Groundwater properties and potentialities in the Precambrian rocks, Hafafit area, Southeastern Desert, Egypt

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THÈSE

Pour l'obtention du grade de

DOCTEUR DE L'UNIVERSITÉ DE POITIERS UFR des sciences fondamentales et appliquées

Institut de chimie des milieux et matériaux de Poitiers - IC2MP (Diplôme National - Arrêté du 7 août 2006)

École doctorale : Sciences pour l'environnement - Gay Lussac (La Rochelle) Secteur de recherche : Terres solides et enveloppe superficielle

Présentée par :

Ashraf Ismail Embaby Ahmed

Groundwater properties and potentialities in the Precambrian rocks, Hafafit area, Southeastern Desert, Egypt

Directeur(s) de Thèse :

Moumtaz Razack, Gilles Porel, Mathieu Le Coz Soutenue le 15 décembre 2015 devant le jury

Jury :

Président Christian Leduc Directeur de recherche, IRD, Montpellier

Rapporteur Pierre Genthon Directeur de recherche IRD, Hydrosciences, Montpellier

Rapporteur Philippe Le Coustumer Maître de conférences, INPB, Université de Bordeaux

Membre Moumtaz Razack Professeur, Université de Poitiers

Membre Gilles Porel Maître de conférences, IC2MP, Université de Poitiers

Membre Mathieu Le Coz Maître de conférences, Université de Poitiers

Pour citer cette thèse :

Ashraf Ismail Embaby Ahmed. Groundwater properties and potentialities in the Precambrian rocks, Hafafit area,

Southeastern Desert, Egypt [En ligne]. Thèse Terres solides et enveloppe superficielle. Poitiers : Université de

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THESE

Pour l’obtention du Grade de

DOCTEUR DE L’UNIVERSITE DE POITIERS

UFR des Sciences Fondamentales et Appliquées

(Diplôme National - Arrêté du 7 août 2006)

Ecole Doctorale : Sciences pour l’Environnement - Gay Lussac

Secteur de Recherche : Géosciences - Terre solide et enveloppes

superficielles

Présentée par :

Ashraf Ismail Embaby AHMED

*******************************************************************

Groundwater properties and potentialities in the

Precambrian rocks, Hafafit area, Southeastern

Desert, Egypt

************************************************************** Directeur de thèse: Moumtaz RAZACK

Co directeurs: Gilles POREL et Mathieu LE COZ ***********************************************

Soutenue le 15 Décembre 2015 devant la Commission d’Examen

Membres du jury

Rapporteurs:

Pierre GENTHON Directeur de Recherches, IRD Montpellier

Philippe LE COUSTUMER Maître de Conférences, HDR, Université de . Bordeaux

Examinateurs:

Christian LEDUC Directeur de Recherches, IRD Montpellier

Gilles POREL Maître de Conférences, Université de Poitiers

Mathieu LE COZ Maître de Conférences, Université de Poitiers

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List of Tables

Tab.1.2:Temperature statistics. ... - 8 -

Tab.1.3: Rainfall statistics. ... - 9 -

Tab.1.4: Emberger's aridity scale (Emberger, 1955). ... - 10 -

Tab.1.5: Aridity indices of different climatic regions (Pahari and Murai, 1995) ... - 10 -

Tab.1.6: Degree of aridity in the studied area based on Murai and Hunda (1991). ... - 11 -

Tab.1.7: Sites of the collected Red Sea water samples (MRC, 2005). ... - 12 -

Tab.1.8: Data of chemical analysis of Red Sea water (mg/l), (MRC, 2005). ... - 12 -

Tab.1.9: The main litho-stratigraphic succession in the study area (Geological Survey of Egypt, 1997). ... - 24 -

Tab.2.1: Classification of Precambrian rocks in Wadi Hafafit. ... - 30 -

Tab.3.1: The history of remote sensing from (1960-2012). ... - 54 -

Tab.3.2: Bands wavelength, ground resolution and band identification for landsat image . ... - 57 -

Tab.3.3: Common band combination in RGB composition for Landsat 7, Landsat 5 compared to Landsat 8. - 58 - Tab.3.4: Description of Modeling Functions Available for Radiometric Enhancement. ... - 61 -

Tab.3.5: Minimum and maximum value for each band (Russ et al. 1999). ... - 61 -

Tab.3.6: Description of Modeling Functions Available for Enhancement, Russ et al. (1999). ... - 63 -

Tab.3.7: Description of Modeling Functions Available for Enhancement, Russ et al. (1999). ... - 64 -

Tab.3.8: Comparing between (RGB) and (HSl), (Levin, 1999). ... - 65 -

Tab.3.9: Comparison between the Visual and the Automatic (Digital) lineament extraction methods. ... 84

Tab.4.1: Morphometric Parameters formula. ... 96

Tab.4.2: Classification of Watershed slopes according to elongation ratio (Horton, 1932)... 100

