderately capable for agricultural production as shown in Fig. 11.

7.2 Land Suitability Yousif (2014) applied Land Use Suitability Evaluation Tool (LUSET) by Yen et al. (2006) to evaluate the soil of Dakhla for crop suitability. This method depends on land qualities which are derived from land characteristics such as soil salinity dS/m1, drainage, carbonate content (%), slope, soil texture, organic matter %, etc. The current study used Land Use Suitability Evaluation. The author classified the crops into three groups; field, vegetable and fruit according to the requirements of the most commonly grown crops provided by Sys Ir et al. (1993), Fig. 12 showed the suitability crops for Dakhlas oasis. Therefore, the most maintainable land utilize was distinctive in each condition as indicated by the soil characteristics. In another study Fadl and Abuzaid (2017) have evaluated soil suitability for crops of Dakhla Oasis using Almagra model, which considered one of the most prevalent models in the world. This system is an automatized application of soil suitability model is based on a qualitative assessment of biophysical factors, soil variables and surrounding conditions affecting crop growth within MicroLEIS (De la Rosa et al. 1992; Abd-Elmabodet al. 2019). However, the authors applied this method to evaluate agricultural crop suitability in Dakhla Oasis. They selected, twelve crops as fellows; wheat, potato, maize, sunflower, cotton, soybean, watermelon, sugar beet, alfalfa, peach, citrus, and olive were selected to be evaluated. The authors showed that soils suitability for crops Dakhla are varied from place to another and the area has the following suitability high suitable (S2), moderately suitable (S3) and marginally suitable (S4) moderately suitable (S3), marginally suitable (S4) and not suitable (S5).

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Fig. 11 Land capability of Dakhla Oasis. Source Yousif (2014)

8 Conclusion The use of remote sensing, GIS and climate data technologies has become key factors when assessing an ecosystem. This study highlighted the variation of soil properties in Dakhla Oasis, and explained how to use them for optimal use under these conditions. This study shows that the soils of Dakhla Oasis are highly productive and suitable for most crops. The most predominant limiting factors are salinity, soil depth and topography. Dakhla Oasis needs to improve infrastructure and services that attract people for sustainable development. Development in the oasis lands is one of the solutions to overcome the problem of overpopulation around the Nile Valley and Delta areas. The Government’s decision to move towards increased land reclamation activities in the oases is therefore a good step towards sustainable development. Finally, we can clarify that Dakhla Oasis is a promising area for sustainable agricultural development where natural resources are available.

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Fig. 12 Land suitability spatial distribution for some selected crops in Dakhla Oasis. Source Yousif (2014)

9 Recommendation • Dakhla Oasis is a promising area for new urban communities and is suitable for attracting residents from the Nile Valley and Delta. Also, it is suitable for land reclamation projects as its soils are high capability for crop production. The expansion of agriculture in the oasis requires a precise understanding of the land

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Fig. 12 (continued)

and water resources for optimum use. A study of land suitability maps for Various crops in Dakhla Oasis help plan sustainable agriculture programs • Remote sensing and GIS provide accurate and geo-spatial information about land and water suitability for crop production in addition to water requirements for various crops. • Dakhla Oasis soils are suitable for most crops, so the area can be exploited in major agricultural projects. In addition, Dakhla Oasis could contribute to supply large quantities of grins crops such as wheat, thus reducing the food gap in Egypt.

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Fig. 12 (continued)

• Dakhla Oasis needs more effort to develop an efficient improvement of infrastructure, education, health and social services. Youth should also be encouraged to invest in this region in the agricultural and industrial sectors by facilitating access to credit. • The use of modern technology in agricultural production can be promoted by training small farmers and investors on the uses of modern technologies of agriculture.

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Remote Sensing and GIS for Land Use/Land Cover Change Detection in Dakhla Oasis Adel Shalaby and Hossam S. Khedr

Abstract Accurate change detection of land use provides the decision makers the base for more understanding of the effect of human and nature interactions and relationships. Three multispectral satellite images were used for tracking the land use land cover change in Dakhla Oasis in the Western Desert (Egypt). These images were Landsat TM (1988), Landsat TM (2003), and Sentinel 2 (2018). Change detection study was applied in two periods, the first period from 1988 to 2003, while the second period from 2003 to 2018. Study area was classified into five classes; built-up area, agricultural area, water bodies, sand dunes, and barren land. A significant increase was recorded in the total areas of agricultural land and built-up areas, while the water bodies slightly increased in the period concerned. The built-up land slightly decreased from the first period to the second period from 89 ha/year to 81 ha/year respectively. While the agricultural land annual rate highly increased from 913.9 ha/year in the first period to 1,648.9 ha/year in the second period. Keywords Land cover · Land use · Land use change detection · Remote sensing GIS

1 Introduction Egypt has two main deserts, the Western and the Eastern deserts. The Western Desert is the biggest desert, and covers more than half of the country area by 680.650 square kilometer, from the west of the River Nile to the east of the Libyan border. It is generally rocky desert, but the western part toward the Libyan border has a renown sandy desert know as the Great Sand Sea. The Western Desert is a chain of oases that have small agricultural areas and inhabited areas, extending from Siwa in the north-west toward Kharga in the southern direction. Land cover was defined by Di Gregorio and Jansen (2000) as the physical cover that could be observed on the surface of the earth. Land use, on the other hand, A. Shalaby · H. S. Khedr (B) Environmental Studies and Land Use Division, National Authority for Remote Sensing and Space Sciences, 23 Joseph Tito Street, El-Nozha El-Gedida, Cairo, Egypt © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_9

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indicates the results or production of human activities and interactions with land cover types. The population in Egypt is increasing with an annual rate of 2.8%, where it increased from 59 million in 1996 to 96 million in 2018, and has so far shows no definite signs of a slowdown. Urban expansion is an unavoidable procedure because of the rapid growth of population and economic development. The increase of builtup areas, which generally occurs at the expense of agricultural land, may lead to very bad ramification such as land degradation and desertification (Shalaby et al. 2004). The impact of the increase in population density leads to cumulative stress on soils, a reduction in soil per capita from 0.12 ha (1950) to 0.06 ha (1990) (Suliman 1991) and in 2009 reached to 0.04 ha (CAPMAS 2009). Therefore, it is essential to define the rate and the tendency of the land cover change for the development decision making in order to find rational land use policy (Shalaby and Tateishi, 2007). Accurate temporal change detection of land use/land cover of the earth surface offers the base for understanding the interactions and relations between people and nature(Lu et al. 2004). Singh (1989) described the digital change detection, it is the process of describing and/or determining changes in the land-use and land-cover areas based on multitemporal remote sensing data (). Trajectory classification is one of the mathematical methods used for detecting change, which have other five classes, containing segmentation, differencing, thresholding, regression, and statistical boundary. Each class has its own strengths and limitations. Therefore, each method should be thoroughly understood by users before starting change detection with Landsat time series (Zhu 2017).

2 Study Area 2.1 Location The study area is Dakhla Oasis, which lies in the middle of the Western Desert in the New Valley governorate as shown in Map 1. It lies between longitudes 28o 30\ and 29o 22\ east and latitudes 25o 29\ and 25o 55\ north. Study area elevation ranges between 209 m to 568 m as shown in Map 2.

2.2 Demographic Trend Dakhla Oasis includes about twenty-five main villages. Population of the Dakhla Oasis increased from 80,226 in 2006 to 87,933 in 2016. Kato et al. (2014) showed that, generally, the growth of population was very slow in Dakhla Oasis up to 1960 by 4,496. Then, the population increased suddenly untill 1976 by 25,070. This increase

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Map 1 Location of the study area

was three times more than the national population growth average. It could be explained by the inhabitants migration from outside the oases, which maybe related to the national settlement projects during the 1960s and 1970s such as New Valley Project.

2.3 Climate Dakhla Oasis climate is distinguished with a high level of solar radiation, hot and dry climate, no rainfall and high rate of evaporation. The United Nations Environment Program (UNEP 1997) used the aridity index and indicated that Dakhla Oasis has a hyper-aridclimate. Its annual precipitation is around zero mm. Basically, there are about 520 springs and ponds in Dakhla Oasis. However, many of these springs have dried out recently. The groundwater is withdrawn by pumping (Sefelnasr et al. 2014) Temperature: minimum temperature value of 5.47°C was recorded in January, while the maximum one of 37.8°C prevails during July. Rainfall: climatic data of the study area recorded that no precipitation in Dakhla Oasis during all of the year.

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Map 2 Digital elevation model of the study area

Relative humidity: The Relative humidity rates differ from month to another. The values ranged from 19.08% in May to 49.23% in December. The annual mean relative humidity was 30.8%. Wind velocity: climate data shows that, the wind velocity ranges from 2.76 to 3.61 m/s in November and May, respectively.

3 Materials and Methods The current study uses various kinds of multispectral satellite sensors for tracking and mapping the land use land cover and its changes that occurred. These sensors include Landsat TM (1988), Landsat TM (2003), and Sentinel 2 (2018) as shown in Map 3. These used images were obtained from the USGS earth explorer site. Table 1 shows technical specification of these satellites sensors. Image preprocessing

Remote Sensing and GIS for Land Use … Map 3 (A) Landsat TM image 1988, (B) Landsat TM image 2003, and (c) Sentinel 2 image 2018

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Table 1 Technical specifications of the used optical sensors Satellite

Sensor

Bands

Landsat

Thematic Mapper (TM)

Band 1—Blue

0.45–0.52

30

Band 2—Green

0.52–0.60

30

Band 3—Red

0.63–0.69

30

Band 4—NIR

0.76–0.90

30

Band 5—SWIR 1

1.55–1.75

Band 6—Thermal Infrared (TIRS) 1

10.40–12.50

Band 7—SWIR 2

2.08–2.35

30

Band 1—Coastal aerosol

0.443

60

Band 2—Blue

0.490

10

Band 3—Green

0.560

10

Band 4—Red

0.665

10

Band 5—Vegetation Red Edge

0.705

20

Band 6—Vegetation Red Edge

0.740

20

Band 7—Vegetation Red Edge

0.783

20

Band 8—NIR

0.842

10

Band 8A—Vegetation Red Edge

0.865

20

Band 9—Water vapor

0.945

60

Band 10—SWIR—Cirrus

1.375

60

Band 11—SWIR

1.610

20

Sentinel-2

Wavelength (micrometers)

Spatial Resolution (meters)

Acquisition date August 1988 & August 2003

30 120

August 2018

Procedures of image processing were applied using the ENVI 5.1 and ArcGIS 10.4.1 Software. Image processing could be categorized into Image pre-processing and image processing. A. Layer stacking Layer stacking is the process of combination of separated bands to form a single multispectral image file for further analysis. In this current study, it was applied using ENVI 5.1 software. This was followed by defining all bands wavelengthes according to the electromagnetic spectrum of each Landsat sensor. B. Geometric correction

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Geometric correction addresses the errors in the relative positions of pixels. The process of geometric correction and rectification involve the use of several wellknown ground control points (GCPs). These GCPs include road intersections, railways, buildings, etc. to be matched in the original rectified map and the image to be rectified. The images are then rectified to the UTM projection system (Universal Transverse Mercator). The image was rectified to the Universal Transverse Mercator (UTM) Zone 35 north with datum of WGS 84. C. Image sub-setting The images were investigated and it was found that the data set cover not only the study area, but also a great part of the western desert. Therefore, ENVI 5.1 software was used to subset the image by the vector that include the boarder of the study area. This process decreases the amount of digital data in order to speed up processing which is important when dealing with multiband data. Image processing Satellite image classification Image classification could be defined as the automatic process of classifying all the pixels of a digital image into particular land cover classes (Lillesand et al. 2003). Supervised image classification technique is a user-controlled process where pixels are given into specified land use classes based on pre-determined locations that collected previously from field, aerial photographs, and maps (Jensen 1996). Support Vector Machine (SVM) classifier was used in the current study for classifying different remotely sensed images. Comparative analysis that was done by Devadas et al. 2012 clearly revealed that the object-based SVM method resulted in overall classification accuracy (95%), while it was less using traditional pixel-based classification (89%) The post-classification change detection analyses describe and quantify the changes that occured in the same scene at different times. Change of land use classes area between three classified images was calculated using the post classification process. According to Hegazy and Kaloop (2015), the post classification analysis is very useful to identify the types of changes that happened in different classes of land use such as decrease in agricultural land or the increase in urban built-up area and so on.

4 Results 4.1 Main Land Use/Land Cover Classes An up to date land use/land cover map was produced based on the supervised classification (SVM) for multispectral Sentinel 2 image dated 2018. The studied area was

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classified into Five main classes; built-up land, agricultural land, sand dunes, desert and water bodies. A. Barren land The study area is considered as desert area, so the barren land class in the study area is represented by the desert. B. Agricultural land In Egypt, the main Land Use/Land Cover (LULC) is agriculture which is an important source of the Egyptian economy. Agricultural land in the study area is represented by cultivated land (already under cultivation), after supervised classification, visual interpretation using on screen digitizing were applied to improve the classification results and to identify fallow land. Reclaimed areas (barren land prepared to be cultivated for first time) were identified through visual interpretation, with the aid of Google earth images, since it have specific pattern on satellite images. C. Built-up land Built-up land class in the study area is represented by the residential areas or services areas like sewage treatment stations. D. Sand dunes Sand dunes are distributed in the whole study area, occupying 13,431 ha. E. Water bodies Areas covered by water i.e. drainage bonds

4.2 Land Use/Land Cover Change Detection The spatial-temporal changes in land use classes were detected over period of 30 years from 1988 to 2018 in Dakhla Oasis.

4.2.1

LULC During Years of the Study

In 1988, the main five LULC classes areas were 19,496 ha., 533 ha., 15505 ha. and 127 ha. for agricultural land, built-up land, sand dunes, and water bodies land, respectively and the rest of area was 397,682 ha for barren land. LULC classes could be ordered as follow; barren land (91.8%) > agricultural land (4.5%) > sand dunes (3.6%) > built-up land (0.1%) considering the areas in 1988, as shown in Map 4. In 2003, areas of LULC classes were 33,204 ha., 1,869 ha., 15,955 ha. and 5548.0 Fed. for agricultural land, built-up and sand dunes, respectively. Map 5 shows that, in 2003, LULC classes could be ordered as follow; barren land (88.1%) > agricultural land (7.7%) > sand dunes (3.7%) > built-up (0.4%) considering the areas in 2003.

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Map 4 Land use land cover in 1988

In 2018, areas of LULC classes were 57,938 ha., 3097 ha., 13431 ha. and 415 ha. for agricultural land, built-up, sand dunes and, water bodies respectively. LULC classes in 2018 showed the same order of 2003 and 1988 while the areas and percentage of each class were changed. LULC classes could be ordered as follow; barren land (82.7%) > agricultural land (13.4%) > sand dunes (3.1%) > built-up land (0.7%) considering the areas in 2018, as shown in Map 6. Figure 1 summarizes land use in the three years.

4.2.2

LULC Change Detection

Changes that occurred in the main classes of land use land cover in the study area were detected over the last thirty years from 1988 to 2018. It was divided into two periods, each one is about fifteen years. The first period is from 1988 to 2003, and the second is from 2003 to 2018. A. Changes of LULC from 1988 to 2003 The total areas of agricultural areas and built-up areas increased significantly, while the water bodies areas increased slowly in 1988–2003. The agricultural land area increased from 19,496 ha. in 1988 to 33,204 ha. in 2003. The built-up land area increased from 533 ha. to 1,869 ha., and the area of water bodies from 127 ha.

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Map 5 Land use land cover in 2003

to 326 ha. during the same period. Despite the agricultural area that showed the highest increase during 1988–2003, it was found that the urbanized areas expanded by 250.3% (of the built-up area in 1988) at the same time that the agricultural land increased by 70.3% (of the agriculture area in 1988). The increase in agricultural lands, built-up area and water bodies area meant a decrease in the barren land. In fact, the barren land area decreased from 397,682 ha. to 381,991 ha. with a difference of—15,690.5 ha., as shown in Table 2. B. Changes of LULC from 2003 to 2018 A significant increase was recorded only in the total areas of agricultural areas and built-up areas during the period from 2003 to 2018. The agricultural land area increased from 33,204 ha. in 2003 to 57,938 ha. in 2018, with a difference of 24,734.1 ha. Furthermore, the built-up land area increased from 1,869 ha. in 2003 to 3,097 ha. in 2018, with an increase amounted by 1,228.4 ha. Despite the agricultural area showed the highest increase in the period from 2003 to 2018, it was found that the built-up land expanded by 65.7% (of the built-up area in 2003) at the same time that the agricultural land increased by 74.5% (of the agriculture area in 2003). The increase that has been recorded in agricultural land, built-up area and water bodies were synchronized with a decrease in a barren land. The barren land decreased from 381,991 ha. in 2003 to 358,530 ha. in 2018, with a significant difference which amounted by—23,460.8 ha. as shown in Table 3.

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Map 6 Land use land cover in 2018

60000

Area (ha)

50000 40000 30000 20000 10000 0 Built-up land

1988 533

2003 1869

2018 3097

Agricultural land

19496

33204

57938

Sand dunes

15505

15955

13431

127

326

415

Water bodies

Fig. 1 Land use land cover area during years of the study

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Table 2 Land use area change from 1988 to 2003 1988

2003

(ha.)

(ha.)

Change of area (ha.)

%

Built-up land

533

1,869

1,335.2

250.3

Agricultural land

19,496

33,204

13,707.8

70.3

Sand dunes

15,505

15,955

450.0

2.9

Barren land

397,682

381,991

−15,690.5

−3.9

Water bodies

127

326

199.3

157.1

Change of area (ha.)

%

Table 3 Land use area change from 2003 to 2018 2003

2018

(ha.)

(ha.)

Built-up land

1,869

3,097

1,228.4

65.7

Agricultural land

33,204

57,938

24,734.1

74.5

Sand dunes

15,955

13,431

−2,523.8

−15.8

Barren land

381,991

358,530

−23,460.8

−6.1

Water bodies

326

415

88.9

27.2

C. Overall changes during the period of study from 1988 to 2018 The overall changes in the main LULC classes during the whole period of the study (1988–2018) as shown in Table 4. The increase of the total area of built-up land, agricultural land, and water bodies amounted by 2,563.6 ha., 38,441.9 ha. and 288.2 ha. respectively. This increase synchronized with a decrease in the total area of barren land that amounted by −3,9151.3 ha. as shown in Maps 7 and 8. The annual rate of built-up land slightly decreased from the first period to the second period from 89 ha/year to 81 ha/year respectively. While the agricultural land annual rate highly increased from 913.9 ha/year in the first period to 1,648.9 ha/year in the second period. The water bodies recorded an increasing annual rate in the first period by 13.3 ha/year, but in the second period, it recorded an increasing rate by 5.9 ha/year. This could be explained by the fact that the agricultural expansion during the first Table 4 Land use area change from 1988 to 2018 1988

2018

Change of area (ha.)

%

(ha.)

(ha.)

Built-up land

533

3,097

2,563.6

480.6

Agricultural land

19,496

57,938

38,441.9

197.2

Sand dunes

15,505

1,3431

−2,073.8

−13.4

Barren land

397,682

35,8530

−39,151.3

−9.8

Water bodies

127

415

288.2

227.1

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Map 7 Change of agricultural land area between years 1988: 2018

period (1988–2003) based on traditional flood irrigation technique, near and around the old agricultural land. In the scorned period (2003–2018) most of the agricultural expansion based on modern irrigation techniques and far away from the drainage network.

5 Conclusions This study revealed that, • Integration between geographical information and statistical data is efficient for the oasis societies study. • The visual interpretation using SVM supervised classification method increased the overall accuracy of the land use/cover classification. By combining remote sensing and GIS, the land use/land cover changes in Dakhla Oasis were detected. The agricultural land and urban settlements significantly increased, due to the increasing population and land reclamation. Generally, in terms of absolute land area, it was found that the annual rate of agricultural land growth was greater than the rate of built-up land sprawl during the period of study.

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Map 8 Change of built-up area between years 1988: 2018

It is also noted that, the built-up area increased with much higher rate in difference to the agricultural land that increased by 197.2% (of the agriculture area in 1988).

6 Recommendations • It is advised to apply modern irrigation methods such as pivot, sprinkler and drip irrigation to conserve the limited groundwater and to protect the soil form water logging and salinization. • Fixing sand dunes to protect agricultural land and infrastructure. • Using remote sensing and GIS to monitor land use/land cover periodically.

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References Central Agency for Public Mobilization and Statistics (CAPMAS) (2009) Statistical Year Book 2009. Cairo, Egypt, July Devadas R, Denham RJ, Pringle M (2012) Support vector machine classification of object-based data for crop mapping, using multi-temporal Landsat imagery. Int Arch Photogramm Remote Sens Spat Inf Sci 39:185–190 Di Gergorio A, Jansen LJM (2000) Land cover classification system (LCCS): classification concepts and user manual. For Software Version 1.0. FAO, Rome. ISBN 92-5-104216-0 Hegazy IR, Kaloop MR (2015) Monitoring urban growth and land use change detection with GIS and remote sensing techniques in Daqahlia governorate Egypt. Int J Sustain built Environ 4(1):117–124 Jensen JR (1996) Introductory digital image processing: a remote sensing perspective. Prentice Hall Inc., Upper Saddle River, 316 pp Kato H, Elbeih S, Iwasaki E, Sefelnasr A, Shalaby A, Zaghloul EA (2014) The relationship between groundwater, land use, and demography in Dakhla Oasis. Egypt J Asian Netw GIS-Based Hist Stud 2:3–10 Lillesand TM, Kiefer RW, Chipman JW (2003) Remote sensing and image interpretation. Wiley, New York Lu DS, Mausel P, Brondı´zio ES, Moran E (2004) Change detection techniques. Int J Remote Sens 25:2365–2407 Sefelnasr A, Gossel W, Wycisk P (2014) Three dimensional groundwater flow modeling approach for the groundwater management options for the Dakhla Oasis, Western Desert, Egypt. Environmental Earth Sciences, https://doi.org/10.1007/s12665-013-3041-4 Shalaby A, Aboel Ghar M, Tateishi R (2004) Desertification impact assessment in Egypt using low resolution satellite data and GIS. Int J Environ Stud 61(4):375–384 Shalaby A, Tateishi R (2007) Remote sensing and GIS for mapping and monitoring land cover and land-use changes in the Northwestern coastal zone of Egypt. Appl Geogr 27:28–41 Singh A (1989) Review article digital change detection techniques using remotely-sensed data. Int J Remote Sens 10(6):989–1003 Suliman MK (1991) Universities and Development of the Desert land in the ARE. The Second annual university conference, Cairo, 2–5 Nov 1991 UNEP (United Nations Environment Programme) (1997) World atlas of desertification, 2nd edn. UNEP, London Zhu Z (2017) Change detection using landsat time series: A review of frequencies, preprocessing, algorithms, and applications. ISPRS J Photogrammetry Remote Sens 130:370–384

Crop Diversification and Its Efficiency in Rashda Village, Dakhla Oasis Erina Iwasaki and Kenichi Kashiwagi

Abstract In an arid climate region, where available water is limited, one of the important strategies to optimize the production is to diversify their crop cultivation. This chapter analyses farmers’ diversification strategies focusing on crop production in Rashda village in Dakhla Oasis. Technical and scale efficiency of farms in Rashda of Egypt is investigated by using DEA (Data Envelopment Analysis) approach. Using cross section data of agricultural households collected from the household survey in Rashda in 2009, technical and scale efficiency were estimated in the first stage. As a second stage, the OLS model was estimated to find factors associate with higher efficiency. Results suggest the estimated efficiency scores of agricultural households in Rashda are generally low, where the majority of farms show less than 40% of technical efficiency. Yet, estimated results also suggest the level of output can be increased by 82.5%, 79.8% under the CRS, VRS specifications, respectively, with the current level of inputs. About 24.6% of farms can increase their production and productivity through increasing their inputs, while 24.1% can improve their productivity by reducing their inputs. While the crop diversification does not contribute to improve efficiency, the expansion of cultivation of water-saving crops such as dates is a positive factor for improving efficiency. Human capital accumulation, increase experience and intensification of family labor use would contribute to improve technical efficiency. These results imply that the simple diversification of crop production does not result in improved efficiency. The farmers who intensify in date fruits which is a high value crop, have highest score of efficiency. In contrast, the farmers who cultivate wheat, fodder crops along with rice demonstrate low efficiency, which is from household consumption side point of view a rational choice in order to secure the household’s basic food need.

E. Iwasaki (B) Faculty of Foreign Studies, Sophia University, Tokyo, Japan e-mail: [email protected] K. Kashiwagi Faculty of Humanities and Social Sciences, University of Tsukuba, Tsukuba, Japan e-mail: [email protected] © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_10

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Keywords Crop diversification · Household survey · Data envelopment analysis · Technical efficiency · Farmer · Egypt

1 Introduction Although agriculture is less commonly practiced in the villages in Dakhla Oasis, it still plays an important role in the household economy like in the villages along the Nile River. However, the farmers in Dakhla Oasis differ from those in the Nile River in that they depend on groundwater, which is discharged from the wells that are shared between farmers. The water quantity is fixed and distributed by water rotation. Therefore, the farmers must search for diverse strategies to optimize their production. In this chapter, we focus on one of the villages in Dakhla Oasis, Rashda village, to investigate the efficiency of cultivation based on the household survey data. The household survey in Rashda village was conducted as part of the rural household surveys in 19 villages conducted since 2005 by the joint research project between Hitotsubashi University and Central Agency of Public Mobilization and Statistics (CAPMAS). In Rashda village, a household survey was conducted in 2009 among 715 households living in the village.1 Among these households, 41% were cultivating land at the time of the survey. The following study in this chapter is based on the data from these samples of farm households. The efficiency of agricultural households in Rashda is investigated to identify the determinant factors to improve efficiency. We use these panel data to estimate farm-level technical and scale efficiency using the data envelopment analysis (DEA) approach to identify the factors determining the efficiency level. The remainder of the chapter is organized as follows. After reviewing the farming practices in the study village in Sects. 2 and 3 explains the model used in our analysis. Data collection for estimation is presented in Sect. 3.2. In Sect. 4, we present the empirical results and discussions, while Sect. 5 concludes the chapter.

2 Diversification of Farming Practices in Rashda Village 2.1 Crops in Dakhla Oasis The agricultural season is divided into two seasons. The first is the winter season from November to April–May. The second is the summer season from May to October. Like other villages in Dakhla Oasis, the most common crops in Rashda are wheat and 1 Fieldwork in Rashda was conducted at the end of 2009 to collect data using the questionnaire from

600 households living in the village. Additional households were sampled in the beginning of 2010 to collect data from the farmers in Irrigation District No. 3 in Rashda where intensive fieldwork has been conducted up to that time.

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Egyptian clover (birsim baladi) in winter, and rice and sorghum in summer, whereas dates and alfalfa (birsim hijazi) are perennial. Rice has been the preferred summer crop for many years, although it requires more water than any other crop in general and particularly in the oasis region with its high evaporation rate. Although water is not abundant in the oasis, there are good reasons for the choice of rice as a crop: e.g., it is the most profitable staple crop and it is well adapted to adverse summer conditions. Second, farmers are aware that growing rice is the best means to leach down the continuously accumulating salts in the soil. Third, leaving the land fallow during summer would facilitate salt accumulation, and, as a result, it is good for sensitive winter crops, such as wheat and Egyptian clover (Momtaz and Siddiq 1989: 280). Beadnell (1909) noted that rice has been grown for a long time in oases, and for good reason. Rice grows on land containing a proportion of salt and provides a periodical cleansing of the land, which would otherwise become so salty that it would adversely affect other crops grown on the same ground (Beadnell 1909: 214). However, in the New Valley governorate, rice production is forbidden by law to reduce the overdraft of water from aquifers. The possibility of rice production is subject to the decision of the Ministry of Water Resources and Irrigation, in coordination with the Ministry of Agriculture, which determines the surface area to be cultivated with rice annually before the rice season.2 Dates are one of the most important agricultural products in Dakhla Oasis. Date palms are suitable for dry and rainless areas, but they do not yield fruit unless their roots are well watered. For this reason, dates are best suited to oasis agriculture.3 Egyptian clover or birsim baladi (Trifolium alexandrinum L.) is the main forage cultivated in the winter season to feed cattle.4 It is a common crop in the Nile basin, but also in the Western Desert. It is used for a double purpose: i.e., livestock fodder and fertilizer. It is rich in nitrogen, which enhances the crop production from the soil. As such, many farmers use it as a half-yearly rotation crop. Egyptian clover grows quickly; thus, it can be cut four or five times in a season. It is used after rice cultivation to render the saline and poorly drained soil fertile. Compared with other forages, it uses water efficiently (Muhammad et al. 2014: 66). 2 See “Irrigation deals firmly with violators of rice cultivation rules” in the Egypt Independent, 15 July

2019 (http://www.egyptindependent.com/news); “Egypt cuts cultivation of water-intensive crop” in the Nieuwsbericht, 13 August 2017 (https://www.agroberichtenbuitenland.nl/actueel/nieuws). 3 There are many varieties of date palms, but in Rashda, and in the Western Desert in general, the most common varieties are Saidi and Tamar. Saidi dates are a popular variety in Egypt for their soft and sweet taste and are sold in markets mostly through the date factory operated by the Agricultural Cooperative in the town of Mut. Saidi dates are also used to make date paste, agwa, which is used for making sweets, such as maamul. Tamar is a variety usually eaten after sun drying, and mostly for home consumption. Hayani is also a common variety in Egypt, but it is rarely grown in Rashda village (Kato and Iwasaki 2016: 212). 4 There are five varieties of Egyptian clover in Egypt: misqawi, saidi, fahl, and khadrawi. In Rashda village, the most common variety is misqawi, which is also common in Lower Egypt, where there is abundant water in winter. Misqawi grows rapidly and can be cut four to eight times in a season (Kenneth and Mackie 1925: 13).

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70 60 50 40 30 20 10

2003

2001

1996

1998

1993

1987

1990

1985

1980

1977

1973

1975

1967

1969

1965

1961

1963

1955

1953

1942

1946

1925

1911

1820

0

Fig. 1 Years of establishment of wells (number of households) (2005) Source Rural Household Survey (2005)

Alfalfa or birsim hijazi is widely planted in the oases in the Western Desert and cultivated to provide green fed hay or silage for cattle. It is a water-intensive crop, but is preferred by large-scale farmers in the Western Desert for exporting to the Gulf countries as animal feed (Arafat and El Nour 2019). In Rashda village, alfalfa is planted for three consecutive years. Sorghum or durra is one of the oldest crops cultivated since ancient times and one of the most widely adapted forage crops to the arid regions.5 It is generally known as “the camel of crops,” because it does not need much water and other natural resources during cultivation.

2.2 Different Cultivations by Type of Well6 In Rashda, and in the oasis villages in general, cultivation depends on to access to wells because water is drawn from underground. In this regard, the New Valley project implemented during the late 1950s and the 1960s had a substantial impact on land use and cultivation. The importance of this project can be understood from Fig. 1. This figure shows the years of establishment of the wells to which farm households are attached. Most of the wells were constructed in the 1960s, which is when the households began cultivation. 5 Sorghum

has been found in the archaeological site at Nabta playa in the Western Desert, as far back as 8000 BC (Wasylikowa et al. 1996). 6 This section is based on Kato and Iwasaki (2016: 207—208).

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Table 1 Area (feddans) of land for cultivation of main crops (2008)

Winter

Crop

Government and local wells

Investment wells

Wheat

750

332

84

1166

Alfalfa (birsim hijazi)

360

285

200

845

Egyptian clover (birsim baladi)

400

89

Barley

Total

489

12

18

4

34

Fava beans (ful)

6

20

3

29

Egyptian lupin (tirmis)

3

2

5

Peas (bsila)

1

2

3

Onion Summer

Surface springs

Rice

4

14

150

12

30 150

Cow-pea (lubiya)

35

35

70

Sorghum

50

10

60

Maize

10

15

25

Note One feddan equals 0.42 ha Source Kato and Iwasaki (2016: 213)

During this project, the wells, called “government wells”, were drilled with a double aim: first, to increase the production of the staple crop—wheat—for food security; and second, to assist land reform under a socialist regime that aimed to improve the livelihood of Egyptian peasants after the July Revolution in 1952. Land attached to government wells is leased to the villagers on the condition that they are landless and in low-income households. According to an informant, this had a considerable effect on upgrading the living standards of households in Rashda. From the end of the 1990s, wells are dug under the “investment well” or “surface spring” schemes. Investment wells are exploited by one or several individuals (investors) under a scheme of the General Authority for Investment (al-Hay’a alAmma al-Istithmari), an affiliate of the Ministry of Investment. An individual who wants to start an agricultural business may dig a well after obtaining permission from this organization. By law, the depths of investment wells must be 300 meters, and the area of irrigation of each well is defined as 10 feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m). Surface springs (‘ain sathi) are shallow wells drilled with permission from the Land Reclamation Fund. They are individually or collectively owned and managed by the farmers. Their irrigated land is leased to cultivators by the government, which owns the land. By law, a surface spring’s irrigated area is defined as 10 feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m). The crops cultivated differ by type of well (Table 1). Alfalfa is the preferred crop in the New Valley governorate in general, but more so in districts irrigated by

166

E. Iwasaki and K. Kashiwagi

investment wells and surface springs. Dates are generally produced on land attached to local and investment wells. However, the land attached to government wells does not have palm trees. On such land, the main crops are rice and sorghum in summer, and wheat and Egyptian clover in winter, whereas alfalfa is a perennial crop. These crops are also cultivated on land attached to investment wells. In addition, vegetables, such as fava beans (ful), onions and cow-peas (lubiya), are grown there in winter.

2.3 Crop Rotation in the Government Well Irrigation Districts7 The major reason for the different crops on the land attached to government wells and other wells is that crops from government wells are managed by an agronomist attached to the agricultural cooperative. Each year a meeting with agronomists is held to decide which crops to cultivate. Under the supervision of the agricultural cooperative, the farmers of the government well cultivate the same crops under a crop rotation system. This is a system that has generally been used in the Nile basin, especially when rice cultivation was controlled by the government until the 1990s. According to this system, farmers hold three plots each in different subdistricts. Because rice cultivation requires permanent irrigation, and water flows for other crops must be controlled to avoid the overuse of water, crop rotation is necessary. The kinds of crops and their rotations are decided by the Directorate of the Ministry of Agriculture. One of the three subdistricts must cultivate alfalfa for three years, whereas two subdistricts participate in crop rotation as in Table 2. For this reason, crops are rotated between subdistricts every three years and six months. As Hansen (1975: 151) explains, crop rotation in the Nile basin is intended to combine the advantages of private ownership and small farmers’ initiatives with economies of scale in irrigation, soil preparation, financing, and trading, and the system gives individual farmers land in different parts of the area under common rotation. The three-year rotation system thus implies that farmers should be given land in three different places, each with a different crop. In this way, large areas can be grown with the same crop, whereas the individual small farmer on his three plots of land applies the same rotation that he would apply individually and will always have a food crop for his family, a feed crop for buffalos, and a cash crop for his expenses. Soil preparation, including ploughing and irrigation, may become more rational, taking advantage of economies of scale in these processes. Mechanization becomes possible, whereas seeding, weeding, fertilizing, and harvesting are left to the individual owner. Seeds and fertilizers are provided by the agricultural cooperative (Hansen 1975: 150).

7 This

section is based on Kato and Iwasaki (2016: 214).

Crop Diversification and Its Efficiency …

167

Table 2 Crop rotation in government well irrigation district no. 3 (2010–2012) South subdistrict

North subdistrict

West subdistrict

Summer

Winter

Summer

Winter

Summer

2012

Fallow land

Wheat

Rice

Egyptian clover

Alfalfa

2011

Sorghum (instead of rice)

Egyptian clover

Fallow land

Wheat

Alfalfa

2010

Fallow land

Wheat

Sorghum (instead of rice)

Egyptian clover

Alfalfa

2009

Alfalfa

Fallow land

Wheat

Rice

Egyptian clover

2008

Alfalfa

Sorghum (instead of rice)

Egyptian clover

Fallow land

Wheat

2007

Alfalfa

Fallow land

Wheat

Sorghum (instead of rice)

Egyptian clover

Winter

2.4 Diversification Strategy According to Land Size The diversification strategy of farmers can be understood in another way, by examining the crops by land size. The mean area of cultivated land in Rashda is 2.8 feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) among the farm households, which is much larger than the average in the Nile basin. Of the total landholders, 33% of them have less than two feddans of land, whereas 32% of the landholders have five feddans or more. A few farmers have large landholdings: the largest being 40 feddans, followed by one farmer with eight feddans, and another three farmers with six feddans. Table 3 shows the crops cultivated by farmers in Rashda according to their land size. For all the farmers, wheat is the most important crop, especially for the small landholders with less than one feddan. Rice is also an important crop, especially for the middle size landholders with 1–2 feddans of land. The crops are consumed by households, sold, or given to the landowner. Table 4 shows the structure of the usage of main crop production. Only a small number of farm households reported that they had produced vegetables or fruits other than dates. Half of the products are consumed by the households and contribute to maintaining the household consumption level. More wheat is consumed by households than rice or dates. Fodder crops—Egyptian clover and alfalfa—are also used for household consumption to feed their animals. Small cultivators with less than one feddan grow wheat and Egyptian clover, essentially for household consumption. In contrast, medium cultivators (with two feddans) and large cultivators tend to cultivate different crops for market or for the

71

45

39

36

39

14

1 feddan

2 feddans

3 feddans

4 feddans

5-9 feddans

10 feddans or above

Source Rural Household Survey (2009)

266

36

0.5–1 feddan

Average

14

Less than 0.5 feddan

Number of households

Table 3 Crops cultivated by land size (2009)

5.0

47.2

6.8

4.8

3.3

2.5

1.4

0.9

0.5

Total crop area (feddan) 6.0

12.3

10.3

11.5

8.3

7.5

14.6

17.3

12.6

42.1

32.5

31.2

37.1

44.3

39.1

45.9

53.6

50.0

Wheat

Percentage Rice

0.6

0.0

1.5

0.6

1.4

0.7

0.0

0.0

0.0

Maize

27.2

20.1

23.0

31.0

28.7

29.2

29.6

23.9

22.6

Birsim

5.5

9.0

6.4

4.4

3.6

7.8

3.5

6.1

9.5

Dates & other fruits

4.7

3.0

3.5

8.7

7.2

4.8

3.4

0.0

11.9

Other crops

92.4

75.0

77.1

90.2

92.7

96.3

99.6

96.2

100.0

Total

168 E. Iwasaki and K. Kashiwagi

Crop Diversification and Its Efficiency …

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Table 4 Crops consumed by households by land size (2009) Number of households Less than 1 feddan

1 feddan

2 feddan

3–4 feddan

5 feddan or above

Consumed by household

Given to landowner

Sold

Total

Rice

15

54.6

0.0

45.4

100.0

Wheat

45

78.5

4.4

17.1

100.0

Dates

10

35.9

0.0

64.1

100.0

Birsim

28

96.4

3.6

0.0

100.0

Straw

45

87.8

4.4

7.8

100.0

Rice

54

36.5

3.7

59.8

100.0

Wheat

108

62.6

4.9

32.5

100.0

Dates

23

45.8

10.9

43.3

100.0

Birsim

83

85.5

3.0

11.5

100.0

Straw

98

86.2

4.6

9.2

100.0

Rice

13

27.0

22.5

50.5

100.0

Wheat

38

36.9

17.5

45.6

100.0

Dates

9

29.2

15.3

55.5

100.0

Birsim

31

70.9

21.5

7.6

100.0

Straw

34

69.6

16.4

14.0

100.0

Rice

14

29.1

28.6

42.4

100.0

Wheat

34

35.3

30.7

34.0

100.0

Dates

8

35.9

8.3

55.8

100.0

Birsim

31

60.2

27.6

12.2

100.0

Straw

33

69.1

26.1

4.7

100.0

Rice

31

30.5

35.2

34.3

100.0

Wheat

52

33.8

28.8

37.4

100.0

Dates

33

36.4

18.4

45.2

100.0

Birsim

50

62.4

28.1

9.5

100.0

Straw

50

60.0

27.5

12.4

100.0

Source Rural Household Survey (2009)

landowners. For instance, the percentage of households that consumed their wheat among cultivators of less than one feddan was 78.5% whereas those with one feddan was 62.6%. In contrast, the percentage of cultivators with two feddans or more who consumed their wheat was no more than 36.9%. For the latter, the remainder of the wheat crop was sold at market or given to the landowners. Thus, it could be said that the diversification strategy differs between small-scale cultivators of one feddan or less, and medium- or large-scale cultivators on the decision to cultivate wheat which provides the essential food for households.

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3 Model and Data 3.1 Model A widely used method for measuring efficiency is DEA, which is a nonparametric linear programming approach originally proposed by Farrell (1957). The DEA shows how a decision-making unit (DMU) manages relative to others in the sample, and then it provides a benchmark for best-practice technology. This idea was extended by Charnes, Cooper, and Rhodes (CCR) (1978) to develop the first DEA model. The efficiency scores of individual DMUs are bounded between zero and one. The DMUs on the best practice frontier have an efficiency score equal to one. Less efficient DMUs are measured relative to the efficient ones, having a score less than one. The DEA models have been frequently applied to agricultural production due to their advantages. The first DEA model assumed constant returns to scale (CRS). Under this assumption, increasing the inputs result in a proportionate increase in output; however, this may not always be observed (Speelman et al. 2008). The assumption of CRS is only appropriate when all DMUs are operating at optimal scale, but some factors may cause some DMUs not to operate at optimal scale. However, Banker, Charnes, and Cooper (BCC) (1984) proposed an extension of the CRS-DEA model, having variable returns to scale (VRS). Assuming the VRS specification specifies that not all DMUs are operating at the optimal scale. The study of efficiency using DEA can be either output- or input-oriented. In this study, we choose the output-oriented DEA model where the estimated efficiency scores indicate how much each DMU should be able to produce more output compared with the best performers. Supposing there are N agricultural households using K inputs and producing M outputs. For farm i, input and output data are denoted by the column vectors x i , yi , respectively. The output-oriented CCR model can be written as: Max θ, θ,λ

s.t xi − XY ≥ 0, θ yi − Y λ ≥ 0, λ≥0

(1)

where θ is a scalar of the ith farm, λr is an N×1 vector of constants, X is a K×N matrix of inputs, and Y is a M×N matrix of outputs. The parameter θ is the overall technical efficiency score for the ith farm, having value between 0 to 1, where a value of 1 indicates the point is on the frontier. When the value of θ is 1, the farm is technically efficient. The linear programming problem (1) is solved N times, once for each farm in the sample, and then a value of θ is obtained for each farm. In the CRS-DEA model, the solution gives the frontier of fully efficient farms. The BCC model is the same as the CCR model above, but includes the convexity constraint, N1 λ = 1; thus, the output-oriented BCC model can be represented as

Crop Diversification and Its Efficiency …

171

follows: Max η, η,λ

s.t xi − Xλ ≥ 0, ηyi − Y λ ≥ 0, N 1 λ = 1, λ≥0

(2)

where η is a scalar of the ith farm. A value of η ranging between 0 to 1 is obtained for each farm by solving the linear programming problem (2). Equation (2) has a VRS specification which includes the convexity constraint, N1 λ = 1. Without this constraint, the DEA model will be the CCR model where farms are assumed to be operating at their optimal scale. We calculate the efficiency values of both the CRS and the VRS specifications and compare them to analyze the scale efficiencies of the sample farms. The VRS model allows calculating technical efficiency (TE) without the scale efficiency (SE) effects, which means that the CRS technical efficiency is decomposed into pure technical efficiency and SE. The scale efficiency is given by the ratio TECRS /TEVRS (Coelli et al. 2005). If the scale efficiency is equal to one, it suggests that the farm is operating at the optimal scale. Any changes in the scale results in inefficiency that may exist either due to increasing returns to scale (IRS) or decreasing returns to scale (DRS). As a second stage of this study, we select several explanatory variables that are expected to be potential determinants of technical efficiency. The model of technical efficiency could be specified as follows: TEi = β0 +

J 

β j Z ji + μi

(3)

j=1

where Z j (j = 1, 2, …, J) is the farm-specific variables that may affect technical efficiency, β i is an unknown parameter to be estimated, μi represents the error term. As for the variable Z h , we include the ratio of cultivation of crops, years of education, sex, age of the head of household, ratio of family labor to total labor. We use the ordinary least squares (OLS) regression for the estimation of the parameters of the model in Eq. (3). To examine the effect of crop diversification on technical efficiency, we use the Simpson index of diversification (SID), which is mathematically defined as: S I Di = 1 −

n 

Phi2

(4)

h

where Phi is the proportionate area of hth crop to the total cropping area for the ith farm household. This index ranges between 0 and 1. If this index closer to one, farmers adopt higher diversification. The value closer to 0 indicates more specialization.

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3.2 Data Table 5 presents summary statistics of the variables used for the estimation. We use Production as an output for the DEA model, which denotes the value of production of crops measured in Egyptian pounds (LE). The inputs used in the estimation include Land, Labor and Cost production. Land indicates total area used in agricultural production measured by feddan. Labor is the total number of working days of family and wage laborers. Cost production denotes the total cost for production of crops measured in Egyptian pounds. The variable Simpson diversification denotes the degree of diversification of crop cultivation. The ratio of each crop to the total cropping area, including wheat, dates, rice, alfalfa, and sorghum, are added in the independent variables. As for control variables, we include education, sex, and age Table 5 Summary statistics Variables

Observations

Mean

Standard deviation

Production (LE)

187

16582.0

64343.3

Land (feddan)

187

Labor (days)

187

339.8

56.7

Cost production (LE)

187

2900.0

12562.1

Simpson diversification

187

0.538

0.191

0

0.750

Ratio wheat cultivation

187

0.419

0.214

0

1

Ratio dates cultivation

187

0.069

0.150

0

1

Ratio rice cultivation

187

0.138

0.155

0

0.5

Ratio alfalfa cultivation

187

0.250

0.219

0

1

Ratio sorghum cultivation

187

0.007

0.042

0

0.3

Education household head (years)

187

5.749

5.446

0

16

Sex of household head (1 = male, 0 = female)

187

0.984

0.126

0

1

Age of household head (years)

187

27

82

0

1

Family labor ratio 187 Note LE indicates the Egyptian pound

6.667

54.7 0.993

33.363

12.2 0.077

Minimum

Maximum

60.0

828600.0

0.1

455.0

100 110.0

565 167800.0

Crop Diversification and Its Efficiency … Table 6 Frequency distributions of efficiency scores

173

Efficiency

CRS-TE

VRS-TE

SE

0.0 < Efficiency < 0.2

131

121

4

(70.1)

(64.7)

(2.1)

46

50

1

(24.6)

(26.7)

(0.5)

0.4 < Efficiency < 0.6

2

4

1

(1.1)

(2.1)

(0.5)

0.6 < Efficiency < 0.8

3

3

9

(1.6)

(1.9)

(4.8)

5

9

172

(2.7)

(4.8)

(92.0)

Mean

0.175

0.202

0.943

Standard deviation

0.177

0.212

0.153

Minimum

0.006

0.007

0.047

Maximum

1.000

1.000

1.000

0.2 < Efficiency < 0.4

0.8 < Efficiency < 1.0

Note Percentages are in parentheses

of the heads of households. The ratio of family labor to total labor, family labor ratio, is added to examine the effect of intensive use of family labor.

4 Empirical Results and Discussion 4.1 Empirical Results DEAP (Data Envelopment Analysis Program) software was used to solve the programs of (1) and (2) to estimate the efficiency scores.8 The average scores of the technical efficiencies were 0.175 (17.5%) and 0.202 (20.2%) under the CRS and the VRS assumptions, respectively. These results suggest that the level of output can be increased by 82.5% and 79.8% under the CRS and VRS specifications, respectively, using the current levels of inputs. The frequency distributions of the obtained efficiency scores are presented at Table 6. Under the CRS assumption, the estimated technical efficiency varies between a minimum of 0.6% and a maximum of 100%, whereas they lie between 0.7 and 100% under the VRS assumption. It should be noted that 70.1% of the sample farms have technical efficiency scores less than or equal to 20% and 64.7% under the CRS and the VRS assumptions, respectively. 8 The DEAP program is available from the Centre for Efficiency and Productivity Analysis (CEPA)

at the University of Queensland, Australia: https://economics.uq.edu.au/cepa/software.

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E. Iwasaki and K. Kashiwagi

Regarding the scale efficiency, our empirical results show that 51.3% of the sample farms were scale efficient. The percentage of agricultural households that had decreasing returns to scale was 24.1%, whereas 24.6% of them experienced increasing returns to scale. These results suggest that 24.6% of farms could possibly increase their production and productivity through increasing their inputs. About 24.1% of farms could improve productivity through reducing their use of inputs. Regarding the second-stage analysis for Eq. (3), the method of the estimation used was OLS regression. The estimated parameters and their robust standard errors are presented in Tables 7, 8, and 9. The estimated coefficient of Simpson diversification is negative and statistically significant for the VRS-TE model. These results suggest that diversification of crop Table 7 Estimated coefficients and robust standard errors of CRS and VRS models Variable

CRS-TE

Constant

−0.109

−0.039

−0.015

−0.168*

(0.083)

(0.083)

(0.101)

(0.101)

Simpson diversification

VRS-TE

−0.307***

−0.058 (0.082)

(0.110)

Ratio wheat cultivation

−0.174** (0.079)

(0.114)

Ratio dates cultivation

0.158

0.195

(0.161)

(0.169)

Ratio rice cultivation

−0.198**

−0.187*

(0.089)

(0.103)

Ratio alfalfa cultivation

−0.134**

−0.143*

(0.066)

(0.073)

Ratio sorghum cultivation

−0.473***

−0.477**

0.036

(0.166)

(0.190)

0.004*

0.004*

0.004*

0.005*

(0.002)

(0.002)

(0.002)

(0.002)

Age of household head

0.003**

0.002**

0.004**

0.003**

(0.001)

(0.001)

(0.001)

(0.001)

Sex of household head

0.076**

0.056

0.105**

0.076**

(0.035)

(0.039)

(0.042)

(0.031)

Family labor ratio

0.072***

0.127***

0.050*

0.122***

(0.025)

(0.034)

(0.027)

(0.032)

Education of household head

R2

0.031

0.138

0.109

0.110

No. of observations

187

187

187

187

Notes Robust standard errors are in parentheses. *, ** and *** indicate statistical significance at the 10, 5 and 1% levels, respectively

Crop Diversification and Its Efficiency …

175

Table 8 Estimated coefficients and robust standard errors of the CRS model Variable

CRS-TE

Constant

−0.075

−0.025

−0.095

−0.155**

−0.130*

−0.161**

(0.075)

(0.071)

(0.073)

(0.075)

(0.072)

(0.076)

Ratio wheat cultivation

−0.166**

−0.158**

−0.136**

(0.074)

(0.069)

(0.066) 0.313**

0.299**

0.311**

(0.142)

(0.146)

(0.144)

Ratio dates cultivation Ratio rice cultivation

−0.162*

−0.06

(0.088) Ratio alfalfa cultivation

(0.069) −0.138**

−0.064

(0.062)

(0.056) −0.448***

Ratio sorghum cultivation

−0.292**

(0.136)

(0.122)

Education of household head

0.004*

0.004*

0.004*

0.005**

0.005**

0.005**

(0.002)

(0.002)

(0.002)

(0.002)

(0.002)

(0.002)

Age of household head

0.003**

0.003**

0.003**

0.002**

0.002**

0.002**

(0.001)

(0.001)

(0.001)

(0.001)

Sex of household head Family labor ratio

(0.001)

(0.001)

0.082*

0.061

0.083**

0.055

0.046

0.056

(0.041)

(0.046)

(0.041)

(0.035)

(0.040)

(0.037)

0.101***

0.073***

0.076***

0.118***

0.106***

0.109*** (0.029)

(0.025)

(0.017)

(0.018)

(0.032)

(0.025)

R2

0.068

0.078

0.616

0.100

0.103

0.102

No. of observations

187

187

187

187

187

187

Notes Robust standard errors are in parentheses. *, ** and *** indicate statistical significance at the 10, 5 and 1% levels, respectively

production does not contribute to improve efficiency. Parameters of the intensification of wheat production, represented by Ratio wheat cultivation, are negative and statistically significant for the CTR-TE equations, whereas they are positive and not significant for the VRS-TE models. These results also suggest intensification of wheat cultivation would result in decreased efficiency. In contrast, the estimated coefficients of the intensification of cultivation of dates, denoted by Ratio dates cultivation, are positive and statistically significant for the CRS-TE equation. This suggests that the expansion of date production would improve efficiency. We found negative and significant estimates of the parameters of the intensification of cultivation of rice, alfalfa, and sorghum, as denoted by Ratio rice cultivation,

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E. Iwasaki and K. Kashiwagi

Table 9 Estimated coefficients and robust standard errors of the VRS model Variable

VRS-TE

Constant

−0.201** (0.100)

(0.096)

(0.101)

Ratio wheat cultivation

0.035

0.038

0.063

(0.113)

(0.104)

(0.106)

−0.143

−0.221**

Ratio dates cultivation Ratio rice cultivation

−0.155

−0.196*

−0.143

−0.204**

(0.086)

(0.088)

0.232

0.206

0.236

(0.151)

(0.157)

(0.153)

−0.152*

(0.102)

(0.089) −0.156**

Ratio alfalfa cultivation

−0.136*

(0.075)

(0.076) −0.476***

Ratio sorghum cultivation

−0.441***

(0.150) Education of household head

0.005*

Age of household head

(0.141)

0.004

0.004*

0.005*

0.004*

0.005*

(0.002)

(0.002)

(0.002)

(0.002)

(0.002)

(0.002)

0.003***

0.004***

0.004***

0.003**

0.003***

0.003***

(0.001)

(0.001)

(0.001)

(0.001)

(0.001)

(0.001)

Sex of household head

0.106***

0.082**

0.106***

0.090**

0.070*

0.091***

(0.037)

(0.037)

(0.033)

(0.037)

(0.039)

(0.036)

Family labor ratio

0.094**

0.067***

0.070*

0.117***

0.087***

0.093** (0.038)

(0.039)

(0.025)

(0.041)

(0.038)

(0.028)

R2

0.050

0.063

0.047

0.074

0.081

0.070

No. of observations

187

187

187

187

187

187

Notes: Robust standard errors are in parentheses. *, ** and *** indicate statistical significance at the 10%, 5% and 1% levels, respectively

Ratio alfalfa cultivation and Ratio sorghum cultivation, respectively. Expansion of the cultivation of rice, alfalfa, and sorghum has a negative impact on efficiency. For the control variables, the coefficients of education and age of the household head are all positive and statistically significant. These results suggest that human capital accumulation and increase in experience have positive effects on efficiency. Whereas some parameters are not significant, the positive and significant estimate of the coefficient of the sex of the household head suggests that male-headed households are more efficient than female-headed households. The coefficient of the ratio of family labor, represented by Family labor ratio, is positive and significant. This suggests that intensification of family labor use has a positive impact of improving efficiency.

Crop Diversification and Its Efficiency …

177

4.2 Discussion Our empirical results imply that the simple diversification of crop production does not result in improved efficiency and the intensification of water-using crops, including rice, alfalfa, and sorghum, has a negative effect on efficiency. However, intensification of water-saving crops, such as dates, contributes to increased efficiency. Then why do farmers diversify their crop cultivation despite its low efficiency? Obviously, the cultivation regulation in the government well districts, as discussed in Sect. 2, is a determinant factor influencing the farmers’ behavior on crop choice. However, this is for the government well districts, but not all the farmers are bound to this regulation. Moreover, the crop decisions in the government well districts are taken by the farmers’ meeting although under the supervision of the Ministry of Agriculture, so that the decisions are understood as the farmers’ choices. How can we understand the farmers’ behavior then? One way is to take Table 10 summaries of the farmers’ characteristics of those with high and low efficiencies using the efficiency scores obtained from our empirical analysis. There are clear efficiency differences between the farmers according to their diversification strategies. In fact, efficient farmers with scores higher than 80% planted more date trees on an average 29.1% of their cultivated land compared with only 5.3% of the farmers with an efficiency less than 20%. Farmers with very low efficiencies of less than 20% are more inclined to cultivate rice, wheat, and fodder crops that provide essential food for their households, their cows, and their sheep. It is noted that most of the farmers with low efficiencies tend to produce crops for household consumption, which is consistent with our earlier observation in Sect. 2. Thus, small-scale farmers’ preferences on crop cultivation to grow more rice and fodder crops, despite their low values and water intensities, could be understood from the consumption side—that the household consumption perspective is rational to secure their basic need for food.

5 Summary and Conclusions This paper investigates the technical and scale efficiency of agricultural households in Rashda village in Dakhla Oasis to identify the determinant factors to improve efficiency. It also examines the effect of crop diversification on technical efficiency. We conducted the survey of agricultural households in Rashda during 2009 in collaboration with CAPMAS to collect micro-data of agricultural households. Using these panel data of inputs and output, farm-level technical and scale efficiencies are estimated by the DEA approach in the first stage. In a second-stage analysis, the OLS model was used to estimate the effects of factors associated with efficiency. Empirical results suggest the average scores of technical efficiencies was 17.5% under the CRS assumption, whereas it was 20.2% under the VRS assumption. The estimated efficiency scores of farms in Rashda were generally lower, but they suggest

131 131 131 131 131

Maize

Fodder

Date fruit

Straw

Others

Production (LE)

120 6

Straw

Other 98

108

Fodder

Wheat

0

Other fruits

60

41

Date fruit

Rice

6 6

Vegetables

130

Wheat

Maize

67

Rice

Total

131

Wheat

Cultivated area (%)

Crops consumed by household (%)

131 131

Rice

Land size (feddan)

2.8

3,344

1,949

85.8

79.3

79.2

40.9

42.5

57.3

46.1

28.2

100.0

2.6

6.3

5.3

27.0

1.0

43.4

14.5

42

22

4

48

37

2

21

1

0

49

27

51

51

51

51

51

51

51

51

Obs

8,110

4,571

30.3

62.1

56.0

7.6

21.3

100.0

39.6

28.8

100.0

3.4

13.8

9.4

20.9

0.0

39.9

12.6

9.2

Mean

0.2 < Efficiency < 0.8

Obs

Mean

0.0 < Efficiency < 0.2

Table 10 Summary table of crop diversification by efficiency score (CRS-TE)

4

2

2

3

3

1

3

1

0

4

2

5

5

5

5

5

5

5

5

Obs

(continued)

38,535

1,800

18.8

68.3

44.4

5.6

28.8

15.2

26.0

31.3

100.0

18.0

7.1

29.1

15.8

0.0

22.1

7.9

98.3

Mean

0.8 < Efficiency < 1.0

178 E. Iwasaki and K. Kashiwagi

Source Rural Household Survey (2009)

Table 10 (continued)

3 5 32 0 16 12 2 131

Maize

Vegetables

Date fruit

Other fruits

Fodder

Straw

Other

Total

3,723

5,242

7,500

2,217

3,991

3,720

1,253

51

4

27

20

1

19

0

0

Obs

25,728

7,250

9,897

13,703

15,000

15,036

Mean

0.2 < Efficiency < 0.8

Obs

Mean

0.0 < Efficiency < 0.2

5

2

1

1

1

3

1

0

Obs

220,408

8,100

28,000

12,500

180,000

213,867

66,000

Mean

0.8 < Efficiency < 1.0

Crop Diversification and Its Efficiency … 179

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E. Iwasaki and K. Kashiwagi

that the level of output can be increased by 82.5% and 79.8% under the CRS and VRS specifications, respectively, using the current levels of inputs. Less-efficient farms exist, whereas more than 90% of farms are no more than 40% efficient. The results of the scale efficiency scores suggest that more than half of the farms are scale efficient. More than 24% of the sample farms could possibly increase their production and productivity through increasing their inputs. About 24.1% of farms could improve efficiency through reducing their use of inputs. Regarding the factors associated with increasing efficiency, the results of the OLS estimation suggest a positive effect of the intensification of dates, human capital accumulation and increased experience on technical efficiency. Neither the crop diversification nor the intensification of wheat, rice, alfalfa, and sorghum have positive impacts on efficiency. These results imply that the simple diversification of crop production does not result in improved efficiency and the intensification of water-using crops including rice, alfalfa and sorghum have a negative effect on efficiency. However, intensification of water-saving crops such as dates contribute to increased efficiency. Human capital accumulation, increased experience and intensification of family labor use contribute to improved efficiency. Then why do farmers diversify their crop cultivation, despite its low efficiency? The result suggests that the farmers who intensify their production on high-value crops like dates have the highest efficiencies. In contrast, the farmers who cultivate wheat and fodder crops along with rice demonstrate low efficiency. Thus, from a production perspective, it is recommended to intensify planting dates as a profitmaximizing strategy. It would also be an advantage for the sustainability of water and agriculture in the oasis. However, farmers, mostly small-scale cultivators, prefer to grow more rice and fodder crops despite their low efficiencies and water intensity. This could be understood from the consumption side; i.e., from a household consumption perspective, it is rational to secure the household’s basic food needs.