Tab.4.3: Drainage Texture classification (Smith, 1950). ... 102

Tab.4.4: Snyder's synthetic unit hydrograph parameters. ... 106

Tab.4.5: Correlation coefficientandstatistics of Snyder's unit hydrograph parameters. ... 107

Tab.4.6: Yield of bore-wells in crystalline rocks (Ahmed et al. 2008). ... 119

Tab.4.7: Wells Yield in crystalline rocks within the Nile River Basin (MacAlister et al., 2012). ... 119

Tab.4.8: The hydraulic parameters in sedimentary and Precambrian aquifers (Ahmed, 2010). ... 124

Tab.4.9: Analysis of data from pumping test with Theis (1935) recovery method (Saleh, 1993)... 124

Tab.4.10: The hydraulic parameters of Nubian sandstone in wadi Abadi, Eastern Desert of Egypt ... 124

Tab.4.11: Location and coordinates of monitoring wells subjected to geophysical logging data and Location and coordinates of geophysical survey stations. ... 127

Tab.5.1: Summary statistics of groundwater physical and chemical parameters ... 138

Tab.5.2: Summary statistics of groundwater physical and chemical parameters ... 139

Tab.5.3: Correlation matrix between chemical variables ... 139

Tab.5.4: Electrical conductivity classification (Mandel and Shiftan, 1981) ... 140

Tab.5.5: Total Dissolved Solids classification (Hem, 1985) ... 140

Tab.5.6: Classification of water according to its bicarbonate content (Scholler, 1956)... 146

Tab.5.7: Ion dominance and water type of groundwater samples in the study area ... 153

Tab.5.8: Classification according to Bazeilevich and Pankova (1968) nomenclature ... 154

Tab.5.9: Hardness classification according to Peavy et al. (1986) ... 158

Tab.5.10: Classification of water according to degree of hardness (Alekin, 1970). ... 158

Tab. 5.11: Total hardness based on Mitra et al. (2007) ... 159

Tab.5.12: Hydrochemical coefficients of groundwater salinization. ... 161

Tab.5.13: Hydrochemical coefficients of weathering process. ... 167

Tab.5.14: Hydrochemical coefficients of ion exchange process. ... 167

Tab.5.15: Saturation indices of groundwater samples in study area. ... - 174 -

Tab.5.16: Summary statistics of cluster groups, ion concentrations and TDS are in mg/l. ... - 177 -

Tab.5.17: Eignevalues and explained variance of PCA. ... - 179 -

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Tab.5.19: Groundwater suitability for drinking and domestic uses based on TDS. ... - 182 -

Tab.5.20: Maximum permissible limits according to (WHO, 1996 and EHCW, 2007). ... - 182 -

Tab.5.21: International standards for drinking water by the (WHO, 1984&2006). ... - 183 -

Tab.5.22: The upper limits of total dissolved solids for livestock . ... - 184 -

Tab.5.23: The guide lines of using saline water for livestock and poultry. ... - 184 -

Tab.5.24: Type of water based on (Na %) parameter ... - 186 -

Tab.5.25: Type of water in the study area based on (Na %) parameter. ... - 186 -

Tab.5.26: Groundwater classification based on S.A.R. ... - 188 -

Tab.5.27: Suitability of groundwater for irrigation based on EC and SAR for groundwater samples. ... - 189 -

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List of Figures

Fig.i: Water Scarcity in Egypt, (modified after Wagdey, 2008). ... - 2 -

Fig.ii: Location map of Egypt regions and study area. ... - 3 -

Fig.1.1: Location of meteorological stations in Southeastern Desert of Egypt. ... - 6 -

Fig.1.2: The climate districts of Egypt (INECO, 2009)... - 8 -

Fig.1.3:Climatic parameters of El-Quseir and Ras-Banas Stations. ... - 11 -

Fig.1.4: Simplified geological map of the study area (modified after the geological map of Aswan, 1979). ... - 13 -

Fig.1.5: Lithostratigraphic succession of coastal sediments in the area between Marsa Alam – Ras Banas, Red Sea Coast. ... - 22 -

Fig.1.6:Field relations, observations and petrography of coastal plain sediments. ... - 23 -

Fig.1.7: Simplified structural map of the study area (modified after the geological map of Aswan, 1979). .... - 26 -

Fig.1.8: Geological cross section of the study area... - 26 -

Fig.2.1: A) Location map of the study area ... - 31 -

Fig.2.2: New detailed simplified lithological map of Migif-Hafafit obtained from Landsat ETM-8 and field inspection. ... - 32 -

Fig.2.3: Field relations and observations of migmatites ... - 33 -

Fig.2.4: Field relations and observations of gneissic granitoids ... - 35 -

Fig.2.5: Petrography of the main facies of gneissic granitoids ... - 36 -

Fig.2.6: Field relations and observations of biotite and hornblende gneisses ... - 38 -

Fig.2.7: Petrography of biotite and hornblende gneisses ... - 39 -

Fig.2.8: Field relations and observations of psammitic gneisses ... - 40 -

Fig.2.9: Field relations and oservation of amphibolites: ... - 41 -

Fig.2.10: Petrography of amphibolites ... - 42 -

Fig.2.11: Petrography of pelitic schist... - 43 -

Fig.2.12: Petrography of mylonitized rocks ... - 45 -

Fig.2.13: Field relations of serpentinite rocks ... - 47 -

Fig.2.14:Petrography of foliated metagabbros, metavolcanics and late granitoids ... - 49 -

Fig.2.15: Field relations and observations of late granitoids and dykes ... - 51 -

Fig.3.1: The electromagnetic (EM) spectrums chart (Jensen, 1996)... - 55 -

Fig.3.2: Passive and Active Sensors (Sanderson, 2010). ... - 56 -

Fig.3.3: Bandpasses for Landsat 8 OLI and TIRS sensor, compared to Landsat 7 ETM+ Sensor (USGS, 2014). - 57 - Fig.3.4: The Landsat ETM-8 FCC (7,5,3) in RGB for the Region of interest. ... - 68 -

Fig.3.5: A) Landsat ETM-8 FCC (4, 3, 2) in RGB;B) Landsat ETM-8 FCC (7, 5, 3) in RGB. ... - 69 -

Fig.3.6: A) Landsat ETM-8 FCC (6,5, 7) in RGB;B) Landsat ETM-8 FCC (1, 6, 5) in RGB. ... - 70 -

Fig.3.7: A) Landsat ETM-8 RCC (6/2, 6/7, 6/5*4/5) in RGB; B) Landsat ETM-8 RCC (6/7, 5/6, 4/2) in RGB. ... - 73 -

Fig.3.8: A) Landsat ETM-8 RCC (5/7, 5/1, 5/4*3/4) in RGB; B) Landsat ETM-8 RCC (6/4, 4/2, 7/6) in RGB. ... - 74 -

Fig.3.9: A) Landsat ETM-8 PCA (PC1, PC2, PC5) in RGB;B) Landsat ETM-8 PCA (PC1, PC4, PC2) in RGB. ... - 76 -

Fig.3.10: A) Landsat ETM-8 PCA (PC2, PC4, PC1) in RGB. B) Landsat ETM-8 PCA (PC3, PC4, PC1) in RGB. ... - 77 -

Fig.3.11: A) Landsat ETM-8 unsupervised classification;B) Landsat ETM-8 post classification of supervised classification. ... - 80 -

Fig.3.12: Manual lineaments extraction of Landsat ETM-8 (PC1); A) Lineaments map;B) lineaments length (L %); C) Lineaments frequency (N %). ... 85

Fig.3.13: Automatic lineaments extraction of Landsat ETM-8 (Band 1); A) Lineaments map B) lineaments length (L %); C) Lineaments frequency (N %). ... 86

Fig.3.14: A) Manual lineament density map of (PC1); B) Automatic lineaments density map of Band1. ... 88

Fig.3.15: A) Automatic lineaments distribution of Band 1 in lithological units; B) Automatic lineaments intersection map of Band 1. ... 89

Fig.3.16: Feasible zones for groundwater potentiality. ... 90

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Fig.4.2: Catchments in the study area ... 97

Fig.4.3: The main sub-basins of the Nile River system and their contribution to the Nile ... 109

Fig.4.4: Comparison between Egyptian Water Resources in 2010 and 2025 (modefied after Zaghloul et al., 2012). ... 111

Fig.4.5: Egyptian individual average share of water during the period from 1947 to 2050 (Zaghloul et al., 2012). ... 112

Fig.4.6: Average annual precipitation ... 113

Fig.4.7: Major aquifer systems in Egypt (RIGW, 1988 and RIGW, 1993). ... 114

Fig.4.8: Schematic cross-section extending from areas west of the Nile ... 114

Fig.4.9: Sketch diagram depicts the aquifer types and flow directions ... 115

Fig.4.10: The stratiform conceptual modelof structure and hydrogeological properties of hard rock aquifers 118 Fig.4.11: Detailed hydrogeological units in the study area (from Geological Map of Aswan, 1979). ... 120

Fig.4.12: Piezometric map of the study area... 123

Fig.4.13: Location of borehole logs and geophysical stations ... 128

Fig.4.14: Stratigraphic correlation of boreholes derived from well logging. ... 129

Fig.4.15: Location of hydrogeological cross sections, logs and geophysical stations. ... 131

Fig.4.16: Vertical sections in the study area trending West (A) - East (B). ... 132

Fig.4.17: Vertical sections in the study area trending SE (C)- NW (D)... 133

Fig.4.18: Vertical sections in the study area trending SW (E)- NE (F). ... 134

Fig.4.19: Hydrogeological cross section along study area trending West (A) –East (B). ... 135

Fig.4.20: Hydrogeological cross section along study area trending SE (C)- NW (D). ... 135