6 Recommendations Irrigation water is a limiting factor in the oasis region due to the shortage in water resources. Therefore, there is a dire need to determine the adequate quantities of crops to reach the highest levels of crop production. The results of our empirical analysis show that the most efficient way of cultivation is to intensify the cultivation of date fruits. However, the cropping decision should simultaneously consider the requirements for basic food for the household and its animals. It should be noted that the level of agricultural output could be increased by 79.8 and 82.5% with the current levels of inputs and given technology. More than 24% of farms could increase their production and productivity by increasing their inputs under the current crop cultivation patterns. About 24.1% of farms could improve their efficiencies by reducing their input use.

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Further study is required on the farmers’ consumption behavior to determine the cropping pattern suitable for household welfare to secure basic foods. Also, further study is required to clarify the water quantity available according to the type of well, and the water requirement of each crop to reach the highest economic returns with water rationalization.

References Arafat N, El Nour, S (translated by Mariam Ibrahim) (2019) How Egypt’s water feeds the Gulf. https://madamasr.com/en/, 19 May 2019 Banker RD, Charnes A, Cooper WW (1984) Some models for estimating technical and scale inefficiencies in data envelopment analysis. Manage Sci 30(9):1078–1092 Beadnell HJ Llewellyn (1909) An Egyptian Oasis: An account of the Oasis of Kharga in the Libyan Desert, with special reference to its history, physical geography, and water supply. John Murray, London Charnes A, Cooper WW, Rhodes E (1978) Measuring efficiency of decision making units. European J Opera Rese 2:429–444 Coelli TJ, Rao DSP, O’Donnell CJ, Battese GE (2005) An introduction to efficiency and productivity analysis (2nd ed.). Springer, New York Farrell MJ (1957) The measurement of productive efficiency. J Roy Stat Soci Series A 120:253–290 Hansen B (1975) Chapter 6: Basic characteristics of Egyptian agriculture. In: Hansen B, Nashashibi K (eds) Foreign Trade Regimes and Economic Development: Egypt. NBER. http://www.nber. org/books/hans75-1 Kato H, Iwasaki E (2016) Rashda: The birth and growth of an Egyptian Oasis village. Brill, Leiden and Boston Kenneth PB, Mackie, WW (1925) Berseem or Egyptian clover (Trifolium Alexandrinum): A preliminary report. Agricultural Experiment Station, Berkeley, CA. http://catalog.hathitrust.org/Record/ 100089496 Momtaz A, Siddiq EA (1989) Extending rice cultivation to new areas in Egypt. In: Rice farming systems. New directions. International Rice Research Institute. Proceedings of an International Symposium 31 January–3 February 1987, Rice Research and Training Center, Sakha, Egypt. http://pdf.usaid.gov/pdf_docs/pnabd499.pdf Muhammad D, Misri B, al-Nahrawy M, Khan S, Serkan A (2014) Egyptian clover (Trifolium alexandrinum), king of forage crops. Food and Agriculture Organization of the United Nations, Regional Office for the Near East and North Africa Cairo Speelman S, D’Haese M, Buysse J, D’Haese L (2008) A measure for the efficiency of water use and its determinants: a case study of small-scale irrigation schemes in north-west province, South Africa. Agric Syst 98:235–243 Wasylikowa K, Schild R, Wendorf F, Krqlk H, Kubiak-MAR-TENS L, Harlan JR (1995) Archaeobotany of the Early Neolithic site E-75-6 at Nabta Playa, Western Desert, South Egypt (preliminary results). Acta Palaeobotanica 35(1):133–155

Hydrological Aspects and Water Resources

Hydrologeological and Hydrological Conditions of Dakhla Oasis Salwa F. Elbeih and Elsayed A. Zaghloul

Abstract Irrigation, domestic and industrial water requirements are increasing due to the population growth. The flood irrigation practices and the low water-use efficiency are the main obstcals for the potential for agricultural expansion. This chapter reviews previous investigations concerning the hydrogeologic conditions of the deep groundwater aquifer systems in Dakhla Oasis. In addition, it highlights distribution of drainage networks in the depression and the different lakes and ponds in the oasis and how their water is utilized. At the end of the chapter a number of recommendations are added to help in the better and efficient usage of the available water resources that will help in the development of the oasis and attract more investment and jobs opportunities for youth and young investors. Keywords Nubian Sandstone aquifer · Aquifer geometry · Water quality · Drainage water · Irrigation system

1 Introduction Egypt’s Nile water source is under increasing stress due to over populations and the developmental projects. Irrigation demands are increasing and the domestic and industrial water needs reqirements are also increasing due to the population and industrial growth. Although, the Nubian Sandstone aquifer is a non-renewable aquifer, it holds large volumes of freshwater storage, estimated by Ezzat (1974) to be of 2 × 1014 m3 , but could not be sufficient to provide a groundwater resource for sustainable development in the Western Desert and Egypt as well. S. F. Elbeih Engineering Applications and Water Division, National Authority for Remote Sensing and Space Sciences, 23 Joseph Tito st., El-Nozha El-Gedida, Cairo, Egypt e-mail: [email protected]; [email protected] E. A. Zaghloul (B) Geological Applications and Mineral Resources Division, National Authority for Remote Sensing and Space Sciences, 23 Joseph Tito Street, El-Nozha El-Gedida, Cairo, Egypt e-mail: [email protected]; [email protected] © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_11

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Sustainable development and agricultural progress in Dakhla Oasis have been lagging behind expectations. The flood irrigation practices and poor water-use efficiency has negative impacts on the agricultural sustainable developmental projects. Most of the irrigation canals and ditches in the oasis are open and unlined. This means that seepage and evaporation in these canals increase the water loss. Drainage systems are not working efficiently in many places, causing water logging, soil degradation and salinity problems. Thus the sustainable water management in Dakhla Oasis and in the New Valley is an issue of prime concern. New Valley Project was a part of the socialist land reforms that aimed to integrate rural development with land reclamation schemes (Kato and Iwasaki 2016). The specific objectives of this chapter is to review the previous investigations of the hydrogeologic conditions of the deep Nubian Sandstone aquifers in the Dakhla Basin (Fig. 1), including: groundwater aquifers, litho-stratigraphic units, geometry, aquifer boundaries, hydraulic parameters, potentiometery, regional flow direction, water quality, age dating, sustainable and the sustainable and economic deep groundwater aquifer. In addition, a review on the irrigation system and drainage ponds are highlighted.

Fig. 1 Location of Dakhla Oasis (DEM of the SRTM-03 [USGS 2004; NASA 2005])

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187

2 Climate The study area is located in the most arid belt in Egypt as a part from the Great Sahara. The annual rainfall is less than 20 mm/year. Dakhla Basin does not receive surface recharge to increase the groundwater potentiality of the main Nubian Sandstone aquifer and it may receive a sort of base flow from adjacent groundwater basins in Libya, Chad and Sudan.

3 Geologic Setting The Nubian Sandstone section covering approximately 2 million km2 in the northeastern portion of the Great Sahara and has been estimated to contain at least 50,000 km3 of groundwater (Thorweihe 1990). It rests uncomfortably upon the Crystalline Pre-Cambrian basement rocks which are exposed in the south, and southwest. The Bir Tarfawi uplifted basement rock (mainly Granite) divided the Western Desert into two basins: the Dakhla Basin (Fig. 3) in the west and the Kharga Depression in the east. The Nubian aquifer system in the Dakhla Basin consists of four water-bearing horizons (A, B, C and D) separated by a thin shale layer (Fig. 2) and the total thickness of the aquifer ranges from 400 to 3000 m.

Fig. 2 Geological map of Dakhla Oasis (Modified after CONOCO 1987; Hewaidy et al. 2017; Mansour et al. 1982)

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4 Hydrologeological Conditions The aquifer consists of alternating beds of sandstone (70%, shale and clay 30%). The shale and clay beds are laterally discontinuous and of varying thickness. The Nubian Sandstone succession increases in thickness from 200 m to 700 m in East Oweinat area, 300 m to about 1,500 m in Dakhla Oasis. Hydrogeological maps for Dakhla Oasis have been updated based on field and previous work (ASRT 2016) (Figs. 3 and 4).

4.1 The Aquifer Geometry The Nubian Sandstone basin is tectonically controlled by a group of regional faults and is divided into different sub-basins. The Dakhla Basin is hydraulically connected with the Kufra basin in Libya, Tebesti-Ennedi Mountains in Chad and Sudan (Fig. 5). The Nubian aquifer system, as a multi-layered artesian aquifer, is classified by Ezzat

Fig. 3 Generalized section of the Nubian Sandstone aquifer of Dakhla Depression (Modified after Heinl and Thorweihe 1993)

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Fig. 4 The Nubian Sandstone Aquifer System (after Salem and Pallas 2001)

(1974), into four horizons; A, B, C and D but hydraulically it behaves as one aquifer system. It contains large volumes of fresh water (less than 1000 ppm). The base of the aquifer is formed of two layers, the lower one is the surface of the weathered basement rocks in the south while the upper boundary of the aquifer is exposed at the surface south of Dakhla Depression where the aquifer is unconfined. To the north, it disappears under a thick cover of the Upper Cretaceous-Eocene complex of shale of Dakhla Formation and the carbonate rocks of the Tarawan Formation (Fig. 3). The thickness of the fresh water bearing unit decreases sharply north of lat. 29˚ N until it dissapears at the fresh/salt water interface. Hussein and Ghoubachi (2017) classified the subsurface section into a group of geoelectric layers that are divided into a surface layer, a clay zone, a dry sandstone zone and a saturated sandstone layer. They mentioned that the resistivity of the water

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Fig. 5 Extent of the Nubian aquifer system that shows the elevation of the basement surface and the structural basins (after Hesse et al. 1987). Pink areas are locations of groundwater discharge

bearing layer (D) decreases (Fig. 6) from SE (41.8 Ohm m) to NW (20.2 Ohm m) and its lower boundary was not recorded. A normal fault (F) was inferred.

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Fig. 6 Geoelectric cross section E-É (after Hussein and Ghoubachi 2017)

4.2 Aquifer Recharge During the pluvial periods, groundwater recharge occurred both at the exposed sandstone rock units (Hesse et al. 1987) on the surface. The aquifer recharge occured during the pluvial periods that prevailed during the past 450 kyr BP, with the last pluvial period occurred between 9.5 to 4.5 kyr BP and 25 to 40 kyr BP (Hesse et al. 1987). Widespread local rainstorms recently recharged the shallow horizons of the aquifer where measured C14 exists (Haynes et al. 1987).

4.3 Aquifer Potentiometry and Pattern for Groundwater Flow The potentiometric map modified by Ezzat (1974) indicates that the groundwater table is 145 m in Dakhla Oasis. The regional groundwater flow model developed by Ebraheem et al. (2004) indicated that the drawdown in the next 100 years will have its maximum value in the central part of Dakhla Oasis (West of Mut City).

4.4 Groundwater Quality The recharged fresh water during the pluvial periods flushed out the salt contents down dip northward to its present fresh—salt water interface north of Siwa—Qattara Depressions. In the Dakhla Basin, the salinity ranges from 200 ppm in the lower horizon to more than 1000 ppm in the upper horizon. Based on the Water Quality Index (WQI), 38% and 36.6% of Dakhla Oasis is within the poor water category for

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Fig. 7 Simplified conceptual model with distributed recharge along the transect (Patterson et al. 2005)

drinking purposes according to the Egyptian and WHO standards, respectively. Moreover, most of the groundwater wells were of the best quality for irrigation in terms of salinity (less than 2000 mg/L) (El-Zeiny and Elbeih 2019).

4.5 Nubian Sandstone Age Dating The recent age dating of the Nubian aquifer system confirmed that groundwater reaches ages of hundreds to thousand years covering several pluvial and interpluvial periods. According to Patterson et al. (2005), the geometry of the aquifer is represented by a triangle (Fig. 7). It can be shown from the triangle, that the age of the groundwater is a function of depth.

5 Irrigation and Drainage System in Dakhla Oasis Flooding irrigation system in the depression is considered one of the main reasons for water consumption in agricultural operations. This system is based on flooding the cultivated areas with water for long time durations during irrigation. Thus, a large amount of water leaks during irrigation.

5.1 Drainage Network in the Depression Drainage networks are one of the main factors influencing the distribution of ponds in the depression. Accordingly, drainage networks and main ponds in Dakhla Oasis are

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basically connected with the early stages of agricultural reclamation at the beginning of the 1970s. This drainage system is related to the traditional flooding irrigation system that represents more than 85% of the irrigation system. On the other hand, recent trends in irrigation do not depend on drainage networks only. Drainage of surplus water takes place by transferring water through the networks to the ponds using pumping stations. Drainage networks differ according to their rank, some of them are main and others are secondary. Some of these drains are full of grass which makes it difficult for water flow and hence water infiltrates to the ground before reaching the pumping station. This leads to fluctuation in water levels inside the ponds and sometimes some ponds are empty of water due to little or no surplus water in it in addition to evaporation processes. The total length of drains in Dakhla Depression is 285.3 km in 2014 and the number of the main and secondary drains are 196 distributed throughout the whole depression (Table 1 and Fig. 8). Area of cultivated land served is 39,000 acre (representing 55.5% of the cultivated land of the depression). This means that more than 50% of the cultivated lands in Dakhla Depression do not depend on draining the excess water in the drains but depend on the surrounding lands which do not have a drainage network. Lengths and number of drains fluctuate in the depression where there are 47 drains with a length of 67.1 km (about 23.52%) from total drains length in the oasis. Also, in West Mawhub area, the number of drains is 30 with a total length of 62 km (21.73% from total drains length) (Abu Zeid 2015). Table 1 Distribution of drainage network in Dakhla Depression in 2014 District

No. of Drains

Length (km)

%

Area served (Acre)

%

Mut

47

67.1

24.089

6650

17.43

Maasara

25

32

11.488

2600

6.82

Ismant

6

Rashda

22

Budukhlu

9.8 26

3.518

800

2.10

9.334

2750

7.21

3

5.6

2.010

1500

3.93

Hindaw

14

13.6

4.882

1400

3.67

Gadida

5

12.15

4.362

2250

5.90

Mushia

6

5.9

2.118

825

2.16

Qalamun

6

5.5

1.975

725

1.90

Qasr

5

6.85

2.459

1400

3.67

Mawhub

6

9.2

3.303

2750

7.21

Ezab al Qasr West Mawhub Balat Teneida Total

1 30 6

1.75 62 13.85

7

7.25

189

278.55

0.628

500

1.31

22.258

8000

20.97

4.972

3500

9.17

2.603 100

2500 38,150

6.55 100

Source Drainage Administration in Dakhla—Unpublished data and field investigations 2013

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Fig. 8 Distribution of drainage network and area served in Dakhla Oasis in 2014. Source See Table 1

5.2 Drainage Ponds in Dakhla Oasis Drainage ponds in Dakhla Oasis are formed due to agricultural operations where water is produced and consumed within the agricultural ecosystem. These ponds reflect the different agricultural policies in water management; crop patterns and irrigation systems. Excess water, from the need of plants, is discharged into these ponds with excess salts, in addition to the discharge of excess water from soil washing. Agricultural drainage ponds are found in two main areas: the first in the middle of the depression, and the second in the western side of the depression (West Mawhub). There is one main pond in the western extension of the depression at West Mawhub area. This pond benefits from the drainage of approximately 8000 acres from the total cultivated area in the region. The rest of the drainage ponds, which are four main ponds, are found in the middle of the depression, which includes Mut, Qalamun, Rashda and West Mawhub ponds (Table 2).

5.2.1

Mut Drainage Pond

Mut pond is located at latitude 25˚ 32´ 12´´ North and longitude 28˚ 57´ 11´´ East on the main Dakhla—Farafra road, six kilometers Northwest of Mut (Fig. 9). It lies in the lowlands and is surrounded by a rickety bridge width of about 2 meters and works as a basin to prevent the outflow of water. It is one of the main tourist attractions in the area. The excess water is distributed from the land inside the Mut area and around the pond through a network of major banks and branches with lengths of

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Table 2 Drainage Ponds in Dakhla Oasis (Drainage Administration in Dakhla—Unpublished data and field investigations 2013) Pond Name

Usage

East

North

Pond Area (Acre)

Average depth (m)

West Mawhub

Agricultural drainage

28 ˚35´ 25´´

25 ˚52´ 23´´

800

2

Mut

Mixed (Sanitary and agricultural drainage)

28 ˚57´ 11´´

25 ˚32´ 12´´

730

2.5

Rashda

Sanitary drainage

28 ˚54´ 15´´

25˚ 34´ 14´´

200

3

Qalamun

Agricultural drainage

28˚ 55´ 47´´

25 ˚32´ 43´´

67.1 km. The number reaches 47 banks; therefore, they serve an area of 6650 acres of cultivated lands in the region. That pond differs from the rest of the drainage ponds in the region in that it is higher in elevation compared with the surrounding lands. Surplus water from the drainage of cultivated lands is drained through different ways in Dakhla Oasis. One of these ways is the Mut pond. Mut pond is where agricultural and sanitary drainage water is collected. Drainage ponds were constructed at higher levels compared to the level of agricultural lands and banks. This causes the banks to collapse in case of an increase in the level of sewage and the agricultural lands get submerged with this water in case of pumping stations failure. From a field visit in October 2013 to the lake, the following observations were recorded: • Water levels in Mut pond reached the minimum levels • Areas suffering from water collection (ponds) are found in topographically high lands while cultivated areas are at the lower levels and pumping stations are used to lift the drainage water to the ponds. • Quantities of agricultural drainage water are large and are unexploited. • Vegetation inside the ponds is large and wide and reduces large areas of the water bodies without exploitation. • Sand dunes encroachment plays an important role in covering the ponds, increasing sedimentation rates and reducing water column with increased evaporation rates. • No water budget was estimated for the cultivated crops • Wastewater treatment plants were used for the development of oily and woody forests.

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Fig. 9 Mut Drainage pond

5.2.2

West Mawhub Drainage Pond

West Mawhub Pond (Fig. 10) is located between coordinates 25˚ 52´ 23´´ North and for 28˚ 35´ 25´´ East near the northern edge of the depression. Drainage of West Mawhub agricultural lands, estimated to be 8000 acres, take place inside the pond.

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Fig. 10 West Mawub drainage Pond

Drainage takes place through up to 30 main and secondary drains with a total length of 62 km through a lift station to the pond.

5.2.3

Qalamun Drainage Pond

Qalamun drainage pond (Figs. 9 and 11) is one of the most important touristic and environmental attractions in Dakhla Oasis because of its scenic landscapes as well as a number of young graduates carrying out a fishing project from the water of the pond and sell to citizens as fresh fish. This helped to enrich the trade and tourism in the region and hence contributing to the creation of jobs for young people.

5.3 Usage of Drainage Water In 2018, the Ministry of Water Resources and Irrigation agreed to cooperate with New Valley Governorate to implement the experience of wheat cultivation on the drainage water of Mut pond, on the area of one acre. This experience, if successful, will be expanded to take advantage of drainage water accumulated as a result of agricultural drainage.

6 Conclusions Sustainable development and agricultural progress in Dakhla Oasis have been lagging behind expectations. This chapter reviewed previous investigations for evaluating the

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Fig. 11 Qalamun Drainage Pond

hydrogeologic conditions of Dakhla Oasis. The Nubian Sandstone basin is tectonically affected by regional faults and is divided into different sub-basins. The salinity of the aquifer changes vertically and laterally. In general, the salinity decreases with depth in Kharga and Dakhla Depressions, from 1,000 ppm in the upper horizons to 200 ppm in the lower ones. In addition, a review of the irrigation system and drainage ponds are highlighted. Detailed survey and test drillings together with the intensive

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oil exploration wells in the northern part of the Western Desert made it possible to assess the regional hydrogeologic setting of Dakhla Basin. Flooding irrigation is one of the main reasons for water consumption in agricultural operations. Drainage networks are one of the main factors that influence the distribution of ponds in the depression.

7 Recommendations It is recommended to put agricultural drainage ponds in the depression under environmental supervision, through the preparation of a monitoring system to get the most benefits from those ponds economically, as well as the protection of agricultural soil nearby from deterioration due to the processes of salinity increasing of soil and water. For Mut pond, it is recommended to take some actions until completion of some proposed studies: a. Rationalize water consumption in agriculture which reduces the amount of wastewater b. Conduct a survey study to select a low area (depression) where wastewater from the ponds is collected in a pond or a large pond for fish farming. There is natural depression South-West Rashda at a level of less than 125 meters, while the areas at Mut are at a level of about 150 meters c. Water with low salinity to be processed and recharged in the groundwater aquifer (Artificial recharge) or used in the cultivation of wooden trees. As for the rest of the lakes in the oasis, there are a number of proposed studies and experience required including: Conducting a series of detailed studies related to this problem that includes: – Assessment of the hydrological and hydrogeological conditions of the groundwater aquifer (number of wells—discharges—groundwater level—productivity—groundwater chemistry—etc.) – Determination of soil quality and characteristics and identification of crop types with economic productivity. – Study of the agricultural drainage network (quantity of daily discharges—wastewater chemistry…) – Conduct a topographic survey to determine the areas of natural depressions that can be used for drainage ponds to be at a level lower than that of agricultural lands and drains – Invest the surplus water of these ponds in fish farms to provide protein at an appropriate cost – Geological, hydrogeological and geophysical investigations to select the most appropriate locations to recharge the groundwater aquifer with the excess water

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– – – – –

S. F. Elbeih and E. A. Zaghloul

and to compensate the groundwater reservoir in the areas of wells that are mechanically discharged A study to change the irrigation systems from irrigation by flooding to sprinkling or drip irrigation to reduce water losses and reduce the amount of wastewater received in the drains Construction of sewage treatment plants for the villages Producing a land-use map to show the locations of the population accumulation Using remote sensing techniques and geographic information systems (GIS) in the construction of a digital information system Best usage of the pond water by clearing it out of grass and using it as a fish farm Using modern techniques (remote sensing, numerical modeling, etc.) in providing old and new data and information about the areas of study studied by researchers.

References Abu Zeid H (2015) Environmental Assessment of the agricultural drainage pools in El Dakhla depression, Western desert of Egypt. “A study in physical geography.” Using remote sensing techniques and geographic information systems Ass Univ Bull Environ Res 8(2) October (in Arabic) ASRT (2016) Production of an Atlas for Hydrogeological Maps of the Southwestern Desert Egypt. Funded project from Academy of Scientific Research and Technology (ASRT), Egypt (2015– 2016) Continental Oil Company (CONOCO) (1987) Stratigraphic map of Egypt 1: 500,000. In Maurice Hermina E, Franz K List (Eds) Ebraheem AM, Riad S, Wycisk P, Sefelnasr AM (2004) A local-scale groundwater flow model for groundwater resources management in Dakhla Oasis, SW Egypt. Hydroge J December 12(6):714– 722 El-Zeiny AM, Elbeih SF (2019) GIS-based evaluation of groundwater quality and suitability in Dakhla Oases, Egypt. Earth Systems and Environment. Published online 22 Aug 2019 Ezzat MA (1974) Groundwater series in the Arab Republic of Egypt, exploitation of groundwater in the El Wadi E1 Gedid project area, parts I–IV. General Desert Development Authority, Ministry of Irrigation, Cairo Haynes VC, Mehringer PJ, Johnson DL, Hass H, Muller AB, Zaghloul E, Sweedan A, Wyerman TA (1987) Evidence for the First Nucclear—age Recharge of Shallow Groundwater Arbain Desert, Egypt. Natl Geogr Res Sci J 3(4):431–438 Heinl M, Thorweihe M (1993) Groundwater resources and management in SW Egypt. Catena Suppl 26:99–121 Hesse KH, Hissene A, Kheir O, Schnaecker E, Schneider M, Thorweihe U (1987) Hydrogeological investigations of the Nubian Aquifer System, Eastern Sahara. Berliner Geowiss. Abh (A) 75:397– 464 Hussein HM, Ghoubachi SY (2017) Geophysical and hydrogeological investigation to study groundwater occurrences in the Taref Formation, south Mut area—Dakhla Oasis—Egypt. May 2017 J Afr Earth Sci 129:610–622 Hewaidy AA, Farouk S, Bazeen YS (2017) Sequence stratigraphy of the Maastrichtian-Paleocene succession at the Dakhla Oasis, Western Desert, Egypt. J African Sci 136:22–43 Kato H, Iwasaki E (2016) Rashda: the birth and growth of an Egyptian Oasis Village. Brill, Leiden and Boston

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Mansour HH, Issawi B, Askalany MM (1982) Contribution to the geology of West Dakhla Oasis area, Western Desert. Egypt Ann Geol Surv Egypt 12:255–281 NASA (2005) Shuttle Radar Topography Mission data sets. National Aeronautics and Space Administration. http://www.jpl.nasa.gov/srtm Patterson LJ, Sturchio NC, Kennedy BM, van Soest MC, Sultan M, Lu Z-T, Lehmann B, Purtschert R, El Alfy Z, El Kaliouby B, Dawood Y, Abdallah A (2005) Cosmogenic, radiogenic, and stable isotopic constraints on groundwater residence time in the Nubian Aquifer. W Desert of Egypt Geochem Geophys Geosyst 6:Q01005. https://doi.org/10.1029/2004GC000779 Salem O, Pallas P (2001) The Nubian Sandstone Aquifer System (NSAS). In: Puri S (ed) International shared (transboundary) aquifer resources management—their significance and sustainable management. IHP-VI, IHP Non Serial Publications in Hydrology. UNESCO, Paris Thorweihe U (1990) The Nubian Aquifer System. In: Said R (ed) The Geology of Egypt: Lisse. Balkema, The Netherlands, pp 601–614 USGS (2004) SRTM data, USGS Seamless Data Distribution System-Enhanced. United States Geological Survey. http://srtm.usgs.gov

History of Wells in Rashda Village, Dakhla Oasis Erina Iwasaki

Abstract The livelihood in an oasis depends on groundwater drawn from wells. Hence, the oasis has a well-centred society determined by the nature of the well. In the study village in Dakhla oasis, wells are classified into five types: government wells (bir hukumi), local wells (bir ahli), investment wells (bir istithmari), surface springs (‘ain sathi), and Roman springs (‘ain rumani). Their names imply a distinction between springs (‘ain) and wells (bir). Different types of wells have different forms of livelihoods. By focusing on the history of well drilling in the study village, this chapter attempts to understand how the universal issue of the relationship between humans and water changed with technological development. Keywords Well · Drilling · Technology · Groundwater · History

1 Introduction The livelihood in an oasis depends on groundwater drawn from wells. Hence, the oasis has a well-centred society determined by the nature of the well. In other words, the nature of the well determines the pattern of landholding, cultivation, and social relations between the villagers. This chapter examines the development of well drilling in Rashda village in Dakhla Oasis. Rashda village is one of the villages in Dakhla Oasis and depends on the Nubian Aquifer for their water resource, as do the other villages. In Rashda, wells are classified into five types: government wells (bir hukumi), local wells (bir ahli), investment wells (bir istithmari), surface springs (‘ain sathi), and Roman springs (‘ain rumani). Their names imply a distinction between springs (‘ain) and wells (bir). The villagers recognize water sources according to depth: i.e., they are called wells (bir) if the source must be tapped using a drill or ‘ain if the water bubbles up naturally and only needs to be cleared from time to time. However, with the disappearance of artesian wells, “‘ain” is now becoming a historical name. E. Iwasaki (B) Faculty of Foreign Studies, Sophia University, Tokyo, Japan e-mail: [email protected] © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_12

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Although water use differs by region according to the history, politics, and economy, the main water problems are the same around the world. The abovementioned irrigation districts that depend on different types of wells have different forms of livelihoods. By focusing on the wells drilled in Rashda village, this chapter attempts to understand how the universal issue of the relationship between humans and water changed with technological development.