Fig.4.21: Hydrogeological cross section along study area trending SW (E)- NE (F). ... 136

Fig.5.1: Spatial distribution of pH, EC and TDS map in mg/l. ... 141

Fig.5.2: Spatial distribution of cations in mg/l... 145

Fig.5.3: Spatial distribution of anions in mg/l. ... 149

Fig.5.4: Spatial distribution of minor elements in ppb. ... 152

Fig.5.5A: Schoeller diagrams Metavolcanic and basic-ultrabasic aquifers ... 155

Fig.5.5B: Schoeller diagrams of granitoids aquifer. ... 155

Fig.5.5C: Schoeller diagrams of Meta-sediments, Quaternary and Miocene aquifers. ... 156

Fig.5.6: Piper Diagram of hydrochemical data. ... 156

Fig.5.7:A)Binary diagram of Na/Cl versus Cl [meq/l-];B) Binary diagram of Na [mmole/l] versus Cl [mmole/l]; C) Spatial distribution of Na/Cl; D) Spatial distribution of [(rNa-rCl)/rSO4]. ... 162

Fig.5.8: A) Spatial distribution of r[(rNa++rK+)/Cl-]; B) Spatial distribution of rCl-/rHCO3-. ... 163

Fig.5.9: A) Scatter diagram of TDS vs. rNa/rCl; B) Plot of Mg/Ca vs. Na/Ca; C, D) Spatial distribution of rSO4--/rCl -and of Mg2+/Ca2+ ratios. ... 168

Fig.5.10: Gibbs diagram TDS [mg/l] vs. (Cl/Cl+HCO3) [ppm]... 169

Fig.5.11A, B) Plot of Ca2+ vs. HCO3 and of Ca2+ vs. Mg2+ ... 170

Fig.5.12a: Dendrogram of the hydrochemical variables. ... - 177 -

Fig.5.12b: Dendrogram of the hydrochemicalcases. ... - 178 -

Fig.5.13: Scree Plot of Principal Components Analysis. ... - 179 -

Fig.5.14: Plot of the variables on PC1 vs. PC2 ... - 180 -

Fig.5.15: Plot of the groundwater samples on PC1 vs. PC2... - 181 -

Fig.5.16: A) Pie chart of groundwater classification based on salinity and suitability for drinking ... - 183 -

Fig.5.17: Pie chart of groundwater suitability for livestock and poultry. ... - 185 -

Fig.5.18: A) Pie chart of suitability for irrigation based on TDS and sodium ion percent (Na%)... - 186 -

Fig.5.19:A) Spatial distribution of sodium ion percent (Na%); B) Wicox, s Classification for evaluation of water irrigation. ... - 187 -

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This dissertation is dedicated

to my father, mother, sisters

and brothers.

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ACKNOWLEDGMENT

All the praise is to Almighty ALLAH who granted me believe and patience to complete this work. I wish to extend my deepest appreciation and gratefulness to the following individuals and institutions for their help in this research.

I wish to express my deepest appreciation and gratitude thanks to Prof. Dr. Moumtaz RAZACK, Professor of faculty of science, Poitiers University, France for supervising and planning the whole work and for his great efforts, guidance, encouragement, valuable discussions, constructive suggestionsand careful review of the draft of this thesis. His door was always open for any question and regular discussions.

I am grateful to Dr. Gilles POREL, Associate professor of faculty of science, Poitiers University, France for his guidance and supervision. I would like to express my deepest appreciation to Dr. Mathieu LECOZ, Associate professorof faculty of science, Poitiers University, France for great discussions, kind cooperation, support during the progress of this work and supervision.

I would like also to thank the members of the jury for having accepted to assess my thesis. My deepest thanks and gratitude to Prof. Dr. Christian LE DUC, Research Director. IRD, Montpellier, France, President of the jury for his interest in my work and for having accepted tobe president of the jury and for rigorous reading, constructive criticism valuable remarks and careful review of the manuscript.

I would particularly like to express my deepest gratitudeto Prof.Dr. Pierre GENTHON, Research Director, IRD, Montpellier, France, member of the jury his particularly rigorous reading, constructive suggestions and time spent in writing the report.Many thanks would be goes to Ass.Prof. Philippe LE COUSTUMER, Associate professor, INP (ENSEGID), Bordeaux University, France, member of the jury his reading, positive suggestions and time spent in writing the report.

A great deep impassioned thank goes to Dr. Claude FONTAINE, Research engineer, Poitiers university, France for valuable discussion and suggestions,assistance in facilitating laboratory workand his contribution in writing abstract in French version. A lot of thanks to Marie-France HUBERT, secretary of hydrogeologydepartment, University of Poitiers for her help in administrative matters and cooperation.

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I would passionately like to depict impassioned and appreciation to the cultural affairs and mission sector, Ministry of Higher Educationin Egypt for the munificent funding me during more than three years and funding the research that helpto carry this research out. Also, I would like to thank the IC2MP institution, Poitiers University, France for funding the work.In addition, I would like to thank the Cultural Office members, Embassyof the Arab Republic of Egyptin France for support and assistance during y stay i France.

Finally, I would also like to express my genuine thanks to my father for her moral support. He believed in me and stood always behind me encouraging and pushing forward to bring this work in its final form. Hearty and warm feeling and passionate thank goes to my mother, brothers, sisters and faithful friends for their support, encourage and help.

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Propriétés et potentialités du système aquifère Précambrien de la région de Hafafit, Désert du Sud-Est, Egypte.

Résumé étendu

Cette thèse s’inscrit dans le cadre des travaux de recherche de nouvelles ressources en eau en Egypte orientale. Elle est plus spécifiquement axée sur la région du désert Sud-Oriental de l'Egypte, zone à fort développement économique. Plus spécifiquement, le présent travail porte sur les propriétés et les potentialités en eau souterraine du système aquifère précambrien dans la région de Hafafit. En effet, dans cette région, les eaux souterraines représentent la ressource la plus importante pour la boisson et les usages domestiques, industriels, et

agricoles. La répartition spatiale des roches réservoirs, ainsi que leur structure ont d’abord été

déterminées afin de comprendre la distribution des aquifères associés et les écoulements préférentiels des eaux souterraines. La méthodologie utilisée est le couplage du travail de terrain pour identifier les roches à l'affleurement et le traitement des images Landsat-8 en utilisant les techniques de télédétection. Cette approche a permis une cartographie géologique détaillée de la région de Hafafit et aussi de dessiner la carte de densité des linéaments et leur orientation. Les résultats ont permis d’identifier les zones potentiellement aquifères.

La deuxième étape a consisté amener une étude pétrographique afin de déterminer la minéralogie et, par conséquent, les éléments chimiques impliqués dans les interactions

eaux-roches. L’objectif est de comprendre les processus physico-chimiques à l’origine de la

minéralisation des eaux souterraines des aquifères Précambriens. Enfin, à l’aide de

l’ensemble des données climatiques, géologiques, hydrologiques, hydrogéologiques et

chimiques, l’élaboration d’un modèle conceptuel du système aquifère du Précambrien de la

zone de Hafafit a été tentée afin d’expliquer ses propriétés physico-chimiques et ses potentialités.

Le désert Sud-Oriental de l'Égypte est limité par les longitudes 33°50' 00" - 35°45' 00" E et les latitudes 24° 00' 00"- 25°15' 00"N et couvre une superficie d'environ17.290 km². Ainsi, il forme une longue banded 'environ150-200 km de large, bordée à l'Ouest parle Nil et à l'Est parla Mer Rouge. La zone étudiée est située dans la partie sud de cette bande et peut être définie par un quadrilatère dont les sommets sont, au Nord, les villes d'Idfu et El-Qusier et ceux d'Assouan et Ras Banas au Sud. Pour la zone étudiée, des histogrammes des variations saisonnières de température et de précipitation ont été établis sur les cinq dernières décennies en utilisant les relevés météorologiques historiques de deux stations situées respectivement àl'Ouest (Assouan sur le Nil) et au Nord (El Qusier sur la Mer Rouge). Les données de la

nouvelle station implantée à l’Est (Marsa Alam sur la Mer Rouge) ne couvrent que la

chronique des 6 dernières années. Malheureusement, aucune station n’a été implantée dans la

partie montagne use de la région étudiée.

Ces histogrammes montrent que, dans la région de Hafafit, la température varie de 22 à 36°C avec une moyenne de 28°C. L'effet de la température est renforcé par l’ensoleillement relatif annuel moyen, compris entre 80% et 106% entre les deux saisons. L'humidité relative annuelle varie entre 32% et 60% de l'hiver à l'été. Les précipitations annuelles varient de 0 à 117 mm/an dans l'Ouest (Assouan) et de 0 à 195 mm/an dans le Nord (El Qusier) avec une

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moyenne générale de 50 mm/an pour toute la région. Ce pendant de longues périodes de sécheresse peuvent succéder à certains événements pluviométriques intenses (souvent 60

mm.h-1). Un autre critère important du climat local est le vent qui souffle régulièrement avec

une vitesse moyenne élevée à près de 20 km/h. Par conséquent, l'évaporation potentielle peut atteindre 10 mm/ jour. Toutes ces conditions témoignent du degré élevé de l'aridité de la région de Hafafit et du faible potentiel de recharge des aquifères par les apports pluviométriques. La région de Hafafit est caractérisée par une chaîne faite de collines de moyenne à basse altitude (500 à 800 m), constituées de roches précambriennes, et bordée par des affleurements réduits de roches sédimentaires.