2 Development of Modern Wells in Dakhla Oasis 2.1 Wells and Boring Until the Beginning of the Twentieth Century Little is known regarding the ancient methods of extracting water. Many of the wells in Dakhla Oasis date back to the Roman era, but many ancient wells are completely filled with sands, and no information could be found to understand the ancient method of drilling. However, geologist H. J. Llewellyn Beadnell, who travelled to Dakhla Oasis and spent nine years from 1896 to 1905 in the Libyan Desert (Western Desert), observed that the ancient method of drilling used in the Roman era was as follows1 : The bores are practically in all cases lined to a depth with wooden casing, manufactured from the wood of the doum-palm, date-palm, or acacia, which doubtless were then, as now, cultivated in large numbers in the oasis. The timber was carefully fashioned into the required lengths and fitted together by water-tight joints. During the cleaning operations to which many of the old wells have been subjected in modem times, portions of the ancient casing have frequently been extracted, and some of the examples which I have examined, especially those made of acacia, proved to be in an excellent state of preservation. The wood of this particular tree—‘sunt,’ as it is locally called—has remarkably enduring qualities both in and out of the water, though not when subjected to alternations of wet and dry. Still, that it should in some cases have retained its original qualities since Roman times is noteworthy. (Beadnell 1909: 186–187)

Beadnell observed in those days that the well-sinking method consisted of a combination of the ancient boring method described above and modern boring practices. The local method at the time of Beadnell at the beginning of the twentieth century was similar to the ancient or traditional boring practice. It consisted of sinking a rectangular shaft that was usually 2 m2 . This work is carried out by hand, the ordinary native ‘fass’ being almost the only implement used. As the shaft is cut out, it is timbered with lengths of palm-wood strung one below the other, to prevent the walls from falling in. The excavation is carried as deep as possible, the limit generally depending on the amount of sub-surface water met with. In the oasis 1 Beadnell

was sent to the Libyan Desert as a member of the Geological Survey of Egypt from 1896 to 1905. He did nearly nine years of survey and exploration work in the Egyptian deserts. He oversaw extensive boring and land-reclamation in the oases in the Libyan Desert.

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of Dakhla, where the superficial strata consist almost entirely of clays, it can usually be continued to a depth of about 30 metres. (Beadnell 1909: 189) The timbered shaft was placed on the center of wooden casing, to form a vertical pipe from the base of the shaft to the surface of the ground. The pipe was either square or round in section and was usually made of acacia. “The square variety of casing usually has an inside width of 36 centimetres, the thickness of the wood being 4 or 5 centimetres; the circular, and perhaps more common, variety is made with an inside diameter of 35 centimetres”. “The casing, of course, eventually forms the actual channel through which the artesian water flows to the surface. The space intervening between the sides of the timbered shaft and the central pipe is then filled in with a mixture of sand and clay, firmly packed down, to hold the pipe securely in position, and prevent the escape of water should any of the joints become leaky”. (Beadnell 1909: 190)

The modern boring practices consisted of the hand drilling rigs and American steam rigs, both of which use a steel casing that can dig up to 200 to 300 m (see Figs. 1 and 2). These practices were probably introduced in Dakhla Oasis at the end of the nineteenth century. The modern methods were first introduced by Hassan Effendi, a servant of a French engineer Lefevre who was sent to Dakhla Oasis by the Egyptian government to instruct the inhabitants on the use of modern drilling methods (Beadnell 1909). According to Beadnell, using the hand drilling rig was the method used with the hand machines and is the same as the traditional method in principle, “with the exception that the preliminary excavation is dispensed with, the bore being drilled from the surface and lined with metal casing down to the Water-bearing Sandstones. The casing is driven using a heavy weight, or ‘monkey,’ attached to the boring-rod” (Beadnell 1909: 196–197). On the other hand, the steam rigs are of American manufacture and the design usually employed in the United States’ oil-fields. In this method, a heavy weight is suspended from a cable and worked by steam power to give a rapid succession of blows to cut out a circular hole through the hardest of rocks (Beadnell 1909: 196– 197). However, these boring methods were expensive, and it was difficult to maintain and repair the wells. In particular, the steam rigs necessitated skilled drillers with the difficulty of repair, and the initial cost was high. As Beadnell observed, the modern technology of rotary drilling was introduced in the mid-nineteenth century, and the number of wells drilled with modern technology was already starting to increase at the beginning of the twentieth century. The improvement of the boring method led to the construction of many new wells. Beadnell lamented that the local villagers quickly learned the new method and promiscuously sunk “a great number of new bores, without regard to the probable effects on the older wells irrigating the existing palm-groves and cultivated lands, with the result that, more especially in the oasis of Dakhla, a great deal of harm was done. Whole districts suffered a general lowering of the water level, with many of the wells ceasing to flow altogether. This was the direct outcome of the excessive number of new bores put down in certain districts where the inhabitants were sufficiently rich and influential to get and retain possession of the majority of the newly-imported boring-rigs” (Beadnell 1909: 188).

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Fig. 1 A steam rig. Source Beadnell (1909: 197)

2.2 Deep-Well Boring Since the Mid-Twentieth Century The number of deep wells has increased drastically since the mid-twentieth century. Introduction of the deep-depth drilling machine enabled the drilling of wells up to one thousand metres, and the development of a groundwater probe made it easier to search for groundwater. Moreover, the power pumps diffused the water supply more than the method of drawing water using the animal power of camels and cows. Thus, the development of technology after the mid-twentieth century enabled the discharging of a large amount of water that could not have been imagined previously. However, the development of well-drilling technology has transitioned the well-drilling actors from the local communities and farmers to the state and large

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Fig. 2 A hand drilling rig. Source Beadnell (1909: 197)

enterprises. This transition has occurred because drilling a deep well and discharging water from it requires a large amount of money; therefore, the actors are limited to those who have a large capital. In Egypt, the governmental project of New Valley Project was begun in 1958 in the Western Desert. This project was a large land reclamation project that includes irrigation and rural infrastructure constructions and was conducted until the 1970s. In the 1980s, the East Oweinat Rural Development Plan, which was another large-scale project, started in the southern part of the Western Desert. This project was funded by the government and now implemented by private companies. The problems of the rapid development of deep wells were already indicated in the 1970s: e.g., the decrease in the artesian water pressure increased the need for lifting water by mechanical devices. Modern pumping was not yet started in Dakhla Oasis, but it was relatively common in the north and south areas of Kharga Oasis and used the diesel-operated, shaft-driven pumps obtained from the United States, India, and Denmark (Clarke 1979: 52). Thus, pumping costs have increased as the water level has decreased.2 Recently, the government has begun installing solar energy pumps in the Western Desert to solve the problem of needing pumping fuel.

2 Also,

the problems of corrosion using iron pipes were pointed out by the experts (Clarke 1979).

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3 Wells in Rashda Until the Beginning of the Twentieth Century In arid areas, the history of a village is closely linked with water. In the case of Rashda, one of the villages in Dakhla Oasis, its village history started in the latter half of the nineteenth century when some people of Qalamun village, which was one of the powerful villages in Dakhla Oasis, migrated to Rashda (Kato and Iwasaki 2016: Chapter 5). Before the formation of Rashda village, there were several wells in the direct area of Rashda village, and the agricultural lands were irrigated by Qalamun villagers using the water extracted from these wells. It is said that the people moved from Qalamun village to the hilltop area, which is the actual old residential area of Rashda village, to live closer to their land and wells. The villagers’ lives that depended upon the groundwater would not have been a stable one. The wells at that time were shallow artesian wells dug in the traditional manner. The wells had depths less than 120 m and were supposed to last for 30 to 40 years. However, the wells often dried up due to the lower water table, changes in the water streams and groundwater table, and degradation of the well such as the collapse of the well wall. Afterwards, the villagers dug another well to replace the well that had dried up. A document dated 1937 in the name of the ‘umda (village chief) shows that the water flows were a major concern of the villages at the beginning of the twentieth century (Kato and Iwasaki 2016: 124–126). This document compared the water withdrawal amount of the wells in Rashda village in 1883, 1907, and 1937. This document was probably elaborated by the ‘umda to issue licenses for drilling a new well. According to this document, there were 16 wells in 1883 with a total water discharge of 146 qirat per day.3 In 1907, however, the water discharge amount decreased to 85 qirat, and in 1937, the water discharge amount decreased to 62 qirat and five wells dried up. There were 13 ‘ain that existed in 1883 in Rashda: Ain al-Rahma, Ain al-Shishlana, Ain al-Musid, Ain al-Jumaiza, Ain al-Balad, Ain al-Duma, Ain Sahsah, Ain al-Rashda, Ain Shandum, Bir al-Majnun, Bir Hamam wa Mahmud, Bir Qara Birqas, and Bir al-Qadim. In 1937, five (Ain al-Balad, Ain al-Duma, Ain Sahsah, Ain al-Rashda, and Ain Shandum) of the springs already had no water flow (Kato and Iwasaki 2016: 124–126). Interestingly, this document discusses that the demography, i.e., the population, in contrast to the decreased water discharge, increased from 900 in 1883 to 1500 in 1907. This document reveals that the ‘umda perceived the water discharge level to be insufficient relative to the population size in the village. The document also shows that the solution of water deficiency was perceived to be the digging of a new well when a well dried up to supply water for survival. Beadnell described the water and population of Dakhla Oasis at the beginning of the nineteenth century, and his observation also applies to Rashda village: 3A

qirat is the local unit of water quantity. One qirat in the present time is 100 m3 . According to the villagers, one qirat in the beginning of the twentieth century was 200 m3 .

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The patience and industry of the inhabitants of the oases are well exemplified by their unceasing attempts to maintain undiminished the water supply on which their very existence depends. The population must always have borne a direct ratio to the total discharge of the wells, as on the latter depends on the amount of food-supplies which can be raised. At no period, as far as we can judge, has the output of the wells been greater than the requirements, and it is probable that there has always been a population somewhat in excess of that which could be supported by local products, the surplus portion being disposed of by emigration to the Nile Valley. (Beadnell 1909: 198)

The considerable interest of villagers to drilling and maintaining a well is evidenced in the family group najjarin (meaning carpenters) who were local professional well borers.4 The najjarin drilled the well, and the villagers shared the capital and labour. The water share was decided according to the capital, labour, and technology each contributed. The largest share was held by the ‘umda who owned 80% of the cultivated land in Rashda. However, agricultural management was done in collaboration with other farmers. Although the ‘umda owned much of the land in the village and had political power, he had to share with other farmers who contributed the labour. As such, the digging and maintenance of the wells, and the water abstraction and production were done in co-operation and shared between the villagers (see the detailed discussion by Kato in Kato and Iwasaki 2016: Chapter 7). Thus, although many differences would have existed between the ‘umda and ordinary farmers, even small farmers would have the right to access the water.

4 Wells in Rashda Since the Mid-Twentieth Century 4.1 End of the 1950s to the 1970s: Government Wells The turning point of the relationship between humans and water came at the end of the 1950s. The turning point produced the shift from the relationship of human relying on water to that of human relying on technology. The aforementioned New Valley Project started in the Western Desert in 1958 that led to the diffusion of modern rigs with the construction and reclamation of the New Valley in that same year. This project aimed at reclaiming 12,600 m2 of desert land by drilling the wells and intended to move 4 million persons from the old valley of the Nile River. Many new villages were created to accommodate the youth who graduated from universities (graduates). At the same time, this project was a part of the land reform under the socialist reform after the 1952 Revolution and aimed at integrated rural development under the land reclamation scheme in the Gamal Abdel 4 Beadnell

observed the following: “The methods of dealing with wells in which the flows have diminished or altogether ceased are of considerable interest, as they have given rise to a class of men called ‘ghattasin’ (divers), which one would never have expected to find in such remote and arid localities as the oases of the Libyan Desert” (Beadnell 1909: 193).

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Nasser era. Therefore, not only new villages but also old villages were covered by the project. The wells drilled for these projects are called governmental wells and are under the strict control of the government. In fact, the General Authority of Desert Development managed the land reclamation projects, including the drilling of government wells. This authority later became the Ministry of Agrarian Reform and Land Reclamation in the 1960s, which separated into two ministries: i.e., the Ministry of Agriculture and the Ministry of Land Reclamation.5 In Rashda, the desert land dispersed between the irrigated lands were reclaimed, and the wells were drilled by the General Authority of Desert Development. The wells are currently owned and managed by the Irrigation Authority under the Ministry of Water Resources and Irrigation. Since the government wells are drilled as part of the New Valley land reclamation project scheme, the reclaimed land is given to beneficiaries, who are usually chosen according to the criteria of being impoverished or landless villagers. Each beneficiary receives 4 or 5 feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) of land leased from the government and an equal right to water. Although the water right is given to the beneficiaries, the Ministry of Water Resources and Irrigation affects the decisions and management. Farmers oversee the management and distribution, but they are under the supervision of the Ministry. There are four such districts irrigated by government wells in Rashda: Well No.1 with 454 feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) and 100 beneficiaries, Well No.2 with 371 feddans and 32 beneficiaries, Well No.3 with 167 feddans and 34 beneficiaries, and Well No.4 with 63 feddans and 150 beneficiaries. Government wells generally have a depth ranging from 800 to 1,200 m and are supposed to last for 50 years. Many of them were drilled at the time of the construction campaign in the New Valley. At the time of drilling, they were artesian wells, but the ‘deep pump’ was installed later. Also, the number of wells increased, especially after 2000, to replace or supplement the older wells that had decreased water discharge. Most of those drilled after 2000 have a depth greater than 700 m. Compared to the initial wells that had a depth of approximately 500 m, the well depth has increased. For instance, Well No.3 Irrigation District was started by drilling a well in 1959, called Well No.3. This Well No.3 was an artesian well with a depth of 500 m and ceased to discharge water completely in 1995.6 From the late 1980s, four wells were drilled to maintain the water discharge level. They were dug deeper compared to the initial Well No.3: Well No.3-5 drilled in 1988 has a depth of 833 m, Well No.3-7 drilled in 1999 had a depth of 530 m, Well No.3-12 drilled in 2004 had a depth of 1046 m, and Well No.3-17 drilled in 2008 had a depth of 739 m (Table 1). Moreover, 5 In

1996, they were reintegrated into one ministry, i.e., the Ministry of Agriculture and Land Reclamation. 6 It was an artesian well and could have continued to discharge water if a pump had been installed. However, instead of installing a pump, the Department of Irrigation subsequently drilled a new well beside the original Well No.3-17.

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Table 1 Governmental wells in Rashda (2016) Flow (m3 /day) in the year of drilling

Method of water withdrawal 2016

499

3593

Deep pump

298

542

Year of drilling

No.A

1963

No.B-1

1964

No.1-6

1962

535–500

4796

Deep pump

No.1-13

2006

974–1000

1709

Deep pump

No.1-16

2008

451

3035

Deep pump

2100

No.2

1962

500

1505

Deep pump

1284

No.2-10

1996

826

1780

Deep pump –

No.2-18

Depth (m)

Flow (m3 /day) 2016

Name of wells

500

Dried up

Diesel

2300

No.3

1959

500

3600

Artesian

No.3-5

1988

833

3413

Deep pump

No.3-7

1999

530

3413

Deep pump

2150

No.3-12

2004

1046

3030

Deep pump

2761

No.3-17

2008

739

603

No.4

1985

543

1026

Diesel

1029

No.4-8

2000

748

2160

Diesel

3200

No.4-10

2002

1790

Diesel

No.4-14

2005

986–1000

2299

Diesel

1709

No.11

2004

1050

3488

Diesel

3496

No.15

2008

827

Dried up 2150

Deep pump 2950–2900

–

925

Diesel

364

No.19

400

Diesel

2000

Ain Shishlan

400

Diesel

–

Source Information collected by an informant in 2016

all wells except for Well No.3-12 were artesian wells originally, but with the decrease in the water level, they were changed to deep-pump wells.

4.2 Since the 1980s: Investment Wells and Surface Springs In the mid-1970s, the government stopped doing large-scale rural socialist development projects. Instead, groundwater drilling and land reclamation projects were operated by private companies and investors under the economic liberalization policy of Sadat. The development under Mubarak since 1990s is also similar. Megaprojects such as the Toshka project and the East Oweinat project were launched by large

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public and private companies, the army, and foreign investors, especially from the Gulf countries. Economic liberalization also affected the well drilling in Rashda village. In 1995, the Ministry of Irrigation authorized to deliver licenses of drilling a well with a depth less than 300 m to the individuals and companies. Since then, many small investors who are mostly relatively wealthy villagers dug shallow wells. These wells are called investment wells or surface springs according to the license and their depth. Investment wells are exploited by one or several individuals (investors) under a scheme of the General Authority for Investment (al-Hay’a al-Amma al-Istithmari) that began in 1995. This organization is an affiliate of the Ministry of Investment. An individual who wants to start an agricultural business may dig a well after obtaining permission from this organization. The first two investment wells were drilled in 1996. These wells were drilled by individuals and have a depth of 500 m. By law, the depths of investment wells must be 300 m, and the area of irrigation of each well is defined as 10 feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m). Actual depths and areas are often larger. Many wells have a depth of 500 m or less and are supposed to last for 20 to 30 years. There are 10 wells of this type in Rashda, covering a total area of approximately 950 feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) as of 2009. Investment wells have an image of being for investors or businessmen, from the outside. However, in the case of Rashda, the investors are mostly small investors who are native villagers in the middle-income category. They are generally co-owned by individuals, and their irrigated land is privately owned after being leased for 10 years from the government. Surface springs (‘ain sathi) are popularly recognized as springs that flow up by themselves, although their depth is generally between 120 and 150 m. They are drilled with permission from the Land Reclamation Fund. They are individually or collectively owned and managed by the farmers. Their irrigated land is leased to cultivators by the government, which owns the land. By law, a surface spring’s irrigated area is defined as 10 feddans (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m). There are about 25 springs of this type as of 2009.

5 Change in the Human-and-Water Relationship 5.1 Years of Well Construction We collected data and information on approximately 70 wells and springs in Rashda village. The information collected on these wells includes the name, type of well, location, depth, year of drilling, mode of effusion, quantity of water flow at the time

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of drilling (cubic metres per day) for government wells, and status of operations (whether they are operational).7 Table 2 shows the types of well classified by construction year. Among these, the oldest type is Roman springs followed by local wells. These two types were the only water sources that existed before 1959. Roman springs are popularly recognized as dating back to the Roman era, although most of them are assumed to be 200 years old or less. They had a depth ranging from 85 to 100 m. They have all dried up now. Local wells (bir ahli) are exploited by local farmers, who dig them in the traditional local way and own and manage them collectively. Most of them were initially dug as artesian wells and had a depth of 85 m or less. However, most of these traditional wells have dried up and been equipped by diesel pumps. There were 29 wells of this type in Rashda, of which 13 were operating in 2009. Besides local wells and Roman springs, all the wells in Rashda were drilled after the New Valley Project began. The following three government wells were drilled in 1959: Well No.1; Well No.2; and Well No.3, and all three wells were drilled by an Italian company that worked on the New Valley Land Reclamation Project. All of these wells had a depth of 500 m. Many wells were drilled after 1996 on the outskirts of Rashda (Fig. 3). During 1970 and 1995, only three new wells were drilled. In contrast, the drilling of new wells increased tremendously during 1995 and 2004, with 14 new wells being drilled between 1995 and 1999, and 26 between 2000 and 2004. This acceleration of drilling was caused by the authorization of drilling in 1995, as was indicated in Sect. 4.2. Surface springs grew remarkably in number between 2000 and 2004, with 17 new wells being drilled during this four-year period. The surface springs were the preferred type well of the villagers, probably because of their low cost. As mentioned above, surface springs are shallow wells with depths of 120 or 150 m. Therefore, they only need a small drilling machine and a small submersible pump, so they do not require a huge amount of money. According to an informant, the cost of drilling was estimated to be around 30,000 Egyptian Pounds in 2008. Investment wells, which have a depth of around 500 or 700 m, require approximately 300,000 Egyptian Pounds, an amount 10 times more than that of surface springs.

5.2 Continuous Well Drilling8 What does the shift from the traditional local wells to the governmental wells and investment wells as well as surface springs imply? The modern technology enabled the assurance of water discharge by digging deeper (government well) or digging a shallow well more easily (investment well, surface spring).

7 See

Kato and Iwasaki (2016: 184–186) and Kato et al. (2010: 17–18) for detail. section is based on Kato and Iwasaki (2016: 186, Chapter 10).

8 This

1

3 4

1

Source Kato and Iwasaki (modified after 2010: 38–39)

11

2005–2008

13

4

2000–2004

Total

3

1996–1999

7

2

1

2

1

1

1970–1995

3 1

4

1950–1959

1960–1969

8

Before 1950

Operating

Government well Stopped

Stopped

Operating

Local well

Table 2 The number of wells constructed in Rashda by well type (2009) Investment well

10

1

3

6

Operating

2

2

20

2

17

1

Operating

Surface spring Stopped

3

Unknown

70

8

26

14

3

1

7

8

Total

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History of Wells in Rashda Village …

Fig. 3 Location of wells and springs in Rashda (2007) (Kato et al. 2010: 16)

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Ain al-Rahma, believed to be the oldest of the Roman Springs, was replaced by Bir Hamam wa Mahmud when it dried up in the 1930s. However, the water flow of the latter well also decreased. An informant recalls that he swam in the Bir Hamam wa Mahmud in the 1980s, but it finally dried up in the 1990s. A new well, Bir alJadid, was also drilled in 1929 to support the water supply but its water flow also decreased. In 1985, Well No.4-20 (or Bir 4 Gharbi, i.e., Well No.4 West) was drilled to a depth of 543 m (Table 3). However, because of its insufficient water supply, a surface spring (‘ain sathi) was dug to a depth of 75 m in 1994, followed by Well No.4-13, which was drilled in 2003. It is a deep well, with a depth of 1,180 m. The water supply from Ain al-Balad also stopped in the same period as Ain alRahma. The well was replaced by Bir Ain al-Balad, drilled in 1927, but this well also dried up in the 1950s. Therefore, the agricultural field originally irrigated by the water from Ain al-Balad received water from the governmental Well No.3, and from 1977, the agricultural field was also supplied by a new local well of Dulab Bahry, which dried up soon after. Currently, the water is supplied by Well No.3 and Haramiya Musid, which was dug in 2004. Another case is Ain al-Shishlana, which is a Roman spring that survived until the 1990s. In the 1980s, the water flow was so abundant that it was used to drive the wheat mill. However, the spring dried up in the 1990s, and it was replaced by Well No.4-20, which also delivers water to the district of Ain al-Rahma. Table 3 Replacement of Roman springs with new wells (2016)

Ain al-Rahma

Ain al-Balad

Ain al-Rahma Roman spring Bir Hamam wa Mahmud

Local well

Bir Jadid

Local well

Well No.20/4 (Well No.4 West)

Local well

Ain Sliman

Surface spring

Well No.13/4 (Well No.4 East)

Local well

Ain al-Balad

Depth (m)

Year of digging

Current status

Around 100

Before 1883

Dried up in 1940s

Before 1900

Dried up before 2005

1929 543

1985

Operating

75

1994

Operating

1180

2003

Operating

Roman spring

Before 1883

Dried up before 1937

Bir Ain al-Balad

Local well

1927

Dried up in 1950s

Dulab Bahry

Local well

1977

Dried up

Haramiya Musid

Local well

2004

Operating

Source Kato and Iwasaki (modified after 2016: 187)

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These new wells became deeper as shown in the actual depth of wells. They are categorized as local wells in the village are called replacement wells that were drilled by the Ministry of Irrigation to replace the dried-up wells. They are supervised by the Ministry of Irrigation. Thus, their discharge level is under the control of the government, in contrast to the surface springs or investment wells.

6 Conclusions Until the first half of the twentieth century, the villagers’ lives depended on the water accessibility that was limited and unstable. In a sense, the life of those days was one determined by the water. The drastic change of the human relationship with groundwater occurred with the development of modern technology since the late 1950s. The vertical and horizontal exploitations of the groundwater were enabled by the deep-well drilling machines and the development of pumping technology. The technology of water discharge enabled the discharge of a large amount of groundwater and the ability to overcome water deficiency, as did the human control of the Nile River. A consequence of the increased drilling since then is the lowering of the groundwater level. An informant and other farmers, recalling their childhood during the beginning of the 1990s, said that the artesian wells had functioned well up to that period. The water even came out so strong that it was difficult to close the valve, but since then, it has become easy to do so. Today, all the artesian wells are dried up, and the water can be discharged only by pumping.

7 Recommendations This chapter examined the history of wells in Rashda village to help explain the relationship between humans and water. The study revealed the increase of wells with the development of technology whose consequence was the lowering of groundwater level. To further study the consequences, research is required to monitor the groundwater table. Another important subject is the villagers’ perception of groundwater. Interestingly, it seems that the villagers, including the informant and other farmers, view the problem as a matter of water flow uncertainty, rather than as a risk of exhausting the overall groundwater storage. If the water flow stops from one well, they drill a new replacement well with new well designer. Thus, the drilling of wells continues and has accelerated in recent years to ensure water supply.

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References Beadnell HJL (1909) An Egyptian Oasis: an account of the Oasis of Kharga in the Libyan Desert, with special reference to its history, physical geography, and water supply. John Murray, London Clarke FE (1979) The Corrosive Well Waters of Egypt’s Western Desert. Geological Survey WaterSupply Paper 1757-O, Prepared in Cooperation with the Arab Republic of Egypt, under the Auspices of the United States Agency for International Development. United States Government Printing Office, Washington, DC Kato H, Iwasaki E, Nagasawa E, Anyoji H, Matsuoka N, Kimura R (2010) Rashda: system of irrigation and cultivation in a village in Dakhla Oasis. Mediterranean World, 20 Kato H, Iwasaki E (2016) Rashda: the birth and growth of an Egyptian Oasis Village. Brill, Leiden and Boston Ministry of Agriculture and Land Reclamation (2015) The evolution of the structure of the Ministry of Agriculture. Ministry of Agriculture and Land Reclamation web site http://www.agr-egypt. gov.eg/En_MinHistory.aspx. Accessed on 27 Mar 2015

Development of Land Use and Groundwater in Rashda Village (Dakhla Oasis), 1960s–2018 Erina Iwasaki, Adel Shalaby, Salwa F. Elbeih, and Hossam S. Khedr

Abstract Causes of agricultural land expansion and its impacts on arid ecosystems are fundamental problems challenging sustainability of societies depending on groundwater. Consequently, a thorough understanding of this phenomenon is necessary to avoid future problems. With the objective of identifying land expansion dynamics and the primary drivers, changes in land use in Rashda village— Dakhla Oasis between 1968 and 2018 were analyzed. Land uses were identified using 1968 Corona images and 1988 and 2003 Landsat images and 2018 Sentinel2 images. Groundwater data were collected from field survey and South Western Desert groundwater central laboratory. Results indicated that the surface occupied by irrigation agriculture has accelerated since 1968, and its area doubled over the past 50 years. During that period, there was a simultaneous increase in total population and constructed wells during implementation of the New Valley Project. Thus, human migration and national development are identified as potential drivers of land expansion. Keywords Land use · Groundwater · Satellite images · Wells · Landsat · Irrigation · Agriculture

E. Iwasaki (B) Faculty of Foreign Studies, Sophia University, Tokyo, Japan e-mail: [email protected] A. Shalaby · H. S. Khedr Environmental Studies and Land Use Division, National Authority of Remote Sensing and Space Sciences (NARSS), Cairo, Egypt S. F. Elbeih Engineering Applications and Water Division, National Authority of Remote Sensing and Space Sciences (NARSS), Cairo, Egypt e-mail: [email protected]; [email protected] © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_13

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1 Introduction In arid regions, which depend upon groundwater, land use is closely related to the availability of groundwater, and accessibility to the wells. In this regard, the New Valley Project and development of wells under economic liberalization have a huge impact, as is discussed in Chapter 12 on History of Wells. Causes of agricultural land expansion and its impacts on arid ecosystems are fundamental problems challenging the sustainability of societies depending on groundwater. The relative abundance of water enabled the rapid increase in population in the latter half of the twentieth century (Kato et al. 2014). The land use change analysis showed that the extension of cultivated land was already completed by the 1980s in the North and South subdistricts, after which it spread toward the West (Kato et al. 2012). Consequently, a thorough understanding of this phenomenon is necessary to avoid future problems. With the objective of identifying land expansion dynamics and their primary drivers, this chapter analyzes changes in land use in Rashda village in Dakhla Oasis between 1968 and 2018, and identifies the land uses from which expansion occurred using Corona 1968 image and Landsat images from 1988 and 2003 and Sentinel-2 2018 images. Groundwater wells distributed in the Oasis are related with land-use changes that occurred in that period.

2 Research Site 2.1 Demographic Features Rashda village administratively belongs to Markaz (district) Dakhla, New Valley Governorate in the Western Desert of Egypt. It is located 10 km northwest of Mut town, the administrative center of Dakhla Oasis. Its population in 2017 was 7228 (Table 1). As can be seen from Table 1, the most tremendous population increase occurred between 1947 and 1976, with an annual increase rate of 5.0% in Rashda village. Although the population at the village level is not available for the population censuses 1960 and 1966, the population censuses available at markaz level guided us that this largest population increase occurred between 1966 and 1976 when the New Valley Project has been implemented (Kato et al. 2014: 6). The population tripled from 1947, reaching 4398 in 1976. This phenomenon is similar to that observed in other villages such as Mut town, Qasr, Teneida and other villages in Dakhla Oasis. It is known that during the New Valley Project, many people from outside moved to the New Valley Governorate. This was particularly the case in Kharga and Farafra Oases, where many new settlements were established such as “Baghdad”. For Dakhla Oasis, the migration from outside was smaller in size compared to Kharga and Farafra Oases, and were limited to Mut town or the areas in Qasr. For Rashda village, the population increase during the 1960s would have

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Table 1 Population of Dakhla Oasis and Rashda Village 1937–2017a 1937

1947

1960

1966

1976

1986

1996

2006

2017

Dakhla Oasis

19,476 21,382 21,586 20,511 45,141 57,881 62,350 79,812 101,854

% annual increase

0.9

0.1

Number of 12 shiyakha

13

Rashda

1543

1739

% annual increase

1.2

3.4

−0.8

a

8.2

2.5

0.7

2.5

2.2

13

14

16

34

68

3306

4398

5574

4364

5423

7228

2.9

2.4

−2.4

2.2

2.6

a (1)

Until 1960, Markaz Dakhla belonged to South Sahara Governorate (2) 1960 population census for South Sahara Governorate contained only the population information by Markaz, and not by village (3) Annual increase rate of Rashda for a is between 1947 and 1966 (4) In 1996, Awina village separated from Rashda village (5) In 2017, Balat village and other surrounding villages separated from Markaz Dakhla to become Markaz Balat Source Various population censuses

probably been the result of natural increase and of migration of people moving from other nearby villages. During the period between 1947 and 1976, the residential area expanded also. Rashda village is a village which started in the mid nineteenth century as a settlement belonging to Qalamun village located in the southern direction of Rashda. The villagers lived in the hilltop area, but from the mid twentieth century, most of the villagers moved to the area that was originally a cultivated area. This area formed the actual residential area today (Fig. 1). The actual residential area developed in the 1960s and 1970s. New Valley Project was not just a project of land reclamation, but also a project of social development. Under the socialist regime of President Gamal Abdel Nasser, schools, health unit, agricultural co-operative, youth center were created in the residential area during the 1960s and 1970s. Along with these developments in social infrastructures, many houses were constructed during the same period.