A l’Ouest, vers le Nil, la séquence sédimentaire est composée de haut en bas par des alluvions quaternaires, des schistes éocènes détritiques et marins, des niveaux pliocènes décrie et de marne. Cette séquence recouvre les formations du Crétacé supérieur (carbonates, phosphates et roches détritiques) et les grès Nubiens du Crétacé moyen qui forment le socle

sédimentaire régional. A l’Est, près de la Mer Rouge, la couverture sédimentaire de la plaine

côtière est épaisse, datée du Miocène au Quaternaire, caractérisée par des dépôts marins et des formations coralliennes.

La partie centrale de la chaîne est formée de roches d’âge Précambrien. Sur la base de leur

nature pétrographique et de leur âge respectifs on distingue régionalement deux grands

ensembles nommés Unités Infra- et Supra-structurale. L’Unité Infrastructurale (700-900 M.a)

est constituée de roches de croûte continentale dont la séquence commune est

migmatites-granitoïdes gneissiques-gneiss Psammétique, gneiss à biotite-amphibolites-schistes

pélitiques. Selon le degré du métamorphisme régional, certaines de ces roches développent une schistosité et sont plus ou moins intensivement pliées. Deux aquifères sont liés à cet

ensemble, l’un associé aux méta-sédiments et l'autre aux formations granitiques. L’Unité

Suprastructurale (âge) correspond à des roches basiques et ultrabasiques de croûte océanique obductée. Cette séquence est formée de serpentinites (plus ou moins altérés, comme indiqué

par la présence d’antigorite, de carbonates et de talc), de métagabbro, de métavolcanites.

Deux aquifères ont été identifiés en relation avec les roches métavolcaniques et les roches

basiques-ultrabasiques. Enfin, une grande partie de toutes ces roches a été recoupée

tardivement (720-835 M.a) par les intrusions de granitoïdes et par de nombreux dykes et veines de granite, dolérite, aplite et quartz. Les zones très fracturées sont des zones préférentielles d’écoulement pour les eaux souterraines.

La technique de télédétection est un outil d’analyse 2D très important et très puissant pour la cartographie des roches et l'extraction des linéaments. Les données du satellite Landsat-8 ont

été utilisées pour l’étude de la zone de Hafafit sur une superficie de 312 km2_{. Les linéaments}

se permettent de déterminer les zones d’écoulement préférentiel de l'eau souterraine et

servent de base pour l'exploration et la prospection des aquifères fracturés. Le traitement des

images Landsat-8 a permis d’identifier les zones potentielles d’écoulement des eaux

souterraines. Les linéaments possèdent deux orientations principales NW-SE et NE-SW qui reflètent à l'évolution tectonique dans Sud-Est de l'Egypte. Ces zones ont sur tout été

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considérées comme des sites appropriés pour l'exploration géophysique et l’implantation des

futurs forages.

L'analyse morphométrique est une étude incontournable à la compréhension du comportement hydrologique et géomorphologique des bassins versants. La méthode synthétique de l'hydrogramme unitaire de Snyder dans les bassins versants non jaugés a permis de calculer le débit de pointe et le temps de base dans ces bassins versants sur la base des caractéristiques physiques et des coefficients constants.

La diagraphie géophysique a permis une visualisation 3D de la structure des roches aquifères par corrélation stratigraphique entre les forages. A grande échelle, la structure géologique de la région d’Hafafit peut être décrite par l’empilement de trois couches principalement. La première couche correspond aux dépôts quaternaires de wadi (épaisseur comprise entre 15 à 60 m), déposés directement sur le socle précambrien, et aux récifs coralliens dans la zone côtière. La deuxième couche englobe les roches fracturées et altérées, argiles et calcaires (épaisseur comprise entre 20 - 100 m). Enfin, la troisième couche, est assimilable aux roches précambriennes massives du socle (épaisseur entre 40 à 250 m).

Sur la base de ce qui précède, les formations aquifères peuvent regroupés en deux catégories : les aquifères côtiers de la Mer Rouge (aquifères du Mio-Quaternaire), et les aquifères fracturés du Précambrien. La carte piézométrique de ces aquifères montrent que les isopièzes s’étagent de 0,5 à 590,0 m et définissent des zones de recharge en zone d’altitude. Par ailleurs, les écoulements des eaux souterraines se font selon deux directions principales à

savoir, vers l'Esten direction de la mer Rouge et vers l’Ouest en direction du Nil. Enfin, la

carte piézométrique montre une ligne de partage des eaux souterraines en bonne coïncidence avec la ligne de crête topographique.

La caractérisation pétrographique des roches aquifères permet de mieux comprendre la chimie des eaux souterraines. Les roches de l'Unité Infrastructurale sont essentiellement des roches silico-alumineuses composées de quartz, plagioclase, feldspath potassique et micas (biotite et muscovite). Par conséquent, dans ce domaine, la chimie des eaux souterraines résultant des interactions eau-roches possédera une signature Si, Al, Na, Ca et K. Ceci apparaît nettement dans les aquifères méta-sédimentaires et l'aquifère granitique. En

revanche, l'Unité Suprastructurale est un ensemble de roches basiques – ultrabasiques dont

les constituants minéraux sont essentiellement d'olivine, de pyroxènes et de magnétite partiellement altérés en antigorite, talc et carbonates (calcite et magnésite). Aussi, les eaux des aquifères de cette Unité sont-elles largement enrichies en Si, Mg, Ca, HCO3 et Fe. Par

ailleurs, ces roches étant riches en sulfures (pyrite), leur altération est à l’origine des teneurs

importantes en sulfates. Cette signature est propre aux eaux de l’aquifère méta-volcanique et

de l’aquifère basique-ultrabasique.

Les propriétés physico-chimiques de l'eau souterraine sont représentées parle pH, la conductivité (CE) et la salinité. La valeur de pH est faible dans la partie orientale et élevée dans la partie Ouest de la zone d'étude. Parallèlement, la valeur de CE et la salinité augmentent vers la côte de la Mer Rouge et diminuent dans la partie ouest de la zone.

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L’évolution de ces paramètres au niveau des aquifères côtiers met en évidence l'intrusion de l’eau de mer dans les nappes. Les ions majeurs sont Ca2+_{, Mg}2+_{, Na}+_{, K}+_{, Cl}-_,Br-_{, SO}

42-, PO4

2-, CO32- et HCO3-, et constituent près de 98% de la minéralisation totale des eaux souterraines.

La salinité (TDS) et la conductivité électrique (CE) sont fortement corrélées entre eux et possèdent une corrélation positive avec Ca, Mg, Na, Ket Cl. A partir de ces données et des diagrammes de discrimination les eaux souterraines peuvent être classées en trois catégories

:1) Cl-Na dominants dans les aquifères granitiques, méta-volcaniques, basiques

-ultrabasiques, méta-sédimentaires et dans les aquifères Quaternaire-Miocène; 2) Cl-Ca

dominants dans les aquifères granitiques et basiques-ultrabasiques; 3) SO4 dominant dans les

aquifères méta-volcaniques, granitiques et méta-sédimentaires. La présence notable de Na

caractérise les aquifère granitiques, méta-volcaniques et méta-sédimentaires. Les indices de saturation des minéraux montrent que la calcite et la dolomite ont atteint l'équilibre dans les

aquifères basiques-ultrabasiques, mais sont en sursaturation dans d'autres aquifères. Les

minéraux évaporitiques montrent des degrés de saturation plus faibles que les minéraux

carbonatés ; ce qui semble indiquer que dans le domaine d’étude l’halite (et donc l’eau de

mer) n’est pas la source principale de Na+_{et Cl}-_.

Dans la région d’Hafafit les processus hydro-chimiques responsables de la minéralisation des eaux sont tout d’abord ’altération des roches aquifères et les échanges ioniques eau-roche encaissant. A ces processus se surimpose l’action de l’évaporation très importante comme l’étude des données climatiques l’a montré. Enfin, à proximité de la Mer Rouge les phénomènes de salinisation peuvent se révéler prépondérants.

Les variations du degré de salinité montrent que la plupart des eaux souterraines des aquifères

précambriens de la partie ouest de la région sont d’origine météorique, tandis que les eaux

des aquifères côtiers de la partie orientale possèdent une forte contribution d’eaux d’origine

marine. Toute fois, qu’elles proviennent des aquifères précambriens ou côtiers toutes ces

eaux possèdent une signature partielle attribuable à l’altération des silicates des roches encaissantes. Par ailleurs, les diagrammes de Gibbs montrent également que toutes ces eaux souterraines ont été soumises au processus d'évaporation. Sur la base des critères de l'OMS (2006), la classification des eaux souterraines en fonction de leur qualité (boisson et usages domestiques) montre que très peu de forages (30%) sont de bonne qualité. De même, en utilisant le critère TDS, il apparaît que seuls 29% des eaux analysées sont aptes à être utilisées pour l’irrigation.

Perspectives et recommandations

Bien que cette recherche ait apporté une contribution importante à la compréhension des ressources en eau du désert sud-oriental en Egypte, les connaissances préliminaires acquises restent encore insuffisantes pour développer une véritable gestion durable de ces ressources. Aussi, dans les travaux futurs, les efforts devront se concentrer sur les points suivants:

Meilleure estimation du bilan en eau de la région. Le bilan eau de la région est encore insuffisamment connu. Les études sur les estimations du bilan de l'eau, mettant en œuvre plusieurs méthodes et des systèmes de mesures in situ devront être encouragées.

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xvii

Ainsi, la densité des stations météorologiques, dont certains domaines sont

entièrement dépourvus, devra être accrue afin d’avoir de disposer des données

climatiques régionales nécessaires à l’établissement des bilans hydriques

Parallèlement il faudrait implanter un réseau de piézomètres de surveillance des eaux souterraines. Ce qui, à l'heure actuelle, fait totalement défaut. Sa mise en œuvre permettrait l'acquisition de données sur les fluctuations piézométriques, d’établir des relations précipitations-piézométrie, et d’estimer la recharge des aquifères.