2.2 Topographic Features Figure 2 shows the Digital Elevation Model (DEM) of Dakhla Oasis. Rashda village is located in an area with elevations ranging from 209 to 568 meters above mean sea level (masl). Most of the village lies in low level area, with the elevation ranges from 209 to 312 masl. The elevation of the northern part is rather high, with more than 312 masl.

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Fig. 1 Old and new residential areas in Rashda village. Source Kato and Iwasaki (2008: 25)

Fig. 2 Digital Elevation Model (DEM) of Dakhla Oasis with the red line indicates the boundary of Rashda village. Source SRTM 2000 satellite image

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3 Methods and Data Used 3.1 Data (1) Satellite data The satellite data used were two Landsat Thematic Mapper (TM) images acquired in August 1988 and August 2003, one Sentinel 2 image acquired in August 2018, as shown in Table 2. In addition, Corona images acquired in 1968 are used. Table 2 Technical specifications of the used optical sensors Satellite

Sensor

Bands

Wavelength (µm)

Landsat

Thematic Mapper (TM)

Band 1—Blue

0.45–0.52

30

Band 2—Green

0.52–0.60

30

Band 3—Red

0.63–0.69

30

Sentinel-2

Corona

Spatial resolution (m)

Band 4—NIR

0.76–0.90

30

Band 5—SWIR 1

1.55–1.75

30

Band 6—Thermal Infrared (TIRS) 1

10.40–12.50

August 1988 and 2003

120

Band 7—SWIR 2

2.08–2.35

Band 1—Coastal aerosol

0.443

60

Band 2—Blue

0.490

10

Band 3—Green

0.560

10

Band 4—Red

0.665

10

Band 5—Vegetation Red Edge

0.705

20

Band 6—Vegetation Red Edge

0.740

20

Band 7—Vegetation Red Edge

0.783

20

Band 8—NIR

0.842

10

Band 8A—Vegetation Red Edge

0.865

20

Band 9—Water vapor 0.945

60

Band 10—SWIR—Cirrus

1.375

60

Band 11—SWIR

1.610

20

Panchromatic

Acquisition date

30 August 2018

1.2

1968

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Corona image of 1968 has a low spectral resolution (single band) and because of that, many scholars hesitate to use it. In fact, some scholars have pointed out the limitations of using Corona image due to its course spectral resolution (Single band). Because they are panchromatic images (single layer images), they create difficulties in usage during the auto classification process (Saleem et al. 2018). However, it is the only source of satellite images in the 1960s and is a precious source to understand the land use at the time when New Valley Project had just begun. For this reason, the authors attempted to use source of images, keeping in mind the difficulty and error risk of image processing. (2) Site investigation data A total number of 217 ground truth points for different land use and land cover classes were collected during fieldwork in April 2013 and April 2016. These check points are distributed among all villages of Dakhla Oasis including Rashda village. The assigned land use classes are urban, bare land, water bodies, land under reclamation, and sabkhas (salt flats). (3) Well data1 Information of well location, year of drilling, and type of wells were collected in 2007. The information of well location is used to map their locations on the map using GIS. Data and information were collected from about 70 wells and springs in Rashda village by fieldwork. Also, through field checks in 2014 and 2016, a total of 25 government and local wells were investigated. There are five types of wells; government well, local well, investment well, surface spring, and the Roman spring. (1) Government wells are generally deep wells and drilled by Ministry of Irrigation. There were 12 wells of this type in Rashda. (2) Local wells are usually less than or equal to 85 m deep. This type of well is planned to last for 20 years. There were 29 wells of this type in Rashda. (3) Investment wells have a maximum depth of 500 m and they are intended to last for 20–30 years. There were nine wells of this type in Rashda. (4) Surface spring is as the name implies, has a depth less than 120 m. There were about 34 surface springs of this type. The first one was constructed in 1998. (5) Roman springs. They have a depth ranging from 85 to 100 m and they are exploited by local farmers. There are eight springs of this type, but all of them have now dried up. Among these five types of wells, investment wells and surface springs have increased since the end of 1990s.

3.2 Methods Methods of analyzing the land use using satellite images followed 5 steps: (1) image pre-processing and layer stacking, (2) image sub-setting, (3) image post processing, 1 See

Chapter 12 on history of wells for more details.

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(4) supervised classification, (5) land use/cover change detection. These are common steps used in processing and analyzing the land use. (1) Image pre-processing and layer stacking Layer stacking is the process of combining separated bands to form a single multispectral image file for further analysis. In this study, it was applied using ENVI 5.1 software. This process was followed by defining the wavelength for all bands according to the electromagnetic spectrum of each Landsat sensor. (2) Image sub-setting After the investigation of the images, it was found that the data set covers not only the study area but also a large part of the Western Desert. Therefore, ENVI 5.1 software was used to subset the images by the vector of Rashda boundary to include only the study area. This process decreases the amount of digital data in order to speed up processing which is important when dealing with multiband data. (3) Image post processing Digital image post processing aims to obtain more information from satellite images, which is difficult to get from the raw data. (4) Supervised classification Supervised classification was applied using ENVI 5.1 software. Supervised classification was used to generate land use and land cover classes using Support Vector Machine (SVM) classifier. Comparative analysis clearly revealed that substantially higher overall classification accuracy (95%) was observed with the object-based SVM, compared with that of traditional pixel-based classification (89%) (Devadas et al. 2012). (5) Land use/cover change detection Land use of Rashda was classified to five classes, that are (1) built-up area, (2) agricultural area (including fallow agricultural land detected by visual interpretation), (3) barren land, (4) sand dunes, and (5) water bodies (drainage ponds/lakes). Due to the low level resolution, the classification of land use/cover using 1968 Corona image was difficult. For the areas that were difficult to distinguish either they were barren land or agricultural area, they were assigned as agricultural area. Therefore, it should be kept in mind that 1968 land use/cover detection tends to overestimate the agricultural area. The post-classification change detection analysis describes and quantifies differences between images of the same scene at different times. The classified images were used to calculate the area of different land use/cover and to observe the changes between different years which in this case are 1968, 1988, 2003 and 2018. This analysis is very much useful to identify various changes occurring in different classes of land use as shown by Hegazy and Kaloop (2015). Post-classification comparison change detection was done after classifying the rectified images separately. The classified images were exported to the ArcGIS 10.4 software for vectorization, calculation and comparison of the areas among the different dates.

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Fig. 3 Percentage of land use classes in 1968. Source See Table 2

0%

31%

Built-up land Agricultural land Sand dunes Desert Water bodies

65% 4%

4 Results and Discussion 4.1 Land Use/Cover Classifications Land use/land cover in Rashda was classified into five main classes which are represented in built-up land, agricultural land, sand dunes, desert and water bodies. Rashda village lies in the desert area, so the main class of land use is desert. Area (hectare) of each land use class is calculated for the years 1968, 1988, 2003 and 2018.

4.2 Land Use/Land Cover in 1968 In 1968, the main land use class, the desert, is calculated to be 2,592.2 ha, and occupied 64.9% of the total land area of Rashda. The second largest class is agricultural land estimated to be 1,219.6 ha occupying 30.5% of the village surface. The third class is sand dunes covering 15.6 ha with 4.1% of the total area. The area of built-up land and water bodies were 3.2 and 15.6 ha respectively as shown in Figs. 3, 4 and Table 3.

4.3 Land Use/Land Cover in 1988 In 1988, the area of desert was 2,088.9 ha occupying 52.3% of the total surface area of the village. Agricultural lands was the second largest, and occupied 1,381.9 ha which represented 34.6% of total village surface. Built-up land where the villagers lived occupied only 48 ha (1.2%). Sand dunes was in the third largest class covering 432.5 ha and 10.8% of the total surface of the village as shown in Figs. 5, 6 and Table 3.

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Fig. 4 Land use classes in 1968

4.4 Land Use/Land Cover in 2003 Table 3, Figs. 7 and 8 show the land use classes area and percentage in 2003 respectively. It was found that, in 2003, the agricultural land came to be the largest class, surpassing the desert which decreased to 40.5% of the total surface. The agricultural land occupied 1,981.8 ha and 49.7% of the total surface. Built-up land was the smallest class with area of 67.6 ha. The area of sand dunes was 202.8 ha. Interestingly, the water bodies which occupied only 1% in 1988 grew to be 3% in 2003.

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Table 3 Area of land use classes in 1968–2018 1968 Land use

Area (ha)

1988

2003

2018

%

Area (ha)

%

Area (ha)

%

Area (ha)

%

Built-up land 3.2

0.1

48

1.2

67.6

1.7

116.6

2.9

Agricultural land

1219.6

30.5

1381.9

34.6

1981.8

49.7

2481.6

62.2

Sand dunes

163.2

4.1

432.5

10.8

202.8

5.1

133.9

3.4

Desert

2592.2

64.9

2088.9

52.3

1617.9

40.5

1064.7

26.7

Water bodies

15.6

0.4

39.9

1

121.2

3

194.4

4.9

Source See Table 2

Fig. 5 Percentage of land use classes in 1988. Source See Table 2

1%

1%

Built-up land

35

Agricultural land Sand dunes

52%

Desert Water bodies

4.5 Land Use/Land Cover in 2018 Agricultural land was the main land use class in 2018, and covered 2,481.6 ha with 62.2% of total surface area. Built-up land area was 116.6 ha occupying about 3% of the total surface area of Rashda. Water bodies was in the third place with area of 194.4 ha and 4.9% of the total area, as shown in Table 3, Figs. 9 and 10. As a result of increase in these classes, the desert area came to be 1,064.7 ha, and its proportion decreased to 26.7% of the total area.

4.6 Land Use/Land Cover Change Detection Changes of land use/land cover classes were detected during the last fifty years from 1968 to 2018 divided into in three periods of 1968–1988, 1988–2003, and 2003–2018.

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Fig. 6 Land use classes in 1988

4.7 Land Use Change Detection from 1968 to 1988 During this period, a high increase was recorded in the built-up area and water bodies. In fact, the built-up land increased in average 2.2 ha per year as shown in Table 4. Meanwhile, the agricultural land increased slightly, annual rate of increase being only 8.1 ha/year. However, it should be noted that this slow increase rate could be due to the overestimation of agricultural land in 1968 as explained in Sect. 3.2.

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Fig. 7 Percentage of land use classes in 2003. Source See Table 2

3%

2%

Built-up land Agricultural land Sand dunes

40%

50%

Desert Water bodies

5%

As a result of the expansion of the built-up and agricultural lands, the desert area decreased in average −25.2 ha per year. Although the increased ratio of the built-up land was higher than that of agricultural land (1,386.4 and 3% respectively), the annual increase rate of agricultural land was higher than that of built-up land (8.1 and 2.2 ha/year respectively).

4.8 Land Use Change Detection from 1988 to 2003 Built-up land increased in average 1.3 ha per year during 1988–2003. This ratio is lower than during 1968–1988. On the other hand, the agricultural land increased 40.0 ha per year. This ratio is higher than during 1968–1988. As the built-up and agricultural lands increased, the desert decreased in average 31.4 ha per year (by 471 ha). In addition, sand dune decreased in average 15.3 ha during this year. This loss of desert land and sand dune on one hand and the expansion of agricultural land on the other hand took place in higher pace than during 2003– 2018. Therefore, it can be pointed out that the land use change mainly of the expansion of agricultural land at the expense of desert land and sand dune took place in the highest pace during 1988–2003. In this period, the conversion of agricultural land at the expense of the desert was estimated to be 502.2 ha of desert land. This conversion of agricultural land occurred in the southern part of the study area as shown in Fig. 11. The built-up area also expanded at the expense of the desert by 8.9 ha. Some bad indicators were found during this period, such as conversion of some agricultural lands to either built-up areas or sand dunes with 7.6 and 0.5 ha. respectively. Interestingly, the water bodies (drainage pond/lakes) increased 5.4 ha every year during this period. It can be pointed out that the conversion of desert land to agricultural land is accompanied by the expansion of water bodies.

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Fig. 8 Land use classes in 2003

4.9 Land Use Change Detection from 2003 to 2018 Built-up land area increased in average 3.3 ha per year during 2003–2018. The agricultural land, on the other hand, increased slower than during the previous period, in average 33.3 ha every year. During this period, it was found that the expansion of the agricultural land at the expense of the desert land (591.8 ha) was more pronounced than in the previous period (502.2 ha). Also, the conversion of desert land to built-up area was estimated

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Fig. 9 Percentage of land use classes in 2018. Source See Table 2

5%

3%

Built-up land Agricultural land

27%

Sand dunes

62%

Desert Water bodies

3%

to be 14.8 ha during this period, compared to 8.9 ha during the previous period. Therefore, it can be pointed out that the conversion to agricultural and built-up lands was mainly from the desert land, and took place in much larger area during this period. It is noticed that the expansion of agricultural land occurred in all over the study area as shown in Fig. 12. The southern part in low land near the water bodies, and north-western part toward the mountain area that was desert land were all affected by the expansion of agricultural land. Some bad indicators appear to be important, conversion of the agricultural lands to either built-up areas or sand dunes (34.3 and 3.4 ha.).

4.10 Land Use Change and Development of Wells in the Northern Section of Rashda Village Development of wells and their associated cultivated lands has taken place in the outskirts of the village (the northern section of the village). The local wells were mainly constructed near residential areas whereas newer wells were constructed in the outskirts (Fig. 13a, b). To analyze the development of wells in relation to the landuse change, this section uses information of the wells mentioned in Sect. 3.1, and the results of landuse detection obtained in Sect. 4.1. By matching the two types of information using GIS, the development of agricultural land will be studied in relation to the well development, which is the primary driving force of agricultural land development in the oasis depending upon groundwater. In the year 1968, the wells that existed were Roman springs, local wells, and government wells. Local wells were drilled in the old cultivated lands that were previously irrigated by the Roman springs which have already dried up before the 1950s. These local wells are bir al-Balad, bir Ain al-Balad, bir al-Qibli Maarif drilled in the 1920s, and bir Hamam drilled in 1943. Three government wells (Well No. 1, No. 2, and No. 3) were also drilled in the early 1960s within the framework of New

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Fig. 10 Land use classes in 2018

Valley Project. These government wells were drilled in the area that was mostly desert area. Well No. 1 was drilled in the northern part of the village that was previously a desert land. Well No. 3 was also drilled in the desert land that was located within the cultivated land. In 1988, four additional wells were drilled; an additional government well (Well No. 2 Irrigation area in 1962), and another government well “Itali” drilled for Well No. 3 Irrigation area in 1962, and two local wells called Dallub Bahri in 1977, and

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Table 4 Land use change area (ha) and average annual rate of increase (ha/year) during 1968–2018 1968–1988 Land use class

(ha)

Built-up land

1988–2003 (ha/year)

(ha)

2003–2018 (ha/year)

(ha)

(ha/year)

44.8

2.2

19.6

1.3

49.1

3.3

Agricultural land

162.3

8.1

599.9

40.0

499.8

33.3

Sand dunes

269.3

13.5

−229.7

−15.3

−68.9

−4.6

−503.3

−25.2

−471.0

−31.4

−553.3

−36.9

24.3

1.2

81.3

5.4

73.3

4.9

Desert Water bodies

Well No. 3 Gharbi in 1985. In 1988, an another government well called “Replacement Well No. 3” was drilled to replace the well drilled in 1962. Thus, it can be said that the well development until 1988 was driven by two forces. The first is replacement of old Roman wells by local wells that occurred in the old cultivated area, and government wells drilled in the desert land, some of which were replaced during 1970s and 1980s by new replacement wells. As pointed out in Sect. 4.2, the largest extension of agricultural land occurred between 1988 and 2003. This period also witnessed an acceleration in well drilling, which was surface springs except for 3 local wells and one government well that were drilled as either replacement or supplement wells that discharged less water. Nine surface springs were drilled between 2000 and 2003, in the area that was desert land until 2003. As mentioned in Chapter 12 (On History of Wells), the surface springs are the wells authorized to drill under the economic liberalization since the late 1990s. These wells are drilled by the farmers themselves or by the small investors. Therefore, the period after 1988 can be characterized as the period of drilling acceleration driven under the economic liberalization by the small investors. Figure 14a, b show the distribution of wells in the northern extension of Rashda village by type and year of construction overlying different land use classes (1968–2018). These figures show clearly the expansion of cultivated lands in the past 50 years (from 1968 to 2018) and the distribution of different wells.

5 Conclusions This chapter aimed at clarifying the changes in land use and its relationship with the well development in Rashda village, using satellite images and wells information that collected from intensive fieldwork at Rashda village. The main findings can be summarized as follows. First, although we would have to refrain from drawing a conclusion for the period 1968–1988 due to the difficulty of using Corona satellite image of 1968, as a whole, there was a huge change in land use/cover during the past 50 years (1968–2018). This is mainly brought by the conversion of desert land to agricultural land, and in lesser extent to built-up land.

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Fig. 11 Conversion of land use/cover classes from 1988 to 2003

Second, the expansion of agricultural land was closely associated with drilling of wells: governmental wells until 1980s, and surface springs from the period after 1988. The latter type of well started under the economic liberalization by small and medium investors (farmers and enterprises). Thus, it is pointed out that the expansion of agricultural land in Rashda village during the period observed 1968 till now was mainly driven by the investors under the economic liberalization.

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Fig. 12 Conversions of land use/cover classes from 2003 to 2018

It is associated with complex phenomena, one of which is the increase of water bodies (drainage lakes). More agricultural lands lead to more drainage lakes.

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Fig. 13 a Location of wells by type of well. b Location of wells by year of drilling. Source Data collected in 2007, Kato et al. (2010: 15, 16)

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Fig. 14 a Location of wells by type overlying Land use of different years (1968–2018). b Location of wells by date constructed overlying Land use of different years (1968–2018)

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6 Recommendations As an output of this extensive study, a number of recommendations could be extracted: 1. Assessment of impacts of the ongoing land reclamation is in urgent need. Since land use development is related to the well digging, water depth, and quality, it requires the study on the groundwater quality and groundwater levels. 2. The study of the drainage ponds is also an urgent need. Accumulation of drainage water in the desert land will be an obstacle for agricultural development. 3. Further study is required to detect the behavior of the stackholders on the groundwater usage. Especially, the study of the farmers and enterprises that invested on “surface springs” and “investment wells” is required to detect the ongoing process of well development and changes in land use. 4. A full database of existing wells should be available from the irrigation directorate in Dakhla Oasis. This database includes all available information for each well (including depth to water and water quality). This information will help in studying the exact relationship between land use and water quality of the groundwater in the study area.

References Devadas R, Denham RJ, Pringle M (2012) Support vector machine classification of object-based data for crop mapping, using multi-temporal Landsat imagery. Int Arch Photogramm Remote Sens Spat Inf Sci 39:185–190 Hegazy IR, Kaloop MR (2015) Monitoring urban growth and land use change detection with GIS and remote sensing techniques in Daqahlia governorate Egypt. Int J Sustain Built Environ 4(1):117–124 Kato H, Iwasaki E (2008) Rashda. A village in Dakhla Oasis, Egypt. Mediterranean World 19, Hitotsubashi University Kato H, Iwasaki E, Nagasawa E, Anyoji H, Matsuoka N, Kimura R (2010) Rashda: system of irrigation and cultivation in a village in Dakhla Oasis. Mediterranean World 20:1–15 Kato H, Kimura R, Elbeih SF, Iwasaki E, Zaghloul EA (2012) Land use change and crop rotation analysis of a government well district in Rashda village—Dakhla Oasis, Egypt based on satellite data. Egypt J Remote Sens Space Sci 15(2):185–195 Kato H, Elbeih S, Iwasaki E, Sefelnasr A, Shalaby A, Zaghloul E (2014) The relationship between groundwater, landuse, and demography in Dakhla Oasis, Egypt. J Asian Netw GIS-Based Hist Stud 2:3–10 Saleem A, Corner R, Awange J (2018) On the possibility of using CORONA and Landsat data for evaluating and mapping long-term LULC: case study of Iraqi Kurdistan. Appl Geogr 90:145–154

Detecting and Controlling the Waterlogging in Dakhla Basin El-Sayed E. Omran

Abstract Egypt faces a steady decrease in groundwater per capita due to water resource limitations. Land reclamation projects in Egypt are targeted at the Western Desert; however, such expansion involves the best use of land and water resources. The project’s focus is based on knowledge of population growth and food security problems in Egypt. However, waterlogging in these projects’ land is severe. So, the current work was therefore aimed at understanding and detects the waterlogging in Dakhla Basin. Three examples of areas in the desert have been analyzed, Dakhla Oasis, Kharga Oasis, and Farafa Oasis. On the one hand, the ability of the various oases is different depending on the hydrological, socioeconomic and political. On the other hand, permanent irrigation involves constant use of water in the fields that after some time has led to waterlogging. Water-saturated soil allows the distance between the surface and the groundwater table to be small enough to allow water to be brought up by evaporation. The relatively small amount of salt in groundwater can accumulate on the soil’s surface, causing soil salinity to rise over the years. Therefore, a drainage system is needed. In contrast, the most difficult would be the cost of providing sub-surface drainage to the agricultural land in order to prevent the soil from waterlogging. In Dakhla Basin, five major factors responsible for the issue of waterlogging and salinity are identified. Hardpans are the main causes of waterlogging and salinity problems. A second cause is the lack of drainage. The third causes are systems of irrigation. Even the depletion of groundwater quality is the result of over-irrigation. Last but not least, overpumping groundwater is a major contributor to the development of waterlogging in the basin of Dakhla. Keywords Kharga- Dakhla depression · Waterlogging · Basin · Oasis

E.-S. E. Omran (B) Soil and Water Department, Faculty of Agriculture, Suez Canal University, Ismailia 41522, Egypt e-mail: [email protected] Institute of African Research and Studies and Nile Basin Countries, Aswan University, Aswan, Egypt © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_14

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1 Introduction It can be argued that the entire economic dimension of the situation in Egypt is an inevitable consequence of globalization. We decided to concentrate on what can be done internally in Egypt to provide a growing population with food. This should be in relation to the capacity for agricultural production. We must discuss what can be done to help Egypt to once again have a more sustainable food system; thus not as dependent on the global food system as it is now. We will seek to illuminate one dimension that may impact the problem facing Egypt today, bearing in mind that the problem is comprehensive and multifaceted. The Western Desert is aimed at land reclamation projects in Egypt; however, this extension requires the best use of land and water resources. The project’s focus is based on knowledge of population growth and food security problems in Egypt. The main problems facing Egypt are overpopulation, limited arable land and water scarcity (Zidan and Dawoud 2013). It is, therefore important to increase the area of cultivated land (Kamel and Abu El Ella 2016). This is accomplished by reclaiming more land, particularly in the desert, which occupies more than 96% of Egypt’s total area (El-Ramady et al. 2013), but with limited scope for agricultural expansion in the Nile Valley and Delta (Shalaby and Moghanm 2015). The arable land expansion increases domestic production and supports numerous development projects (Adriansen 2009). Major agricultural expansion, industry and civil activities are planned in the Western Desert (Abd El All et al. 2015), which covers 66.7% of the total area of Egypt having seven depressions; Siwa, Qattara, Fayum, Bahariya, Farafra, Dakhla, and Kharga, where the freshwater exists in the oases (Fadl and Abuzaid 2017). On the other hand, due to water resource limitations, Egypt faces a steady decrease in groundwater per capita. The New Valley in Egypt’s Western desert lies in Dakhla Basin which consists of Farafra- Dakhla - Kharga Oases. Dakhla Basin is a major unit of the Nubian Sandstone Aquifer System (NSAS) with huge storage capacity in groundwater. It consists mainly of compacted and broken sandstone with thin clay interbed intercalations. The Nubian Sandstone Aquifer (NSSA), Egypt’s largest aquifer of groundwater, is in this area (Masoud and El Osta 2016). The Nubian aquifer still has a large groundwater reservoir that can help develop the New Valley, respectively. A good water management plan is essential because this Nubian system is not well charged and should be treated as an aquifer for groundwater mining (Mostaf and Hasan 2017). Based on Egypt’s hydrogeological map, a large part of the lower aquifer is exposed in unconfined conditions south of the 26° N parallel. This forms the Nubian Aquifer System. Located in the heart of the Western Desert, Dakhla Oasis has highly fertile land and is the main oasis that supports large population (Kato et al. 2012). How can the population’s demands be meet in relation to agricultural production and be sustainably based on expanding into the New Valley? The main focus is on understanding the potential for agricultural expansion in the New Valley. This extension can be a solution for the growing population of Egypt to increase agricultural production. However, waterlogging is one of the main limitations, which affect agricultural expansion. With this

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issue, we seek to understand the current problems of waterlogging in Dakhla Basin in relation to the potential of Egyptian agriculture in providing a growing population with agricultural products. To sum up; this chapter aims at gaining knowledge and understanding of the waterlogged, which affects the possibilities for agricultural expansion into the New Valley.

2 Study Area 2.1 Kharga-Dakhla-Farafra Depressions The depressions of Kharga and Dakhla are one Depression as they are surrounded by steep escarpments from the east and north without imperceptible breaks and shifts. This mega-depression stretches for about 350 km east-west but has a distance of 200 km north-south along its eastern border in Kharga and about 50 km in Dakhla. Surrounding plateaus rise 300 m a.s.l east of Kharga, 500 m on Abu Tartur, and 300–350 m asl on the northern plateau of Dakhla. From a historical point of view, in classical times, the two oases of Kharga and Dakhla were called “Oasis,” referring together to Kharga and Dakhla as “Oasis Magna” (great oasis), while Bahareya was called “Oasis Parva” (small oasis). Two depressions forming “Oasis Magna” were connected together during the Middle Ages by the caravan route called “El Ghabari,” which is now overridden by the modern asphalt road. Two major rivers ruled eastern Libya, the Sahabi in the west and the Kufra in the east, although the latter seized the former and controlled the paleohyderological network in eastern Libya in the Early Pliocene. The third is a significant conduit of freshwater; the Gilf River, which linked the Uwainat—Gilf high in southwestern Egypt to the north Mediterranean Sea. It may be clear that most of the depressions in the Western Desert, specifically Kharga-Dakhla–Farafa (Fig. 1), are hydrologically connected to this paleo Gilf River. Figure 1 shows the location of Dakhla and Kharga Oases and surrounding landmarks as well as the approximate northeastern boundary (saline freshwater interface) of the Nubian Aquifer (Heinl and Brinkmann 1989; Thorweihe 1990). The Western Desert extends westward from the Nile Valley to the Libyan border with an area of some 681 000 km2 (excluding Faiyum), more than two-thirds of that of Egypt as a whole. For the most part, its terrain consists of a flat rocky plateau and high-lying sandy and stony plains with few distant drainage lines. True mountains can only be seen in the extreme southwest portion where Gebel El-Uweinat’s highest peak is 1907 m. In the northern and central parts of the Western Desert, large depressions and oases to break the surface of the plateau at intervals. Egypt’s topography as showed in Fig. 2 shows that, after obtaining irrigation water, agricultural expansion could be directed mainly towards the Western Desert, which has several depressions along the northern third of this desert, such as the

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Fig. 1 Imagery of Egypt showing the location of Dakhla and Kharga Oases and surrounding landmarks as well as the approximate northeastern boundary (saline freshwater interface) of the Nubian Aquifer

Qattara Depression. The extensive topographical research emphasizes that the AbuTarture plateau is, in fact, a linkage node between the two depressions of Kharga and Dakhla, rather than a separation barrier. Few indigenous elderly people in the area still remember the ancient caravan routes across the back wing of the Abu Tartur plateau, where it links the entire area with Farafra’s third depression until the first quarter of the twentieth century. Ain Amur, Darb El-Tawil, Kharafesh, and El-Dakar dunes were well-known “short-cut” passes (Naqbs) across the plateau’s tabular property, bypassing the lower depression and wetlands, moving faster from Kharga through Dakhla to Farafra. Egypt’s Geological Map shows that this area consists of calcareous (Lower Eocene)/chalk (Palaeocene) as a cap rock for the plateaus, and shale, clay, sandstone (Cretaceous) clastics that shape the floor and the escarpments below the caprock. The bedrocks are unconformably overlain by quaternary fluvial, karst, and aeolian sediments. The natural drainage of underground water from the Nubian sandstone on

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Fig. 2 Digital elevation model of Egypt showing major flats and depressions in the country

the Kharga and Dakhla floors made it easier for prehistoric people to collect, work, and cultivate the Depression’s famous oases. Kharga and Dakhla’s geomorphological maps (Figs. 3 and 4) indicate that they can be split into three geomorphic units: the fringing plateaus, the escarpments, and the floors.

2.2 New Valley Project Egypt’s populated areas make up just 6 percent of the total region of Egypt. Around 99% of all Egyptians live in the Nile Valley. Therefore, Egypt’s rapidly growing growth has needed major investment and people movements from the Nile Valley to the Western Desert. In this situation, the supply of freshwater is a necessary and feasible choice that can fill the wide gap between the capacity available and increasing demands. Geographically, the Western Desert covers 68 percent of the total area of Egypt, including the Mediterranean coastal region and the New Valley.

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Fig. 3 Geomorphologic map of Kharga (Compiled from: Geologic Map, scale 1: 500,000; LandsatTM Images; Topographic Maps, scale 1: 250,000; Field Work) (Embabi 1967)

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Fig. 4 Geomorphologic map of Dakhla (Compiled from: Landsat-TM Images; Topographic Maps, Scale 250,000; Field Observation) (Brookes 1993)

The New Valley plan dates back to 1959, where orders were carried out by former president Gamal Abdel Nasser. His vision was to establish a Western Desert valley, and this valley was intended to be similar to the Nile Valley. Building techniques were implemented, but the project was never completed. The New Valley Project began in the 1960s with five oases: Siwa, Bahariya, Farafra, Dakhla and Kharga (Fig. 5). President Hosni Mubarak, who served from 1981 to 2011 as Egypt’s president, made an ambitious plan in 1997 to create a new parallel to the Nile Valley delta. In the 1990s, astronauts in orbit found many large lakes in the west of the Nile Valley (Brandt 2013). Since the government was only able to release a certain amount of water into the Nile via the Aswan High Dam, transportation of water from Lake Nasser was, therefore, important in order to mitigate the threat of flooding the lake. This water was released into Tushka’s depression, where it first evaporated (Brandt 2013). The developers are hoping to restore the underlying aquifers and create a new, more sustainable area when they built the new Tushka desert lakes. President Hosni Mubarak used the water in 1997 to achieve his goals. The plan will be to build this new delta for the next 20 years, with completion in 2017. The New Valley is expected to increase Egypt’s agricultural land by 10% and provide up to 16 million people with a new living space by 2020, according to the former Egyptian government (Brandt 2013). A new channel has opened, called the Sheik Zayed Canal. This was to pump water from Lake Nasser through the Sheik Zayed Canal, thereby irrigating the desert land of the region. In 2000, 500,000 feddans (1 feddan = 1.03784 acre, 1 feddan = 4200 sq.m, and 1 acre = 4046.86 sq.m)) of land were projected to grow in parallel with the Nile Valley (Brandt 2013).

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Fig. 5 Depressions and Oases of “Dakhla Basin includes Farafra, Dakhla and Kharga Oases.” The Domain for the Dakhla Basin covers an area between Longitudes 27° E and 31.5° E and between Latitudes 24° N and 28° N. The area is 440 km wide by 460 km long

The plan for the New Valley was meant to be the solution for the growing population of Egypt and, therefore, the lack of space. At the same time, it should also help towards food scarcity and issues of poverty, but the project has not been able to succeed in relation to the set goals and expectations. There are only 21,000 hectares of agriculture in 2012, which is less than 10% of the goal (http://www.thenation al.ae). This project appears to know that it is highly uncertain. The lakes are already in trouble because very little water flows into the underlying aquifers. Most of the water is lost due to extreme evaporation of the area. The lakes quickly became salt, threatening the immediately developed aquatic fauna (Brandt 2013). Even though a portion of the big New Valley plan has already been completed in southern Egypt. This portion of the project is called the project of Tushka. In the following, we look at these oases to analyze the water conditions of the NSAS concerning the frequency and quality of water as well as the conditions of management, climate, and farming. In the study, details on the waterlogged area

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will be given for a future discussion if there is a reasonable expansion of agriculture within desert areas.

3 Case 1: Kharga Oasis Kharga Oasis is situated in the central-western desert in the eastern part of Egypt. The position is 140 km East from Dakhla oasis and 220 km to the South of Assiut City and it is bounded by longitude 30° 20 and 30° 40 East and latitude 25° 05 and 25° 30 North (Jahin and Gaber 2011). It is the capital oasis of the New Valley Governorate (Wael et al. 2013), with a population of over 100,000. The climate of the region is hot during the summer, rainfall is rather sporadic and less than 1 mm per year (Jahin and Gaber 2011). July is the warmest month that crosses 40 °C in temperature. High spring winds are common with sandstorms and shifting sand deposits. Groundwater from the aquifer is used for agriculture in this region. Since 1959, all deep wells stopped flowing due to the depletion of groundwater sources by shallow irrigation wells (Jahin and Gaber 2011). The total dissolved solids in water, in general, are below the threshold of the WHO. The pH is between 6.53 and 8.00 and should vary between 6.5 and 8.5 (Jahin and Gaber 2011), and the sodium concentration in groundwater ranges from 20.9 mgL−1 to 138 mgL−1 with a 200 mgL−1 maximum (Jahin and Gaber 2011). It means the groundwater quality is sufficiently high to be used for agricultural irrigation. Research has shown that water levels rise to 140 meters by 2060 in the northern and southern parts of the oasis (Wael et al. 2013). The transmissivity is 509.8 m2 /day on average, and the hydraulic conductivity is 2.5 m/day (Bakhbakhi 2002). Studies and measurements on reliable water levels are necessary, and regulations are required if the oasis in agriculture continues to be economically efficient. Kharga’s depression extends from Aswan to Naga Hammadi, and the plateau at a low level is about 350-400 meters. The lowest average level is between 60 and 80 meters above sea level, and the lowest point is at 2 meters above sea level near the village of Boulaq. The low distance is about 185 km, varying from 15 to 35 km, but it is much longer in the far northwest to 80 km. The north and east edges are wall-shaped and vertical, whereas the low edge is difficult to recognize in the western sense as there are no simple edges to which the floor passes from the lower center to disappear under sand pools that can be considered the upper western edge. The eastern edge is considered the highest and steepest, rising about 400 meters above the low ground on average but north lower than the south. The eastern edge contains calcareous above a shale layer, the calcareous chalk, the Dakhla shale, the phosphatic layers and finally Nubia’s sandstone. The eastern edge cut off a large number of valleys, and these valleys pass through the middle of the Wadis, functioning as their seven natural corridors. There are long, thin dune chains on the west end from north to south. The highest agricultural area of Dakhla, followed by the Farafra, and the least cultivated area of

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Kharga. The flood irrigation system is dominant and the lack of good agricultural drainage has resulted in soil salinization and increased waterlogged soil area. In the eastern region, which has the largest villages, agriculture is typically dominated. Usually, most of Kharga Oasis soil is deep sandy, sandy to deep clay, rocky, sandy, mud-clay sand over deep clay, and shallow mud. Based on hydrogeological studies and projections of computational model for potential horizontal expansion by international, it is not advised to raise reclaimed areas in Kharga as the current cloud (110.30 million cubic meters per year) should not be surpassed for the Byzantine collapse and then the need for self-flowing wells has led to a decrease in the water table.

4 Case 2: Dakhla Oasis Dakhla Oasis (Fig. 6) is located in the Western Desert where approximately 75,000 people live. The only water resource available in this area is the Nubian Sandstone aquifer groundwater. It extends between 25°04’–26° 09 N and 28° 03 –29°39 E, and lies 350 km from the Nile River and between the oases of Farafra and Kharga. It is part of the Dakhla Basin’s broader depression. In Dakhla Oasis there are some important issues related to water need management. There are some contradictions in water law and environmental protection, which is not guaranteed (Ebraheem et al.

Fig. 6 Dakhla Oasis, New Valley Governorate, Egypt

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2004). Dakhla Oasis is one of several structural depressions in the Western Desert (Fig. 6), where Pleistocene pluvial sediments occur as iron-rich spring deposits as well as carbonate spring and lacustrine sediments (Churcher et al. 1999). Dates from Dakhla lacustrine deposits indicate pluvial conditions ranging from 100 ka to 200 ka (Osinski et al. 2007). Nevertheless, a specific geochemical environment from that of the lake high stand has been identified in these previous investigations. Dakhla Oasis is a depression surrounded on its northern side by a steep escarpment running in a generally south-east to north-west direction over a length of approximately 250 km. The Nubian Sandstone complex has a broad geographic distribution within Dakhla Oasis. Shale and clay beds and lenses are needed at the local or sub-regional level for water containment. A thick layer of clay overlays the aquifer network, which acts as an aquiclude, an impermeable layer of water. The field is characterized at a depth of about 1,000 m by rocks in the basement. In general, the composition of rock layers is important to learn about the highly variable water storage potential of various types of rock. The number of wells in Dakhla Oasis is large: over 650 shallow water wells hit the upper aquifer in Dakhla Oasis and over 236 deep wells hit the lower aquifer (Ebraheem et al. 2004). The transmissivity is on average 950.4 m2 /day and the hydraulic conductivity 5.3 m/day (Bakhbakhi 2002). The depth of groundwater throughout the Dakhla Oasis area will not hit the current economic level of 65 m in the next 100 years, even if the current rate of extraction is higher than expected (1.71x106 m3 /day). The economic level gives an idea of the drilling costs associated with the pumping speed. Because of the high drilling and pumping costs, e.g. from electricity prices, the pumping rate limit in the Dakhla Oasis is estimated to be 65 m before it is irrigated economically. In the middle of the oasis, the aquifer’s permeability and thickness are strongly affected by a NorthSouth fault and an anticline bounding from East and West respectively. New well fields should therefore be established in the western part of the oasis (Ebraheem et al. 2004). It is understood that a long-term increase in groundwater extraction is feasible at the Dakhla Oasis. Nevertheless, Ebraheem et al. models predict multiple places to dewater the first aquifer in Dakhla Oasis before the year 2100. Therefore, wells reaching the first aquifer will be dried up (Ebraheem et al. 2004). In Dakhla Oasis, the groundwater quality is generally good and below the safety levels of national and international standards except for enhanced Pb occurrence. The concentration levels of Pb in groundwater samples ranged from 0.06 to 0.17 mg L−1 relative to acceptable values (0.01–0.05 mg L−1 ). The water is slightly acidic (pH 6.09–6.71), whereas the soil is somewhat alkaline (pH 7.95–8.27). When used for medicinal purposes (as per national and international standards), Pb can cause some problems. Consequently, water quality can cause problems with the wells as drinking water sources (Soltan 1997). There are huge areas appropriate for agriculture the western sector represents about three-quarters of the area grown in the oasis, many wells, and land reclamation has spread to the western region of West Mawhub. A lot of villages are scattered in the western region. There are much less developed areas in the eastern sector than the western sector and the number of wells. Dakhla is one of the richest oasis with freshwater resources. In the far east of Dakhla, there are three sites with arable fields

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on the way from it to the outsource, west to east, Al-Aquila Valley, Balizia Valley, and Zayyat Plain. Agriculture is practiced in the low bottom of the plateau, and most of the wells are in the western strip, which comprises several villages. Calcareous, sandstone, and rock weathering created most of the natural soils. In the region, there are also large sandy areas transported from sand dunes by the wind. Most of the currently developed areas are deep sedimentary soil composition. The dominant diagnostic horizon in the region is Salic, Gypsic, and Petrogypsic. There are large areas to be reclaimed and cultivated for the potential for horizontal expansion, especially in the West Mawhub, easily accessible to the Zayyat and some of its neighboring locations, particularly as the Dakhla is regarded one of the richest water reserves. According to hydrological studies and forecasts of mathematical models, the present rate of aquifer production is estimated at 185 million cubic meters and can be increased by 217 million cubic meters per year. The Ministry of Works and Water Resources estimates the capacity to increase for almost 22,000 acres of reclaimed land and to drill 78 wells.

5 Case 3: Farafra Oasis Farafra is a small oasis that is considered to be the New Valley’s most remote oasis. Farafra Oasis lies in the Western Desert between latitudes 26° 00 - 27° 30 N and longitude 27° 20 - 29° 00 E. The Farafra Oasis is situated 170 km from the Bahareya Oasis and 627 km from Cairo and is therefore somewhat isolated. It is described by hyper-arid climatic conditions where the main annual rainfall is 3 mm/year; thus, in Farafra Oasis, groundwater is the unique source of freshwater (Moharram et al. 2011). Figure 7 shows the map of Farafra Oasis. Farafra has a population of around 5000. Most of them, however, came from the Nile Valley to work in the oasis as farmers. Farafra Oasis has some natural water wells because of its geographical location and geological formation. According to Moharram et al. (2011), the 48 productive wells out of 140 wells have an optimum pumping speed of 183,023 m3 /day. Most of the wells are used in the oasis to irrigate the cultivated land. The Post Nubian aquifer exceeds 220 m thick while the Nubian sandstone aquifer is made up of alternating units of sand and clay. These sand units are forming three waterbearing horizons in Farafra (Moharram et al. 2011). The vertical flow of groundwater through the aquifer layers is slowed down in the NSAS clay beds. Nubian aquifer’s low level ranges from—1700 m to approximately—2300 m. The number of wells that tapped this aquifer rose in the present time from 18 wells in the 1960s to about 140 wells. Hence, the pumping from the aquifer was increased in the last decade and now reaches 0.145 km3 /year. The transmissivity of the productive zones in the oasis is recorded between 148.6 and 1642 m2 /day (Moharram et al. 2011), Bakhbakhi (2002) states 1056.8 m2 /day, respectively while the average hydraulic conductivity reaches 1.3–7 m/day, here Bakhbakhi mentioned a value of 4.7 (Bakhbakhi 2002).

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Fig. 7 Farafra Oasis has an irregularly triangular shape and bounded by steep cliffs on three sides

Choosing the latest reclamation areas in the East of Farafra oasis for drilling new wells is highly recommended. We have a high groundwater capacity (Moharram et al. 2011). Increasing groundwater demand in Farafra Oasis has resulted in this source being exploited, causing environmental hazards such as decreasing groundwater levels and

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well intervention. This situation has led to an increasing realization that making groundwater more efficient and sustainable can be accomplished through good management. Moharram et al. utilized models under different scenarios to determine the optimum pumping speed and the number of wells in Farafra Oasis. The findings show that the optimum pumping speed is 183,023 m3 /day in the current situation. The second scenario implies a 20 percent increase in the number of wells. The optimal rate then reaches 220,016 m3 /day. The third scenario suggests an estimated pumping rate of 254,484 m3 /day. This water will be enough to increase the cultivated area by 4000 acres in the oasis (Moharram et al. 2011).

6 Waterlogging in Dakhla Basin Dakhla Basin in the New Valley comprises of three oases, Kharga, Dakhla, and Farafra (Allam et al. 2002). Dakhla is the biggest oasis in the Western Desert and lies farthest away from the main settlements of Egypt. Dakhla is located 122 meters above sea level on average. West Mawhub is the lowest point of the Dakhla Oasis, around 88 m (amsl), and the ground of the oasis slowly rises to the south-east. Altitudes vary between 110 and 140 m above sea level (Kleindienst et al. 1999). Dakhla was originally fed by about 520 springs and ponds, but many have dried out in modern times, while others only operate with electric pumps. Dakhla’s economy relies on agriculture, craft manufacturing, and some tourism. Dakhla must have felt like a world of its own before the road was constructed, where only a few people ever came as far as the nearby oases of Kharga and Farafra. Where there have been no further annual floods due to the construction of the Aswan High Dam, it led to waterlogging and salinization as a result. If the soil around the New Valley is continuously used and cultivated to grow crops throughout the year, the result will be waterlogging. So, a sub-surface drainage system is required to prevent the soil from waterlogging. It would most likely be a very comprehensive way to deal with this negative consequence to outfit the agricultural land throughout the New Valley. If the agricultural land is not well prepared, waterlogging can allow high groundwater levels to occur, resulting in evaporation sucking up the water. This leads to salinization because, by capillary action, salts are disintegrated into the water and drawn to the surface. Then the soil and the water are saltier than before. The purpose of this work is to determine the main causes of waterlogging in Dakhla Basin (Kharga, Dakhla, and Farafra) and to identify the most prone possible waterlogging sites (Fig. 8). Waterlogged areas of the Dakhla Oasis from the year 2017 to 2019 generated through the spatial database created in GIS environment are presented in Fig. 8. Waterlogging and soil salinity threats are closely connected with the spatial patterns of fluvial channels that have been vanquished in the Sahara several thousand years ago since the last wet climatic pluvial. Thus, waterlogging risk can be better understood and thus minimized by remote sensing and GIS mapping the paleohydrological conditions to be included in the development of agricultural field drainage. Satellite information and data obtained from the literature shows the

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Fig. 8 Waterlogged area of the Dakhla Oasis from 2017 to 2019 generated through the spatial database created in GIS environment

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following five main factors responsible for the waterlogging and salinity problem in Dakhla Basin, the observation and physical identification of the waterlogged and salt soil. The primary causes responsible for the problem of waterlogging and salinity are hardpans, which are a dense soil layer located usually below the highest layer of topsoil. There are different kinds of hardpans in Dakhla Basin as claypans and clacipans, all of which share the common characteristic of being a distinct soil layer that is largely water-impermeable. Some hardpans are produced by soil deposits that fuse and bind the soil particles. These deposits can range from silica dissolved to iron oxide and matrices that form calcium carbonate. In the study area, hardpan can be a problem by preventing water drainage and restricting the growth of plant roots. Caliche is a sedimentary rock, a hardened natural carbonate cement that binds other materials like gravel, sand, clay, and silt. A claypan is a thick, compact, gradually permeable layer in the subsoil with a much higher content of clay than the surrounding material from which a sharply defined boundary separates it. Usually, when dry, claypans are hard, and when wet, plastic and sticky. They limit or slow down the movement of water through the soil. Inadequate drainage is a second cause. Waterlogging, of course, depends mainly on soil physical properties, depth and slope, and subsoil bedrock properties, but the position of natural drainage patterns in closed and playa drainage basins is an important factor. Where there is essentially irrigation-excess water and sub-surface flow, it will accumulate under cultivated playa surfaces, especially if an impermeable rock underlines it. Some of the main causes of irrigation system misrepresentation are lack of surface and sub-surface drainage, poor drainage system maintenance, over-irrigation and increasing water-intensive plants. While both the formulation of irrigation projects and drainage should go hand in hand, drainage as an essential component was not given the attention it deserved. Given the low topography of the Oasis and the lack of any natural streams in some places and rainwater falling over the land, excess irrigation water in the absence of proper drainage percolates continuously down raising the water table. The sand ridges covering the whole district were flattened for agriculture. Because of its natural slope, these ridges enabled rapid drainage of excess rainwater. The third cause is faulty irrigation systems. The depletion of groundwater quality also results from over-irrigation. The soil profile percolating water contains most of the salts left behind by the phenomenon of evaporation and transpiration. As water passes through the soil’s profile, extra salts can be dissolved. In addition, some salts may be precipitated in the soil, while some salt ions are transferred in the water added to the soil. Proper irrigation involves applying only enough water to re-wet the soil where the crops have removed it, but not so much that the soil just above the hardpan begins to waterlog. When the soil in which they emerge is waterlogged, the roots soon die. Lastly, groundwater overpumping is a major contributor to waterlogging growth in Dakhla Basin. Like all oases, water is Dakhla’s key component. Prehistoric lakes once occupied the majority of this oasis’ agricultural area. In the hope of establishing

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a fishing industry, an artificial lake was built just north of Mut, but the main source of water remains the wells. This depression is marked by deep wells. Like in Kharga, they are drilled to great depth so that Nubian sandstone can contain water. There were 420 ancient wells at the beginning of the twentieth century, known by the natives as Ain Romani, and 162 modern wells in the plural called bir or abyar. Rohlfs claimed in 1874 that a Hassan Effendi had drilled sixty wells in Dakhla in thirty years, originally collaborating with French mining engineer LeFevre (Cassandra 2002). The wells are just the first component of the irrigation system, as farmers also have to build irrigation canals to carry the water to the fields. Today in Dakhla, there are 600 wells with more on the way. Creating a new well takes one million Egyptian pounds. However, the springs and wells contain iron, magnesium, sulfur, and chloride and are perfect for rheumatism, colds, skin diseases, and kidney stones in their healing water. Today’s Nubian Sandstone Aquifer System (NSAS) water pumping practice is not known because of the scarcity of data and information. It is not certain that the aquifer will be revived or that the pumping will only be based on ancient water. The numerous papers that focus on Dakhla Basin often have conflicting information; the scarce data are with wide ranges and often focused on very limited measurements. The aquifer is only superficially mapped and not mapped on a small scale, which might be appropriate, for example, to position sensitive wells. Data on groundwater production and water management in many oases is very limited. It was very difficult to find basic information. There are some papers on hydrogeological results, of course, but they are often very detailed and do not address fundamental water potential questions. Unfortunately, the impacts of extensive groundwater production involve increasing water level fall, depletion of aquifer reserves, and degradation of groundwater quality. However, there are growing concerns about the aquifer’s safe yield production due to the negligible to restricted aquifer recharge and the rapid growth of agricultural areas. These new agricultural areas are being developed on large areas mainly available in expansive playas, plain sand outwash formed on the border scarp foot slope and the depression ground. For instance, as a result of overpumping, the deep Nubian Sandstone aquifer for irrigation, the groundwater levels in Dakhla Oasis are gradually reduced by a rate of 1 to 4 meters per year. However, soil fertility is significantly impaired by high unfavorable drainage conditions and unsuitable agriculture and irrigation techniques have resulted in extensive soil logging and salinization (Khouri 2003). Despite the drainage problems, large areas of depression have already been irrigated, hoping that the natural drainage capacity of the deep sandy soil profiles will be adequate to control the growth of soil water tables.

7 Conclusions The study area (Dakhla Basin) is located in Egypt’s Western Desert, which includes three Oases, Farafra, Dakhla and Kharga. It lies between latitudes 24° to 28° N and

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longitudes of 27° to 31.5° E. The main objective of this research is to detect the waterlogging in. Three examples of areas in the desert have been analyzed, Dakhla Oasis, Kharga Oasis, and Farafa Oasis. Depending on the hydrological, socioeconomic and political, the capacity of the various oases is different. First, Dakhla Oasis is a relatively large oasis with 350 km from the Nile River. Aquifer extraction has already had some environmental impact. If the current rate of extraction were raised, the economic level of 65 meters below ground level would still not be reached. The groundwater quality in this oasis is generally good, and this means that the agricultural area in this oasis could be increased. Second, Kharga Oasis is located 140 km east of the Dakhla Oasis. The quality of the water is good but the extraction is already so high that it has repercussions and the water level has deteriorated as a result. The third, Farafra Oasis is located 627 km from Cairo and has some natural wells and 140 active wells, and there are good opportunities to expand the agricultural areas east of Farafra, but it has resulted in environmental dangers and diminishing groundwater level due to poor placement of wells. Permanent irrigation requires continuous use of water in the fields, which contributed to waterlogging after some time. Soil saturated of water causes the distance between the surface and the groundwater table to be sufficiently small to allow evaporation to bring water up. The relatively small amount of salt in groundwater can now settle on the surface of the soil, allowing for an increase in soil salinity over the years. Gradually, salinization impacted the plant and soil. Therefore, a drainage system is needed to prevent crop and land deterioration. There is more or less no rain in the desert, and there is extremely high evapotranspiration, so the only source of water comes from groundwater. Furthermore, the costs to provide the agricultural land with sub-surface drainage, in order to prevent the soil from waterlogging and to provide the soil with enough nutrition would most defiantly be enormous. Five major factors responsible for the waterlogging and salinity issue in Dakhla Basin are identified. Hardpans are the main causes of the problem of waterlogging and salinity. The insufficient drainage is the second cause. The third cause is irrigation systems. Even arising from over-irrigation is the depletion of groundwater quality. Last but not least, groundwater overpumping is the major contributor to waterlogging development in Dakhla Basin.

8 Recommendations and Potential for Future Even though each oasis needs to be seen as an entity, as they all display slight differences in the waterlogged area, salinity and water quality. In these oases, however, the cultivated area can be extended. The main problem within expanding the oasis may not be the amount of water, because if there is sufficient money available for high-tech wells, a large amount of water can be pumped out of NSAS. But a good management practice must be implemented again in order to use the extracted water sustainably and prevent waterlogged areas. For example, bad positioning of the wells leads to

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environmental hazards and water level decline. The main problems are environmental threats such as salinization, not the amount of water available. Further research is needed to better examine the many different problems, and good management strategies have to be done in order to realize growth in the desert. If not, Dakhla Basin area could end up highly waterlogged as an unsustainable project. Also, looking at the political, economic and sociological dimensions of food shortages and agricultural production would be an interesting approach to further research into the growth of the basin and agricultural expansion in particular. Finally, waterlogging and soil salinization are a significant threat to housing and oasis development. An extensive waterlogging threat existed because when developing new agricultural areas, the geomorphological and management setting was not recognized. The future direction could be the data. The data on water management in many oases are very limited. It was very difficult to find basic information about population numbers, land use types of agricultural use and land distribution, the agricultural system, which was interesting for us, but it could not be found. There is no public access to this information or that the data simply does not exist. There are some papers on hydrogeological results, of course, but they are often very detailed and do not address fundamental water potential questions.

References Abd El All E, Ahmed K, Taha R, Salah O (2015) Geophysical contribution to evaluate the subsurface structural setting using magnetic and geothermal data in El-Bahariya Oasis, Western Desert, Egypt. NRIAG J Astron Geophys 4:236–248 Adriansen H (2009) Land reclamation in Egypt: A study of life in the new lands. Geoforum 40:664– 674 Allam A, Saaf E, Dawoud M (2002) Desalination of brackish groundwater in Egypt. Desalination 152:19–26 Bakhbakhi M (2002) Hydrogeological framework of the Nubian Sandstone Aquifer System. Regional Coordinator Nubian Sandstone Aquifer System (NSAS) Programme, Proceedings of the International Workshop, Tripoli, Libya 2–4 June 2002, 178 Brandt J (2013) Irrigation technologies and agricultural expansion into the New Valley, Egypt. Semester project. Module: Geography. University of Roskilde Brookes I (1993) Geomorphology and Quaternary geology of the Dakhla Oasis Region. Egypt Quat Sci Rev 12:529–552 Cassandra V (2002) The Western Desert of Egypt. The American University in Cairo Press Churcher CS, Kleindienst MR, Schwarcz HP (1999) Faunal remains from a Middle Pleistocene lacustrine marl in Dakhleh Oasis, Egypt: palaeoenvironmental reconstructions. Palaeogeogr Palaeoclimatol Palaeoecol 154:301–312 Ebraheem AM, Riad S, Wycisk P, Sefelnasr AM (2004) A local-scale groundwater flow model for groundwater resources management in Dakhla Oasis, SW Egypt. Hydrogeol J 12:714–722 El-Ramady H, El-Marsafawy S, and Lewis LN (2013) Sustainable agriculture and climate changes in Egypt. In: Lichtfouse E (Ed) Sustainable agriculture reviews. Springer, Dordrecht, The Netherlands, p 12 Embabi, N. (1967). A geomorphologic study of Kharga Oases Depression, the Western Desert, Egypt. Dissertation, Bristol University

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Fadl ME, Abuzaid AS (2017) Assessment of Land Suitability and Water Requirements for Different Crops in Dakhla Oasis, Western Desert, Egypt. Int J Plant & Soil Sci 16:1–16 Heinl M, Brinkmann PJ (1989) A groundwater model of the Nubian aquifer system. Hydrol Sci J 34:425–447 Jahin HS, Gaber SE (2011) Study of Groundwater Quality in El-Kharga Oasis, Western Desert, Egypt”. National Water Research Center, El-Kanater, Egypt. Asian J Water, Environ Pollut 8:1–7 Kamel M, Abu El Ella E (2016) Integration of remote sensing & GIS to manage the sustainable development in the Nile Valley Desert fringes of Assiut-Sohag Governorates. Upper Egypt J Indian Soc Remot 44:759–774 Kato H, Kimura R, Elbeih S, Iwasaki E, Zaghloul E (2012) Land use change and crop rotation analysis of a government well district in Rashda village—Dakhla Oasis, Egypt based on satellite data. Egypt J Rem Sens Space Sci 15:185–195 Khouri J (2003) Sustainable development and management of water resources in the Arab Region. Dev Water Sci 50:199–220 Kleindienst MR, Churcher, CS, Mcdonald MMA, Schwarcz HP (1999) Geography, geology, geochronology and geoarchaeology of the Dakhleh region: an interim report. In: Churcher CS, Mills AJ (Ed), Reports from the survey of the Dakhleh Oasis 1977–1987. Oxford, Oxbow Books, pp 1–54 Masoud MH, El Osta MM (2016) Evaluation of groundwater vulnerability in El-Bahariya Oasis, Western Desert, Egypt, using modelling and GIS techniques: A case study. J Earth Syst Sci 125:1139–1155 Moharram SH, Gad, MI, Saafan TA, Khalaf Allah S (2011) Optimal groundwater management using genetic algorithm in El-Farafra Oasis, Western Desert, Egypt. Springer Science + Business Media B.V., Water Resour Manage 26. Mostaf A, Hasan TM (2017) Evaluation of groundwater potential in the Dkhla Basin: Farafra-Dakhla -Kharga Oasis. Int Water Technol J, IWTJ 7 Osinski GR, Schwarcz HP, Smith JR, Kleindienst MR, Haldemann AFC, Churcher CS (2007) Evidence for a 200–100 ka meteorite impact in the Western Desert of Egypt. Earth Planet. Sci. Lett. 253:378–388 Shalaby A, Moghanm F (2015) Assessment of urban sprawl on agricultural soil of northern Nile Delta of Egypt using RS and GIS. Chinese Geogr Sci 25:274–282 Soltan ME (1997) Evaluation of groundwater quality in Dakhla oasis (Egyptian western desert). Environ Monit Assess 57:157–168 Thorweihe U (1990) Hydraulic characteristics in the Nubian Aquifer system of the eastern Sahara. International Conference on Groundwater in Large Sedimentary Basins. Australian Water Resources Council, Perth, pp 278–287 Wael EM, Kunio W, Ashraf A, Zahr E (2013) Analysis of groundwater flow in Arid areas with limited hydrogeological data using the Grey Model: a case study of The Nubian Sandstone, Kharga Oasis, Egypt. Hydrogeology Journal 21:1021–1034 Zidan M, Dawoud M (2013) Agriculture use of marginal water in Egypt: Opportunities and challenges. In: Shahid SA, Abdelfattah MA, Taha FK (Ed.) Developments in soil salinity assessment and reclamation: Innovative thinking and use of marginal soil and water resources in irrigated agriculture. Springer, Dordrecht, The Netherlands

Hydrogeophysical Investigations Using DC Resistivity Survey to Assess the Water Potentialities of the Shallow Aquifer Zone in East of Dakhla Oasis, Egypt Khaled S. Gemail, Alaa A. Masoud, Mohamed M. El-Horiny, Mohamed G. Atwia, and Katsuaki Koike Abstract In the Egyptian Western Desert oases as an example of arid environment, groundwater is considered the key source for agricultural and national development projects. The Dakhla Oasis has been a part of the national agriculture projects in the last years therefore, the unplanned pumping of groundwater leads to dropping of water table in the shallow wells. In such cases, the sustainable management and continuous assessment of groundwater is considered as a noteworthy challenge to reduce the impact of the excessive exploitation from the upper zone of the Nubian aquifer system. The present work aims to assess the groundwater potentialities in the shallow aquifer which is structurally controlled by faults. In this study, the DC resistivity sounding survey was integrated with borehole logs and TDS data to delineate the impact of the local faults on the recharge system and water quality in the shallow wells, east of Dakhla area. Forty-Six Schlumberger resistivity soundings were measured to determine the geometry, position, and properties of the upper aquifer zone in the area. In addition, sixteen borehole logs were employed to adjust the resistivity models and determine the accurate boundaries of subsurface layers. The obtained resistivity models were integrated with TDS measurements of the collected water samples from 60 water wells to assess water quality in the upper aquifer zone. Geoelectric cross-sections have been developed to represent plainly the diverse lithologic units and the structural components (essentially faults). Moreover, the inferred true resistivity map of the aquifer layer reflects the water quality and demonstrates that this aquifer resistivity ranges from 11.4 to 337 .m indicating fresh to brackish nature. The anomalous TDS of shallow groundwater in southern parts is referred mainly to, the drained irrigation water (unconfined aquifer) and the low values of K. S. Gemail (B) Environmental Geophysics Lab (ZEGL) at Geology Department, Faculty of Science, Zagazig University, 44519 Zagazig, Egypt e-mail: [email protected] A. A. Masoud · M. M. El-Horiny · M. G. Atwia Geology Department, Faculty of Science, Tanta University, 31527 Tanta, Egypt K. Koike Department of Urban Management, Graduate School of Engineering, Kyoto University, 615-8540 Kyoto, Japan © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_15

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transmissivity which retards the velocity of groundwater up-flow through vertical faulting zones and lead to the increasing of leaching processes of salts. Keywords Groundwater potentialities · Nubian Sandstone Aquifer · Schlumberger resistivity sounding · Dakhla Oasis · Hydrogeophysics · Borehole logs

1 Introduction Recently, great awareness has been focused towards agricultural improvements and sustainable development in the Egyptian deserts as in the southern parts of the Western Desert. In these arid regions, the groundwater from Nubian Sandstone Aquifer System (NSAS) is the only sources of water, hence the groundwater system needs suitable assessment and management procedures for their permissible use and to secure sustainable development. Certainly, abuse of groundwater from NSAS without suitable management strategy caused serious degradation of water and soil in the whole area (Amjath-Babua et al. 2016). As in the present case of NSAS which is considered as a non-renewable resource for groundwater, the understanding of the aquifer characterization and its boundaries is critical to evaluate groundwater potentialities for the planned usage and the impact of misuse and overuse of the resource and environment (Foster and Loucks 2006). Due to the unplanned management of water, the Dakhla Oasis in the Western Desert is experiencing continual depreciation in groundwater level which induces intense soil salinization leading to decline the quality and productivity of affected resources (Masoud et al. 2018, 2019; Kimura et al. 2020). Such environmental issues has occurred due to the rapid growth of agricultural activities in the area that greatly increased the use of groundwater. Therefore, it is significant to recognize the aquifer characterization in Dakhla Oasis ceaselessly to characterize the areal distribution of aquifer layers in the area and determine the groundwater potentialities. Surface geophysical methods can offer an essential role in exploration of groundwater at different depths, as it might offer a method for tending to groundwater potentiality and quality, by giving a spatially broad, non-invasive method for researching the subsurface structures. DC resistivity is one of the most geophysical methods employed for prospecting and assessment the subsurface conditions in hydrogeophysical investigations (Frohlich and Urish 2002; Gemail 2015; Gemail et al. 2016). The Schlumberger vertical sounding technique is regularly employed in groundwater investigations to determine the relatively high saturated zones based on the resistivity patterns at depths down to 500 m. The method may also provide an indication of groundwater quality based on the resistivity variations. Moreover, the DC resistivity sounding technique offers suitable penetration depths and quantitative consequences to understand the groundwater potentiality in the different aquifer conditions. The advantages of this low-cost technology and helpful application in groundwater studies

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are delineation of depths, thicknesses, and aquifer boundaries, in addition to determination of saline and freshwater boundaries and contamination level in groundwater (Zohdy 1989; Gemail et al. 2004, 2017). The present objective is to evaluate the groundwater potentialities using an integrated approach of DC resistivity sounding survey, boreholes information, and TDS data collected from topmost aquifer zone of Nubian Sandstone aquifer. Moreover, delineating the impact of normal faults on the recharge of the upper aquifer zone and consequently the groundwater potentials as a tool for future groundwater management in the area. This type of study will support the decision makers to preserve and manage the groundwater potentialities in such an arid region.

2 Geological and Hydrogeological Setting The present case study is located to the east of Dakhla Oasis in the Western Desert of Egypt as shown in Fig. 1. Based on the aridity index of the United Nations Environment Program (UNEP 1997), the area is considered as arid to hyper-arid environment with no annual precipitation, and a high rate of evaporation (Ismael 2015). Most of natural springs and shallow water wells in the Dakhla area are dried out due to misuse of groundwater for irrigation activities (Sefelnasr et al. 2014). According to Ghoubachi (2001), Dakhla Oasis can be subdivided into three main distinct geomorphologic units as shown in Fig. 2. To the north, the high limestone plateau is bounded the Dakhla Oasis which is defined by a widespread irregular

Fig. 1 Landsat image of Dakhla Oasis and the surveyed area produced from the RGB false-color composite of the 2017 Landsat-8 (Bands7-5-1)

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Fig. 2 Structural and geomorphic map of the Dakhla area in the Western Desert, Egypt (after Hermena 1990)

relief with a rash cliff plunging to the northern region. The Dakhla basin is shaped by erosion forming several landforms such as the piedmont flats, alluvial terraces, and residual hills. To the south of the limestone plateau, the plain comprises sand dunes and several isolated hills reflecting the distinctive weathering of the Nubia Sandstone, which is affected by structures (mainly normal faults and fractures, Fig. 2) and hydrothermal solutions. The Dakhla depression is also affected by series of normal faults of local extension running in a NW-SE, NE-SW and nearly N-S trends forming structural horsts and grabens in-between. These faults are nearly parallel to the axes of the folds detected within the region (Fig. 2). As illustrated in the stratigraphic sequence of the area (Fig. 3), the Nubian Sandstone group belongs to the Upper Jurassic–Campanian period, are composed of ferruginous sandstone with shale interbeds that directly cover the Pre-Cambrian basement rocks. The Nubian Sandstone rocks in the area are distinguished into several formations including Six Hills Fm at the bottom following by Abu Ballas Shale, Sabaya Sandstone, Maghrabi Shale, and Taref sandstone with shale thin beds which is considered as the topmost aquifer zone in the area (Fig. 3). The cap zone is represented by Mut Shale, which consists of multicolored shales and siltstone, and widely covers the whole area with varying thickness. In the depression floor, the Quaternary

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Fig. 3 General stratigraphic sequence and litho-facies of Dakhla Oasis (after Heinl and Thorweihe 1993)

sediments are represented by alluvial deposits, sand dunes, playa, and salty deposits (Sabkha) in southern parts of the area (Ebraheem et al. 2004). From hydrogeological point of view, the Nubian aquifer (NSAS) is considered to be one of the most important freshwater aquifer system in the world. It spreads over a vast area in the southern parts of Egypt and Libya (Fig. 4). As indicated in the hydrogeological cross section of the lower part of Fig. 4c, NSAS is composed of different saturated coarse-grained sand layers confining with shale interbeds that

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Fig. 4 Spatial distributions of Nubian Sandstone Aquifer System (NSAS). (A) Spatial distribution of the NSAS and the Post-Nubian Aquifer System PNSAS (Abotalib et al. 2016), (B) Simplified hydrogeological section along profile A–A’ plotted in Fig. 4A (modified from Thorweihe 1990), and (C) Hydrogeological cross-section in Dakhla sub-basin

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are horizontally and/or vertically interconnected through faulting system (CEDARE 2002; Foster and Loucks 2006). The water bearing formations of NSAS are involved Taref (topmost), Sabaya, and Six Hills formations. The flow direction and water tables in the topmost aquifer zone of Taref Formation are certainly fluctuated by the unplanned and intensive pumping that lads to degradation of shallow wells in the Dakhla and other places (Kato et al. 2014). The Taref aquifer (upper zone of NSAS) is characterized by high effective porosity of 25% in the topmost part and decreases with the depth due to increase of clay contents and ferruginous cementation as indicated from borehole logs. The transmissivity values in this zone varies between 400 m2 /day in the eastern regions and 550 m2 /day in the western parts due to the high sand content compared with the clay content (Borelli and Karanja 1968; Ghoubachi 2001). The Sabaya aquifer showed an average thickness of 300 m while the deeper Six Hills aquifer attained more than 900 m with overall increase to the west and south (Korany et al. 2002). This variation in the aquifer thickness is mainly attributed to the impact of normal faults which throws towards the south and west directions. The peizometric surface above the mean sea level in the area is varied between 118 m, 111,and 135 m in Taref, Sabaya, and Six Hills aquifers, respectively (Gad et al. 2011). In the shallow wells, the depth of water level from the ground surface varies from 8 m at well no. 58 in the southern part to 40 m at well no. 30 in the northern part. The piezometric levels of the aquifer range between 129 m (.a.s.l) in wells no. 58 and 57 at the extreme southern portion of the area and 84 m in wells no. 26 and 22 at the central part. The flow direction in this aquifer is mainly from the north and south parts towards the center of the area (Fig. 5). In several regions, pumping of groundwater from the NSAS reserves is currently taking place and increasing yearly. This has forced the water level to decline progressively (Fig. 6). Consequently, over 35% of the free-flowing wells and springs in many locations had to be deepened or substituted with deeper wells (CEDARE 2002). As an immediate consequence of the groundwater extraction of the Nubian aquifer, a lot of environmental impacts are expected as an outcome (Puri et al. 2001; ElRawy and Smedt 2020). In addition, successive lowering of the groundwater level directly affects the hydraulic parameters of the aquifer like the transmissivity and the groundwater quality suffers noticeable variation as in the present case study.

3 Methodology A total of 46 Vertical Electrical Soundings (VES) were carried out using the Terameter of SAS-300C with the Schlumberger array (Fig. 7). The current electrode spacing (AB) was gradually changed in sequential steps starting from 3 m to 1400 m. This spreading is long enough to penetrate the Maghrabi clay as maker bed and reach the second aquifer zone of Sababya Formation as indicated from the available boreholes information. The measured soundings were scattered to cover the whole area and were marked using GPS instrument. Some measured soundings were located beside

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Fig. 5 Spatial distribution of the piezometric surface of the Taref aquifer in Balat and Tenieda area, East of Dakhla Oasis

Fig. 6 Fluctuation of groundwater piezometric surface in Balat and Tenieda area, East of Dakhla Oasis (2000–2017)

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Fig. 7 Topographic map showing the location of VES stations, water samples, borehole logs and the proposed E-W and N-S geoelectrical section

known lithologic sequences from boreholes to outline the calibrated resistivity of the subsurface horizons by correlating the resistivity measurements with the lithological and hydrogeological data and also finding key relationships between resistivity and groundwater characteristics. In some places as in the southern parts of area the surface layer was resistive ferruginous sandstone and to provide good electrical contact with the ground, some precautions were considered during the field measurements, such as burrowing a hole for each electrode, putting water around the used electrodes and increasing the number of current electrodes on both sides, particularly at large distances. Quantitative interpretation was performed on the measured Schlumberger soundings to obtain the interpreted resistivity and depths of subsurface layers using IPI2win software (Bobachev et al. 2003). An important advantage in this program is that, the resistivity data along a profile are processed as a unit considering the subsurface geological structure of the surveyed area rather than a set of independent objects. During the inversion process, the principle of equivalence was considered, where

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the same resistivity curve may produce many interpreted curves (Koefoed 1979). Depends on the geologic information and the available data of 16 boreholes (Gamma ray and resistivity logs), a good initial model was suggested during the inversion process by. During these procedures, some layer parameters were fixed based on the available layer thicknesses which obtained from the close borehole information as a ground truth. In addition to the DC resistivity field survey, sixty water samples were gathered from the shallow well pumping from Taref aquifer (60–120 m) to cover the whole area (Fig. 7). Using typical calibrated field equipment, the pH, Temperature (T), Total Dissolved Solids (TDS) and Electrical Conductivity (EC) were tested in field. The GPS system of GARMIN GPSMAP 60Cx, was used to verify the geographical coordinates of each sample points.

4 Results and Discussion 4.1 Aquifer Characterizations Resistivities of geological materials vary over a wide range, based on mineral composition, degree of saturation, clay content, and TDS (McNeill 1980; Edet and Okereke 2002). The resulting 1D resistivity models were calibrated with the lithologic unites from the nearby boreholes. Figure 8 shows examples of the correlation between sounding points 8 and 19 with B-45 and T-9 boreholes, respectively (for location see Fig. 7). Depending on this calibration, a spectrum of resistivity for the different lithologic units in the studied area; could be delineated as listed in Table 1. To illustrate the aquifer geometry and the layer distributions in the area, four geoelectrical sections were created in N-S and E-W directions based on the interpreted resistivity data and the lithological information from the available boreholes (Figs. 9 and 10). Four resistivity layers are recognized based on the analysis of the constructed section. The topmost geoelectric layer consists of thin layer (average 1.5 m) and corresponding to sand, silt and clay with widely ranges of resistivity (17125 .m) from the north to the south where the ferruginous sandstone is exposed in the southern parts. The second geoelectric layer representing the Mut Formation that composed mainly of shale and act as cover overlying the Taref aquifer. This layer has an average thickness of 24 m with resistivity average of 11 .m. The thickness of Mut layer increases significantly towards the north and north-east directions, while, it thins or locally absent completely towards the south giving rise to the next geoelectric zone (Taref Formation). The third geoelectric layer varies in thickness from 76 to 122 m which is widely distributed in the area and interpreted to coincide with the shallow aquifer of Taref Formation. The Taref water-bearing layer displays a reasonable resistivity values ranging from 11 to 337 .m reflecting gradually sands intercalated with thin clay layers. Along E-W sections (Fig. 9), groundwater was found to be fresh and showed

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Fig. 8 Examples of correlation between the inverted resistivity models and lithologic data from the nearest wells; (a) VES-8 and well B45 and (b) VES-19 and well T9. For location see Fig. 7

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Table 1 Resistivity spectrum and lithology of the obtained subsurface layers in the study area Formation

Rock Types

Resistivity Range (.m)

Surface layer

Surface Deposits (sand, silt and clay)

1–7125

Mut

Variegated, colored shale with siltstone, and flaggy 0.5–80.7 sandstone

Taref

Water bearing sandstone, fine to medium-grained intercalated with shale

11.4–337

Maghrabi

Shale and claystone interbedded with sandstone

1.2–34.4

Fig. 9 Geoelectrical cross-sections A-A’ and B-B’ in the E-W direction. For location see Fig. 7

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Fig. 10 Geoelectrical cross-sections C-C’ and D-D’ in the N-S direction. For location see Fig. 7

a total dissolved salt (TDS) around 135 to 300 mg/l. The thickness of this layer increases towards the west at soundings no. 34 and 38 reaches the maximum values of 117 and 122 m, respectively while its minimum thickness (93 m) is recorded at sounding no 15. Also, some normal faults are inferred between the shallowest zone of the Taref aquifer and the underlying aquifers. These faults control the occurrence and recharge system of groundwater in the area. The optimum conditions for drilling wells of good water quality and reasonable depths are located in the extreme western portions of the sections. On the other hand, the N-S profiles (Fig. 10) are dominated by brackish groundwater zones towards the central and southern parts as shown by the lower resistivity values at soundings 8, 10 and 17 (15, 28 and 11 .m, respectively) and can be interpreted as a result of infiltration of saline water from irrigation activities

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in the surface salty soils where the Mut Shale is thin in this region (Fig. 10). The total dissolved salts measured from the shallow wells in that part raised to 2480, 3290 and 1960 mg/L, respectively. In addition to the presence of some clay deposits within the aquifer materials. Figure 11, shows the aquifer characterization of Taref sand from resistivity and Gamma ray logs which is illustrated the high shale content at different depths (Abdallah 2013). While, the northern region of the N-S profiles is characterized by high electrical resistivity values (176–337 .m) exhibiting a fresh water prevailing (TDS about 138 mg/L). The thickness of the saturated Taref layer is increased gradually towards the north direction from 80 m at VES no. 9 to 110 m at VES no. 2 (Fig. 10). The 4th geoelectric layer has low resistivities ranging from 1 to 35 .m indicating the green to black shale layer of Maghrabi Formation which extends to the maximum depth of investigation. As indicated from borehole logs, the maximum thickness of this layer is about 70 m and acts as base for the overlying Taref sand aquifer and splits it from the underlying deep aquifers of Sabaya Formation. The distribution of thickness and depths of the shallow aquifer is shown in Fig. 12. In which, the north-western part of the area has the highest aquifer thickness (Fig. 12a) with shallow depths (Fig. 12b) in addition to high resistivity values to indicate a good groundwater potentiality as mentioned early in the E-W geoelectrical sections (Fig. 9). The minimum thickness of this layer (75.8 m) is recorded at the eastern part of the surveyed area due to the influence of the NE-SW normal faults. Based on the constructed maps of thickness and depth (Fig. 12) as well as the resistivity sections, the first priority for groundwater potentially can be given to the northwestern parts around sounding points 34, 35, 38 and 39 where the interpreted resistivities reach to the maximum values of water saturated zone reflecting the good water quality with great thickness and low aquifer depths reducing the drilling cost.

4.2 Faults and Recharge of NSAS To visualize the role of normal faults which are act as windows for vertical water flow in the NSAS, the interpreted resistivities with depths from the surface resistivity soundings and resistivity logs (16 boreholes) were employed to construct a 3D visualization model of Taref aquifer. The inverse distance-anisotropic algorithm was applied to construct a 3D block of the whole area using Rockworks software package (Rockware 2014). The anisotropic interpolation of thin strata as in case of clays in Taref Formation was applied for mapping the lateral discontinuities over large areas with infrequent data points (FitzGerald et al. 2009; Gemail 2012). The initial inputs were gathered by sampling of the interpreted resistivity values and elevations of the subsurface layers from both surface resistivity soundings and resistivity logs. As in the present case, the primary goal of the regional geophysical interpretation is to determine the 3D geometry of the effective faults in the aquifer distribution. In the case of considering the top surface of Maghrabi Fm in the area as marker, the accuracy of the model can be evaluated by comparing the guesses with the observed

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Fig. 11 Litho-saturation cross-plot of Taref Formation in the B45 well showing the vertical clay distribution in the aquifer zone and the aquifer characterization (after Abdallah 2013)

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Fig. 12 Distribution maps of the Taref aquifer from resistivity soundings (a) Thickness of the aquifer zone, and (b) Depth to the upper surface of the aquifer layer

structural and geophysical data (Jessell and Valenta 1996). Reasonably, to improve the 3D resolution of the generated structural model, the input geological boundaries of thin lithologic units were obtained from resistivity and Gamma ray logs where the resolution of DC surface resistivity methods decreases with depths. The sampling rate was low in thin clay layers within Taref Formation as indicated from the resistivity logs and increased with depth to explore the sharp stratigraphic boundaries of the subsurface layers. To produce an acceptable mesh during the gridding procedure, the input block dimensions of 10, 10 and 3 m spacing (X, Y and Z, respectively) were used for creating the 3D visualization model. Figure 13 shows a 2D model of resistivity vertical distributions along a profile (E-W) in the northern part of Dakhla sub-basin crossing the NNE normal faults which are common in the area as indicated from the structural map (Fig. 2) and geoelectrical cross sections (Fig. 9). As illustrated in the obtained 2D model, the northern region of the area is practically recharged through the groundwater upflow along a preferred northeast faults. Along these zones, the solidified Nubian Sandstone, extensive brittle deformation, high hydraulic conductivity, and fill-up by flow from the southwest make this region a promising area for agricultural expansion and development where the TDS around 300 mg/l. Figure 14 shows different outlooks of the 3D created model as horizontal slices at different depth and E-W vertical sections. To understand the mechanism of water flow along the shear zone from the deepest aquifer (Six Hills Formation) to the shallow aquifer, the obtained 3D structural model was confirmed with the interpreted major and minor structures from magnetic data along E-W profiles by Ibraheim et al. (2019) as seen in Fig. 15. The inspection of the horizontal slices (Fig. 14a) at the basal parts of Taref Formation (90–120 m depths) shows elongated high resistivity which are alternated with conductive anomalies, extending in the NNE and nearly NW directions reflecting the impact of normal faults in aquifer distributions. These faults are divided the region into practically parallel structural blocks with different width

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Fig. 13 2D resistivity section along E-W profile in the northern part of Dakhla subbasin showing the flow pattern through the faults and connection between Taref aquifer and the lower Sabaya aquifer. For location see Fig. 7

and depths to indicate possible basement uplift structures and connection of Taref and Sabaya aquifers. The deduced resistivity anomalies agree with the interpretation of the regional aeromagnetic map in Dakhla-Kharga area (Fig. 15, Ibraheim et al. 2019). The vertical sections (Figs. 13 and 14b) illustrate the groundwater up-flow from the lower Sabaya aquifer to Taref upper aquifer through the discontinuities in the Maghrabi Formation due to NNW normal faults.

4.3 Resistivity and Water Quality of the Upper Aquifer Zone To understand the resistivity and TDS relationship in the area, the true resistivities and TDS data of the Taref aquifer were processed by converting the groundwater electrical conductivity from collected samples into water resistivities (ρw = 1/σw). Afterward, the formation resistivity (ρe) was interpreted from the surface resistivity soundings and employed to find an empirical relationship between formation resistivities (ρe) and water resistivities (ρw), and subsequently between formation resistivity and TDS. The relationship between resistivity of Taref Formation and water resistivity was plotted as shown in Fig. 16a, and the empirical relationship is obtained by: ρe = 5.804 ρw + 67.48 where ρw is the water resistivity and ρe is the formation resistivity in .m.

(1)

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Fig. 14 3D resistivity visualization showing the groundwater up-flow in the NSAS in Dakhla oasis, (A) Horizontal slices show the flow pattern along the normal faults and hydraulic connections between Taref and Sabaya aquifer, and (B) Vertical E-W section crossing the common NNE-SSW normal faults

The obtained good fit between formation resistivity (ρe ) and water resistivity (ρw) for the shallow Taref sandstone aquifer (R2 = 0.77) exposes that the formation resistivity in the area is strongly controlled by TDS. This observation offers an endorsement of the basis for applying DC resistivity sounding technique to determine the TDS distribution in groundwater at different depths in clean sand aquifers. Other relationships have been established between the laboratory determined total dissolved solids (TDS in mg/l) and the formation and water resistivities. These relations (Fig. 16b) shows a negative correlation represented by the mathematical equation displayed on the top of the figure between these variables. Figure 16c shows the distribution pattern of the true resistivity values of the shallow water bearing formation in Dakhla oasis. In general, the Taref aquifer displays true resistivities variable from 11.7 to 337 .m. As mentioned early in the resistivity sections, the resistivity values are decreased towards the central and southern parts

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Fig. 15 Interpretation of minor and major structures (Ibraheim et al. 2019) along E-W profile overlain regional aeromagnetic map confirming the 3D resistivity model of Fig. 14 where the horst and graben structures are common in the area

Fig. 16 Relationships between formation resistivity, water resistivity and TDS of Taref aquifer: (a) The estimated empirical relationship between formation resistivity and water resistivity, (b) The obtained relationship between TDS and formation resistivity (c) Formation resistivity distributions from surface resistivity measurements, (d) Water resistivity distributions from laboratory measurements of Ec e) TDS distribution from water samples

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to reach its minimum value of 11 .m at VES 17 with increasing to the north and reach the maximum value of 337 .m at VES 11. Decreasing of resistivity can be explained by embedding of clay lenses in that formation and also to the increasing of total dissolved salts in the groundwater from surface infiltration of preached water and absence of the upper clay cap. Based on the plotted TDS versus water resistivity relationship (Fig. 16b), it was shown that the water samples in the northern part of the Taref water bearing zone are characterized by high resistivities and low TDS to indicate a good water quality in this part, while most samples of the southern parts are characterized by low resistivities and high TDS. As mentioned before, low TDS values are primarily recorded along the faulting zone on the depression surface (Fig. 16e), to indicate the direct hydraulic joining between the low TDS deeper aquifers of Sabaya and Six Hills formations. According to Mohamed et al. (2017), the groundwater flow from the south of Dakhla sub-basin is impeded by the Uweinat-Aswan uplift.

5 Conclusions This study was conducted to evaluate the groundwater potentialities and recharge system in the shallow Nubian aquifer (Taref Formation) at the eastern part of Dakhla depression. Geophysical, hydrogeological and borehole data exposed that the NSAS is the foremost groundwater aquifer in Western Desert including Dakhla basin. The groundwater aquifer is considered as the only natural resource for freshwater supply in this area. However, the most water wells suffer from water level reduction in last decades due to over extraction and unplanned pumping from the topmost aquifer zone. Based on the constructed resistivity sections and borehole data, the shallow aquifer (Traef Formation) is covered the northern parts and originated along the normal fault zones, which are possibly linked with the deeper formations of Sabaya and Six Hills aquifers with permeable pathways. The water quality in the Traef aquifer is degraded to the south due to the decreasing in sand and gravels in contrast with shale and evaporate contents in the water-bearing zone. These lithologic variations led to decrease the aquifer transmissivity and increase the salt leaching to the south of the surveyed area. However, the constructed resistivity sections and distribution maps indicate that groundwater might be of good quality in the northern and northwestern parts than the central and southern parts. The established 2D resistivity sections and 3D maps of shallow aquifer zone is a helpful tool for understanding the conceptual flow model in the area and controlling the future wells drilling for freshwater purposes. The DC resistivity sounding technique is widely contributed in delineating the place of such interface, and can be easily employed in similar arid regions. Furthermore, geophysical investigations are suggested by utilizing different techniques with more prominent examination depth to evaluate and study the relationship between deep and shallow aquifers.

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6 Recommendations Based on geophysical and TDS results, the following recommendations can be considered in the area for groundwater management: 1. The most suitable sites for drilling new water wells occupy the northwestern part of the surveyed area around VESes 34, 35, 38 and 39 which shows high resistivity, high thickness and low accessible depth. 2. Establishing groundwater management and simulation models based on the current results of geophysical and borehole logs to adjust the exploitation of groundwater and developing a more effective scenario to determine the optimal pumping rate from the shallow aquifer and reducing the degradation in the quality and quantity of groundwater in the area. 3. Fixing a proper network of irrigation and drainage systems in the southern parts, which will enable optimum use of water with minimum losses and also to void increasing the soil and water salinity as a result of over pumping.

References Abdallah HS (2013) Petrophysical and sequence stratigraphic studies in the Dekhla Oasis Western Desert, Egypt using well logging data. Msc. Thesis, Geology Department, Assiut University, 214 P Abotalib Z, Sultan M, Elkadiri R (2016) Groundwater processes in Saharan Africa: implications for landscape evolution in arid environments. Earth Sci Rev 156:108–136. https://doi.org/10.1016/j. earscirev.2016.03.004 Amjath-Babu TS, Timothy J, Krupnik J, Harald K, Sreejith A, Diana S (2016) Transitioning to groundwater irrigated intensified agriculture in Sub-Saharan Africa: an indicator based assessment. Agric Water Manag 168(C):125–135 Bobachev A, Modin I, Shevinin V (2003) IPI2Win V2.0: user’s guide. Moscow State University, Moscow. http://geophys.geol.msu.ru/ipi2win.htm Borelli M, Karanja J (1968) Kharga and Dakhla Oases determination of hydrogeological and hydraulic parameters. Report presented to Egyptian General Desert Development Organization by Industry project. Zaghreb, Yougoslavia, p 50 CEDARE (2002) Nubian Sandstone Aquifer System Programme, Regional Maps. Cairo Office, Heliopolis, Cairo Ebraheem MA, Riad S, Wycisk P, Sefelnasr AM (2004) A local-scale groundwater flow model for groundwater resources management in Dakhla Oasis. SW Egypt J Hydrogeol 12:714–722 Edet E, Okereke CS (2002) Delineation of shallow groundwater aquifers in the coastal plain sand of Calabar Area using surface resistivity and hydro-geological. J Afr Earth Sci 35(3):433–441. https://doi.org/10.1016/S0899-5362(02)00148-3 El-Rawy M, De Smedt F (2020) Estimation and mapping of the transmissivity of the Nubian Sandstone Aquifer in the Kharga Oasis. Egypt Water 12(2):604. https://doi.org/10.3390/w12 020604 FitzGerald D, Chilès J, Guillen A (2009) Delineate 3D iron ore geology and resource models using the potential field method. 11th SAGA biennial technical meeting and exhibition, Swaziland, 16–18 Sept 2009, pp 227–235

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Foster S, Loucks D (2006) Non-renewable groundwater resources. UNESCO, IHP-VI, Series on Groundwater, No. 10, Paris, 81 pp Frohlich RK, Urish D (2002) The use of geoelectrics and test wells for the assessment of groundwater quality of a coastal industrial site. J Appl Geophys 50:261–278 Gad MI, El Sheikh AM, El Osta MM (2011) Optimal management for groundwater of Nubian aquifer in el Dakhla depression, Western Desert, Egypt. Int J Water Resour Environ Eng 3(14):393–409 Gemail Kh (2012) Monitoring of wastewater percolation in unsaturated sandy soil using geoelectrical measurements at Gabal el Asfar farm, Northeast Cairo, Egypt. Environ Earth Sci 66:749–761. https://doi.org/10.1007/s12665-011-1283-6 Gemail Kh (2015) Application of 2D resistivity profiling for mapping and interpretation of geology in a till aquitard near Luck Lake, Southern Saskatchewan, Canada, Environ Earth Sci 73:923–935 Gemail Kh, Samir Ah, Oelsner Ch, Mousa S, Ibtaheim Sh (2004) Study of saltwater intrusion using 1D, 2D and 3D resistivity surveys in the coastal depressions at the eastern part of Matruh area, Egypt. Near Surface Geophysics, European Association of Geoscientists & Engineers, vol 2 Gemail Kh, Abd-El Rahman NM, Ghiath BM, Aziz RN (2016) Integration of ASTER and airborne geophysical data for mineral exploration and environmental mapping: a case study, Gabal Dara, North Eastern Desert, Egypt. Environ Earth Sci 75:592. https://doi.org/10.1007/s12665-0165368-0 Gemail Kh, El-Alfy M, Ghoneim MF, El-Shishtawy AM, El-Bary MH (2017) Comparison of DRASTIC and DC resistivity modeling for assessing aquifer vulnerability in the central Nile Delta, Egypt. Environ Earth Sci 76(9) https://doi.org/10.1007/s12665-017-6688-4 Ghoubachi SY (2001) Hydrogeological characteristics of the Nubia Sandstone Aquifer System in Dakhla Depression, Western Desert Egypt. M.Sc Thesis. Faculty of Science Ain Shams University, Egypt, 260 p Heinl M, Thorweihe M (1993) Groundwater resources and management in SW Egypt. Catena Suppl. 26:99–121 Hermina M (1990) The surroundings of Kharga, Dakhla and Farafra oases. In: Said R (ed) Geology of Egypt. A.A. Balkema, Rotterdam, pp 259–292 Ibraheim E, Ghazala H, Elawadi E, Alfaifi H, Abdelrahman K (2019) Structural depocenters control the Nubian sandstone aquifer, Southwestern Desert, Egypt: inferences from aeromagnetic data. Arab J Geosci 12:335. https://doi.org/10.1007/s12517-019-4492-z Ismael H (2015) Evaluation of present-day climate-induced desertification in El-Dakhla Oasis, western Desert of Egypt, based on integration of medalus method, GIS and RS techniques. Present Environ Sustain Dev 9(2):7–72 Jessell MW, Valenta RK (1996) Structural geophysics: integrated structural and geophysical modelling. In: De Paor DG (ed) Structural geology and personal computers. Pergamon, 303–324. 10014, 10016, 10018, 10046 Kato H, Elbeih S, Iwasaki E, Sefelnasr A, Shalaby A, Zaghloul E (2014) The relationship between groundwater, landuse, and demography in Dakhla Oasis, Egypt. J Asian Netw GIS based Hist Stud 2:3–10 Kimura R, Iwasaki E, Matsuoka N (2020) Analysis of the recent agricultural situation of Dakhla Oasis, Egypt, Using meteorological and satellite data. Remote Sens. 12:1264. https://doi.org/10. 3390/rs12081264 Koefoed O (1979) Geosounding principles: resistivity sounding measurements, vol 1. Elsevier, Amsterdam, p 276 Korany EA, Hammad FA, Abd El Ati A (2002) An assessment of hydrogeological conditions of Nubia aquifer in Bahariya and Farafra depressions, Western Desert, Egypt. J Environ Res Zagazig Univ 18:1–24 Masoud AA, El-Horiny MM, Atwia MG, Gemail K, Koike K (2018) Assessment of groundwater and soil quality degradation using multivariate and geostatistical analyses, Dakhla Oasis, Egypt. J Afr Earth Sci 142:64–81

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Conclusions

Update, Conclusions, and Recommendations of “Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis” Erina Iwasaki, Abdelazim M. Negm, and Salwa F. Elbeih

Abstract The current chapter highlights the main conclusions and recommendations of the chapters presented in the book. Also, some findings from recently published research work related to Sustainable Water Solutions in the Western Desert, Egypt are discussed. This chapter contains results of some case studies on Dakhla Oasis by natural and social scientists in the field of hydrology, hydrogeology, geology, archaeology, soil science, remote sensing, land use, agriculture, history, and sociology. The topics covered in the book include: geological and hydraulic structures, climatic influence, groundwater management, irrigation management and human settlements. In addition, a set of recommendations for future research work is pointed out to direct the future research for the sake of sustainable development of the oasis. Keywords Sustainability · Dakhla Oasis · New Valley · Environment · Egypt · Agriculture · Water resources · Climate change · Well History

1 Introduction Water scarcity in arid regions is a key challenge for the growing population in Egypt. This is especially for the agricultural sector which consumes almost two thirds of its E. Iwasaki (B) Faculty of Foreign Studies, Sophia University, Tokyo, Japan e-mail: [email protected] A. M. Negm · S. F. Elbeih Water and Water Structures Engineering Department, Faculty of Engineering, Zagazig University, Zagazig 44519, Egypt e-mail: [email protected] S. F. Elbeih e-mail: [email protected]; [email protected] S. F. Elbeih Engineering Applications and Water Division, National Authority for Remote Sensing and Space Sciences (NARSS), Cairo, Egypt © Springer Nature Switzerland AG 2021 E. Iwasaki et al. (eds.), Sustainable Water Solutions in the Western Desert, Egypt: Dakhla Oasis, Earth and Environmental Sciences Library, https://doi.org/10.1007/978-3-030-64005-7_16

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fresh water supply. Ensuring sustainable water resource management is a matter of high priority to the Government of Egypt, for the sake of food security. For the concern of water scarcity in the Egyptian society, which is depending mainly upon the Nile River, Egypt has been conducting land reclamation projects since the 1960s, the most renown of which, and dealt in many chapters of this book, is the New Valley Project launched in the early 1960s. The name of New Valley Governorate lying in the Western Desert owes its name to this large-scale governmental project. Since then, many land reclamation projects were carried out in the Western Desert including Dakhla Oasis. Recently, the Egyptian Government launched a mega project that aims at reclaiming 1.5 million feddan (1 feddan = 1.03784 acre, 1 feddan = 4200 sq.m, and 1 acre = 4046.86 sq.m) in Sinai and the Western Desert including Dakhla Oasis to harvest wheat which is the most important staple food in Egypt. Thus, the New Valley Governorate, in the Western Desert, has been and further becoming strategically an important region in Egypt for food security. However, despite the growing interest for the agricultural development and the strategical importance, much is known about the current environmental situations in the region concerned. Research from various disciplinary approaches is required to study how can the region maintain the sustainability. All chapters in this book share the awareness that the sustainability is the key issue of not only the Western Desert, but also for the entire Egyptian society for securing the staple food. Such awareness led the editors to gather researches on sustainability in the Western Desert, taking Dakhla Oasis which is the most populated oasis in the Western Desert as a case study. Although all the oases in the Western Desert share a common feature that they depend upon the Nubian Sandstone Aquifer, each oasis has its own personality, geological and hydrogeological conditions. This is the reason why the scope of the book is mainly Dakhla Oasis. In the near future, we hope to extend our multi-disciplinary research to other oases in the Western Desert to fully understand the problems and potentiality of the sustainable development based on groundwater in Egypt.

2 An Update The studies presented in this book have different views on the future of Dakhla Oasis. Because of rainfall scarcity, Dakhla Oasis depends on groundwater for human survival. As will be presented in the next paragraphs, in the conclusions section, groundwater, human settlements, land use, archaeological sites, natural heritages, all are subject to man-made hazards. There is an urgent need to assess the state of land reclamation, its environmental impact, and groundwater potentiality in Dakhla Oasis. As will be presented in the last section, many authors are aware of water sustainability. Further researches based on multidisciplinary approaches are required to

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study the human impact on water and environmental sustainability, because environmental and socioeconomic changes observed in Dakhla Oasis are complex phenomena caused by human and water interactions. In guise of “Update”, the rest of this Section overviews the ongoing land reclamation projects in the desert areas that are expected to assure Egypt’s food security. According to the MIIC (Ministry of Investment and International Cooperation), the 1.5 Million Feddan (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) Project aims to increase the agricultural land by 20% by converting desert lands to agricultural lands such as Farafra Oasis, Toshka, El Moghra, and West of Minya regions, in accordance with the Egypt Vision 2030 (Ministry of Investment and International Cooperation).1 Its goal is to to reduce the food gap and increase the populated area through the creation of new urban communities. The Egyptian Countryside Development Company, a holding company established by the ministries, is in charge of this project, and sells or leases the reclaimed lands to the investors (Egyptian Countryside Development Company). It was inaugurated in December 2015 by President El-Sisi as one of three megaprojects in Egypt (Suez Canal extension project, New Capital project). The development areas can be grouped into four categories, based on the hydrogeological setting and the intended source of water; Post-Nubian Aquifer System, Nubian Sandstone Aquifer, Moghra Aquifer and the Nile Aquifer. The government will implement the 1.5 Million Feddan Project on three stages, 500,000 feddans completed in October 2015, as the first phase, over the cities of Farafra and Toshka in the New Valley Governorate and Moghra in Matrouh Governorate (Egypt Today 2019, July 2). Second stage is, New Farafra, West Kom Ombo, West Minya, East Siwa, and Dakhla Extension. The third stage is: Old Farafra, West Minya and El-Tor (Ministry of Agriculture and Land Reclamation 2018). Recently, Egyptian Countryside Development Company approved to sell 900,000 feddans to 14 companies belonging to Egypt, Saudi Arabia, UAE, Kuwait, Cyprus, Greece and Spain in the zones such as Farafra, West Minya, Moghra south to Alamein, and Toshka. The land will be delivered to the companies after operating infrastructure facilities and paving roads (Egypt Today 2019, February 5). To reclaim the desert, land requires drilling of wells to discharge groundwater from Nubian Aquifer which inhabitants of Dakhla Oasis depend upon. The Ministry of Irrigation and Water Resources announced in December 2015 that the project includes digging over five thousand water wells for a total cost of EGP 6 billion ($766 million), with 600 wells to be drilled in different areas of Egypt’s Western Desert, including Moghra, Qattara Depression, Toshka region and Farafra Oasis (Ahram 2015, December 14). The Egyptian Government’s awareness about the sustainability of the Western Desert can be seen in the banning by the Ministry of Water Resources and Irrigation feddan equals 1.038 acres. 1.5 million feddan (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) equals 630,000 ha (USDA Foreign Agricultural Service).

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Fig. 1 Development areas of the 1.5 Million Feddan Project (https://www.elreefelmasry.com/) 2018

to cultivate alfalfa, banana, and rice crops in the 1.5 Million Feddan Project, and to grow any crop with a daily consumption rate of more than 15 cubic meters per day (Egypt Today 2019, July 2). What will be its consequences on the groundwater and environment? Dakhla Oasis is not involved in the project, but it depends on the same aquifer. Egypt is in need to secure food for large growing population, and for this reason, President Nasser launched the New Valley Project in the 1960s, President Sadat launched El-Sahiliya Project which was initiated in 1981/82 to reclaim 23,000 feddan (1 feddan = 1.03784 acre, 1 feddan =4200 sq.m, and 1 acre = 4046.86 sq.m) in East Nile Delta, President Mubarak launched Toshka Project, and current President Sisi the 1.5 Million Feddan Project (Fig. 1).2 However, still more researches are needed to understand how to achieve sustainable development on the desert land and discharging groundwater from the Nubian Aquifer.

2 For

the land reclamation projects in Egypt since 1950s, see Adriansen (2009), Kato and Iwasaki (2016) Chapter 1, Meyer (1994), Voll (1980). For the recent projects, visit the links in the website of Ministry of Warer Resources and Irrgation (https://www.mwri.gov.eg/all-projects/) .

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3 Conclusions The following conclusions are mainly extracted from the chapters presented in this volume: 1.

The average effective active wind speed categories at Dakhla and Farafra oases were measured using the Sand drift potential (DP) formula based on Fryberger model. Authors clarified that spring months showed the highest resultant drift potential on one hand, and stabilization of sand dune movements are very difficult and more expensive, on the other hand. 2. The Qusseir Formation is the oldest rock unit exposed in Dakhla Oasis, underlain by a thick succession of the Taref Formation and overlain by the phosphate bearing rock unit Duwi Formation. The Duwi Formation, on the other hand, is overlain by a thick sequence of Dakhla Formation which is divided into three members, i.e., the Mawhub Shale Member at the base, Baris Mudstone Member at the middle and the Kharga Shale Member at the top. 3. During the middle Maastrichtian time, west Mawhub area was slightly uplifted and due to the environmental changes, Kharga Shale was laterally changed in facies and became sandstone and sandy silt with limestone intercalations in which the term Qur El-Malik Sandstone Member was applied. 4. Dakhla Oasis undergoes different man-made hazards destroying its natural heritage in the land, water, and natural vegetation. There are many examples of problems of over-irrigation and mismanagement of water resources. Most of land reclamation in the study area are going fast at the expense of playa, spring mounds, springs, etc. The last ten years were very dramatic in removing most of the Quaternary natural history of the oasis. 5. Archaeological sites are suffering from all kind of deteriorations, either by natural hazards or man-made ones. 6. Discharging drained water after cultivation is a big problem in many areas inside the depression. The triangle of Ismant—Hindaw—Mut is a visible example for land salinization. 7. The archaeological sites in Dakhla Oasis region provide an example of the alternating wet and dry climatic phases in shaping of the oasis landscapes, ancient civilizations and climate changes. It exemplifies the complexity of the water/life relationship in a spring-mound fed oasis with groundwater. 8. The Urban encroachments in the oases had disastrous effects upon the archaeological sites and cities. As Dakhla Oasis is rich with many archaeological sites from prehistoric to recent times, landscape and natural resources, a special attention should be addressed for the development of these resources for ecotourism and desert safari. 9. Dakhla Oasis climate has the typical characteristics of both desert and oasis, including (a) fine weather, high evapotranspiration, and nearly zero annual rainfall, (b) humidity is high relative to typical arid regions. 10. From the meteorological conditions in Dakhla Oasis, water requirements are highest for date palm and second highest for rice paddy. Water demands for

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winter wheat are comparatively low and those for winter wheat are almost the same as for clover hay. Aanalysis using remote sensing, GIS and climate data technologies highlighted variation of soil properties in Dakhla Oasis, and explained how to use them for optimal use under these conditions. The soils of Dakhla Oasis are highly productive and suitable for most crops. The most predominant limiting factors are salinity, soil depth and topography. Combination of statistical data with geographical information is efficient for the study of oasis societies. Integrating visual interpretation with supervised classification leads to an increase in the overall accuracy of land use/cover classification. Integrating GIS and Remote Sensing provides valuable information on the area and spatial distribution of urban expansion. Dakhla Oasis has undergone significant land cover changes during the past 30 years (1988–2018), with significant increases in urban settlements and agricultural lands, because of population growth and land reclamation. Generally, it was found that the annual rate of agricultural land growth is greater than the rate of built-up land sprawl during the period of study. Despite of that, the built-up area increased by 480.6% (of the built-up area in 1988), and the agricultural land increased by 197.2% (of the agriculture area in 1988). The land use/cover analysis and its relation with groundwater wells using satellite images on Rashda village from 1968 to 2018, showed that although the difficulty of using Corona satellite image of 1968, there was a clear change in land use/cover during the past 50 years (1968–2018). This is mainly brought by the conversion of desert land to agricultural land, and in lesser extent to built-up land. The expansion of agricultural lands in Rashda Village was closely associated with drilling of wells: governmental wells until 1980s, and surface springs from the period after 1988. The latter type of wells started under the economic liberalization by small and medium investors (farmers and enterprises). Thus, it is pointed out that the expansion of agricultural lands in Rashda Village during the observed period (1968 till now) was mainly driven by the investors under the economic liberalization. Well development is associated with complex phenomena, one of which is the increase of water bodies (drainage lakes). Empirical results, measuring the technical and scale efficiency of farmers based on the survey of agricultural households in Rashda village in Dakhla Oasis during 2009, suggest the average scores of technical efficiencies was 17.5% under the CRS assumption, whereas it was 20.2% under the VRS assumption. The estimated efficiency scores of farms in Rashda were generally lower, but they suggest that the level of output can be increased by 82.5% and 79.8% under the CRS and VRS specifications, respectively, using the current levels of inputs. Farmers, mostly small-scale cultivators, prefer to grow more rice and fodder crops despite their low efficiencies and water intensity. This could be understood from the consumption side; i.e., from a household consumption perspective, it is rational to secure the household’s basic food needs.

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19. The Nubian Sandstone basin is tectonically affected by regional faults and is divided into different sub-basins. The salinity of the Nubian aquifer changes vertically and laterally. In general, the recorded salinity decreases with depth in Kharga and Dakhla Depressions, from 1,000 ppm in the upper horizons to 200 ppm in the lower ones. If the geometry of the aquifer is approximated by a triangle, the age of the groundwater is a function of depth. 20. Detailed survey and test drillings together with the intensive oil exploration works in the northern part of the Western Desert made it possible to assess the regional hydrogeologic setting of Dakhla Oasis. Flooding irrigation is one of the main reasons for water consumption in agricultural operations. Drainage networks are one of the main factors that influence the distribution of ponds in the depression. 21. The drastic change of the human relationship with groundwater occurred with the development of modern technology since the late 1950s. The vertical and horizontal exploitations of the groundwater were enabled by the deep-well drilling machines and the development of pumping technology. The technology of water discharge enabled the discharge of a large amount of groundwater and the ability to overcome water deficiency, as did the human control of the Nile River. 22. A consequence of the increased drilling is the lowering of the groundwater level. An informant and other farmers, recalling their childhood during the beginning of the 1990s, said that the artesian wells had functioned well up to that period. The water even came out so strong that it was difficult to close the valve, but since then, it has become easy to do so. Today, all the artesian wells are dried up, and the water can be discharged only by pumping. 23. Although Dakhla Oasis, Kharga Oasis, and Farafra Oasis depend on similar hydrological, socioeconomic and political environments, the capacity of the various oases is different. In regards to Dakhla Oasis, it is a relatively large oasis located 350 km from the River Nile. Aquifer extraction has already had some environmental impacts. If the current rate of extraction were raised, the economic level of 65 meters below ground level would still not be reached. The groundwater quality in this oasis is generally good and this means that the agricultural area in this oasis could be increased. 24. Permanent irrigation requires continuous use of water in the fields, which contributes to waterlogging after some time. The relatively small amount of salt in groundwater can settle on the surface of the soil, allowing for an increase in soil salinity over the years. Gradually, salinization impacted the plant and soil. Therefore, a drainage system is needed to prevent crop and land deterioration. 25. The costs to provide the agricultural land with sub-surface drainage, in order to prevent the soil from waterlogging and to provide the soil with enough nutrition, would most be enormous. 26. Five major factors are responsible for the waterlogging and salinity issue in Dakhla Basin. Hardpans are the main causes of the problem of waterlogging

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and salinity. The insufficient drainage is a second cause. Third causes are irrigation systems. Even arising from over irrigation is the depletion of groundwater quality. In addition, groundwater overpumping is a major contributor to waterlogging development in Dakhla Basin. The oases in Dakhla all display slight differences in the waterlogged area, salinity and water quality. In these oases, however, the cultivated area can be extended. The main problem with expanding the oasis may not be the amount of water, because if there is sufficient money available for high-tech wells, a large amount of water can be pumped out of NSAS. But a good management must be implemented again in order to use the extracted water sustainably and prevent waterlogged areas. The groundwater aquifer is considered as the only natural resource for freshwater supply supplies in this area. However, it suffers from water table depletion due to over exploitation and un-managed withdrawal. Fresh groundwater of the shallow aquifer was dominated in the northern parts and found to be located along the fault planes, which were probably connected to the underlying sandstone aquifers (the Sabaya and Six Hills) with high permeability. The groundwater salinization is enhanced southward because of the decrease in sand content, increase in shale with gypsum and evaporate bands in the aquifer, and the decrease in aquifer transmissivity, which increase the salt leaching by reducing the speed of groundwater flow. Inspection of the obtained geophysical results and correlation with the available geological, and hydrogeologic information revealed that the studied zone is composed of successive layers of graded sand intercalated with thin clay layers and the area is affected by several fault elements striking in different directions and controlling groundwater flow and accumulation. Resistivity distribution maps indicate that groundwater might be of good quality in the northern parts than the central and southern parts.

4 Recommendations The following recommendations are mainly extracted from the chapters presented in this volume: 1.

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Stabilization of moving sand dunes in Dakhla Oasis is very difficult and expensive. Thus, the best way to overcome threatening dunes is to move away of their path, and the new reclamation land should be in between the dune belts. Laser stations are required to monitor the movement of sand dunes in Dakhla depression. It is recommended to study in detail the Duwi Formation as an extension of the Phosphate bearing rock unit in Abu Tartur Phosphate Mining Project in Kharga Oasis. The importance of analyzing the landscape and landforms from a more wider view by comparison with the other geographic regions surrounding Dakhla

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Oasis, and by locating correctly the Dakhla depression within the wider space of Eastern Sahara should be emphasized. Further researches based on multidisciplinary approaches are required to study Dakhla Depression from different specializations of earth sciences. Sand dunes in the study area are a very important issue to be monitored in the future. There are new successful attempts to confront desertification in different parts of the depression (especially through cultivation) but dune fields still threaten the oasis very seriously. Dakhla Oasis needs to improve infrastructure and services that attract people for sustainable development. Development in the oasis lands is one of the solutions to overcome the problem of overpopulation around the Nile Valley and Delta areas. The Government’s decision to move towards increased land reclamation activities in the oases is a good step towards sustainable development. Expansion of agricultural lands in the oasis requires precise understanding of the land and water resources for the optimum use. A study of land suitability maps for different crops in Dakhla Oasis helps in planning sustainable agriculture programs. Dakhla Oasis soils are suitable for most crops, so the area can be exploited in major agricultural projects. In addition, Dakhla Oasis could contribute to supply large quantities of grains crops such as wheat, thus reducing the food gap in Egypt. Dakhla Oasis needs more effort to develop an efficient improvement of infrastructure, education, health and social services. Youth should also be encouraged to invest in this region in the agricultural and industrial sector by facilitating access to credit. The use of modern technology in agricultural production can be promoted by training small farmers and investors on the uses of modern technologies of agriculture. Remote sensing and GIS provide accurate and geo-spatial information about land and water suitability for crop production in addition to water requirements for various crops. Dakhla Oasis is a vast, remote area which is difficult to access, and needs a good management plan for the conservation and protection of the resources for the future generations and the researchers. The laser scanning techniques for the documentation, recording, and presentation by the digital media of the archaeological sites should be encouraged to promote the archaeological tourism in Dakhla Oasis. An additional meteorological station will be needed to manage the irrigation water use in Oasis regions, because of the local climate which change with the geographic features. Recent satellite sensors such as the Moderate Resolution Imaging Spectroradiometer (MODIS), is used to monitor the land surface temperature, vegetation indices, evapotranspiration, and so on. Successors such as the Second Generation Global Imager sensor (SGLI) or the Global Change Observation Mission (Climate) satellite have more highly resolution (250 m) than MODIS, These

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satellite data will cover the shortage of meteorological stations in the Oasis regions. It is advised to apply modern irrigation methods such as pivot, sprinkler and drip irrigation to conserve the limited groundwater and to protect the soil form water logging and salinization. Fixing sand dunes is also necessary to protect agricultural land and infrastructure. It is necessary to establish a full database of existing wells available from irrigation directorate in Dakhla Oasis. This information will help in studying the exact relationship between land use and water quality of the groundwater in the study area. Assessment of impacts of the ongoing land reclamation and well development is in urgent need. It requires the study on the groundwater quality and groundwater level on one hand, and the study of the drainage ponds that is expanding along with the increase in groundwater withdrawal. The study of the drainage ponds is also in urgent need. Drainage water cannot be recycled, and the accumulation of drainage water in desert land will be an obstacle to the agricultural development. Further study is required to detect the actors and their behavior on the groundwater usage. Especially, the study of the farmers and enterprises that invested on “surface springs” and “investment wells” is required to detect the ongoing process of well development and change in land use. A full database of existing wells should be available from irrigation directorate in Dakhla Oasis. This database which includes all the available information for each well (including depth to water and water quality) will help in studying the exact relationship between land use and water quality of the groundwater. Irrigation water is a limiting factor in the oasis region due to the shortage in water resources. Therefore, there is a dire need to determine the adequate quantities of crops to reach the highest levels of crop production. the most efficient way of cultivation is to intensify the cultivation of date fruits. However, the cropping decision should simultaneously consider the requirements for basic food for the household and its animals. Taking Rashda village as a case study, the level of agricultural output could be increased by 79.8% and 82.5% with the current levels of inputs and given technology. More than 24% of farms could increase their production and productivity by increasing their inputs under the current crop cultivation patterns. About 24.1% of farms could improve their efficiencies by reducing their input use. Further study is required on the farmers’ consumption behavior to determine the cropping pattern suitable for household welfare to secure basic foods. Also, further study is required to clarify the water quantity available according to the type of well, and the water requirement of each crop to reach the highest economic returns with water rationalization. It is recommended to put agricultural drainage ponds in the depression under environmental supervision, through preparation of a monitoring system to get the most benefits from those ponds economically, as well as the protection

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of agricultural soil nearby from deterioration due to the processes of salinity increasing of soil and water. Assessment of the hydrological and hydrologeological conditions of the groundwater aquifer (number of wells—discharges—groundwater level—productivity—groundwater chemistry—etc.) is required to further understand the problem of environmental protection in Dakhla Oasis. Conducting a topographic survey is necessary to determine the areas of natural depressions that can be used for drainage ponds to be at a level lower than that of agricultural lands and drains. Geological, hydrogeological and geophysical investigations are required to select the most appropriate locations to recharge the groundwater aquifer with the excess water and to compensate the groundwater reservoir in the areas of wells that are mechanically discharged. A study of irrigation systems in Dakhla Oasis is necessary to change the irrigation systems from irrigation by flooding to sprinkling or drip irrigation, and to reduce water losses and reduce the amount of wastewater received in the drains. The increase of wells was observed with the development of technology whose consequence was the lowering of groundwater level. To further study the consequences, research is required to monitor the groundwater table. An important subject to be studied is the villagers’ perception of groundwater. It seems that the villagers view the problem as a matter of water flow uncertainty, rather than as a risk of exhausting the overall groundwater storage. If the water flow stops from one well, they drill a new replacement well with new well designer. Thus, the drilling of wells continues and has accelerated in recent years to ensure water supply, which will risk the sustainability of life depending on the groundwater. The cultivated area can be extended in Dakhla Oasis. However, a good management must be implemented in order to use the extracted water in a sustainably way and prevent waterlogged areas. For example, bad positioning of the wells leads to environmental hazards and water level decline. The main problems are environmental threats such as salinization, not the amount of water available. Further research is needed to better examine the many different problems and good management strategies have to be done in order to realize growth in the desert. If not, Dakhla Basin area could end with high waterlogged as an unsustainable project. Looking at the political, economic and sociological dimensions of food shortages and agricultural production would be an interesting approach to further research into the growth of the basin and agricultural expansion in particular. Waterlogging and soil salinization are the significant threat in housing and oasis development. Extensive waterlogging could be a large threats to the development of new agricultural areas, unless the geomorphological and management setting is recognized. Detection of final future direction requires the collection of data. The data on water management in many oases are very limited. It is very difficult to find basic information about population numbers, land use types of agricultural use

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and land distribution, the agricultural system. There is no public access to this information or that the data simply does not exist. There are some papers on hydrogeological results, of course, but they are often very detailed and do not address fundamental water potential questions. 37. Developing a more effective plan and design for agronomic management in the area to regulate over-exploitation of groundwater by replacing the outmoded irrigation systems with modern and efficient ones, water reuse for irrigation, and plantation of drought-resistant crops or species. 38. Installing a proper network of irrigation and drainage systems, which will enable optimum use of water with minimum losses and also to void increasing the soil and water salinity as a result of over pumping. 39. Moreover, geophysical investigations are suggested by utilizing different techniques with more prominent examination depth to evaluate and study the relationship between deep and shallow aquifers. Acknowledgements The authors of this chapter would like to acknowledge the participation of all authors who contributed in this volume. Also, great thanks and appreciation are due to editors of the Springer Water book edition for their continuous support and help whenever needed. All thanks are to the Springer’s team for their great effort to produce the volume with the highest possible quality. We also thank the referees who made precious comments to the chapters Erina Iwasaki was supported by MEXT/JSPS KAKENHI Grant Number JP17H16026 “Development of the sustainable underground water use in the water-scarce societies in North Africa. Abdelazim Negm acknowledges the partial support of the Science, Technology and Innovation Fund Association (STIFA) of Egypt in the framework of the grant no. 30771 for the project via the Newton-Mosharafa funding scheme call no. 4.”

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