D’autre part, il est nécessaire de réaliser une estimation des paramètres hydrodynamiques. Les données relatives aux paramètres hydrauliques importants tels que la conductivité hydraulique, la transmissivité, l’emmagasinement sont très rares et ne couvrent pas l'ensemble de la région. Ces paramètres ont un grand impact sur la circulation des eaux souterraines. Ainsi, il est fortement recommandé d'augmenter de manière significative les essais hydrauliques.

Les méthodes isotopiques peuvent également être mises en œuvre. De manière complémentaire, elles permettront de mieux comprendre et quantifier le cycle de l'eau dans le désert oriental.

Enfin, une recommandation importante concerne les bases de données. Actuellement, l'accès aux données est très difficile et prend du temps, en raison

de leur parcellisation et d’une gestion non unifiée. Aussi, un travail de collecte

et de centralisation de toutes les données déjà disponibles liées à l'eau est

fortement recommandé. Seul l’établissement de telles bases de données

permettra à terme de réaliser une modélisation 3D des systèmes aquifères du Désert oriental.

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Introduction

1. Background and Concept

Water shortage is a major problem worldwide as a result of dramatic growth of population and industry as well as climate change and water pollution. With a rapidly growing population, fast urbanization, rising general living standards andin the same time, an agricultural policy that must increase food production, Egypt is facing one of its water needs crisis (Engelman and Le Roy, 1993). The World Bank describes Egypt system as being "Under Water Stress". Therefore, it is important to improve planning and to identify a proper management procedure for the available water resources in Egypt (Diab and Rizk, 1992).On average, the rate of population growth is 1.5 million per year (CAMPS, 2009). The population has tripled in just 50 years from 19 million (1947) to about 83.5 million (2012) of whom about 99% are concentrated in the Nile Valley and Delta and will be 100 million by the year 2025 (Abdel-Lateef et al., 2011).

The last fifty years in Egypt the population has increased by more than three times, Meanwhile, the available renewable water resources remained the same (Wagdy, 2008). Consequently, Egypt is facing a very significant imbalance between water demand and the available resource. The annual per capita share of renewable water resources (mainly provided by the Nile) is dramatically reduced from more than 2500 m3 at the year 1950 to less than 900 m3 at the year 2000, and expected to fall to about 500 m3/cap/yr by the year 2050 (Wagdy, 2008), as shown in (Fig.i). The future water policy considers the per capita share of Nile water will drop sharply under all standards of water poverty within the next two decades (Abd El-Moniem, 2005).It is therefore vital to improve planning and to identify a proper management procedure for the available water resources in Egypt (Diab and Rizk, 1992).

From the Nile Valley to the East, fresh water supply is essential and desalination is a feasible option to make up the wide gap between the available capacities and the accelerating demands (Shawky et al. 2012). However, in the Eastern Desert of Egypt, where the water resource-demand gap is very strong (Abd El-Moneim, 2005), the desalination solution is hardly feasible. Eastern Desert consists of 90% desert area, this region covers only 22% of national area, but the tourist presence makes it a major economic zone.

Limited natural fresh water resources in the Eastern Desert of Egypt call for evaluation of

water potential. Nowadays, the total current water resources of Egypt is 70.26 billion m3 and

the strategic development plan of the resource is to reach 79.4 billion m3 by 2017 (Zaghloul

et al., 2012). In this context, exploration of additional drinking and domestic water resources will be necessary in Eastern Desert, Therefore, a precise estimation of hydrogeological potential of Eastern Desert region led to study the water reservoir rocks which are composed of Precambrian rocks essentially.

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- 2 -

Fig.i: Water Scarcity in Egypt, (modified after Wagdey, 2008).

The Precambrian rocks are part of the Arabian Nubian Shield and represent 10% (100,000

km2) of the total outcropped rocks in Egypt (Said, 1990) and especially in the Eastern Desert

area. They are mainly large varieties of Pan-African basement rocks such as migmatites, granitoids, gneiss and metasediments constituting the infra-crustal basement, which overliesby a complex of basic and ultrabasic rocks of Hammamat group associated with Dokhan volcanics and late granitoid bodies. The chemistry of groundwater strongly depends on the water-hosted rocks interaction; consequently a better understanding of petrography and spatial distribution of these rocks is required. On the other hand, these rocks were intensively cut by dykes and deformed by several fault systems and shear zones fractures. These structural elements represent preferential pathways for deep and shallow groundwater and their occurrence and flow. Also, the lineaments play an important role in the groundwater dynamics and it act as indicator to locate the groundwater. Knowledge of the nature and distribution of these structures at different scales of space is crucial for estimating and management of water resource in this area.

2. Geography

Egypt lies in the north-eastern corner of the African continent and only its minor part, i.e. the

Sinai Peninsula, lies within the border of Asia (Fig.2A). The country occupies 1,001,450 km2.

The Egyptian territory is almost rectangular, limited to the North by Mediterranean Sea, to the South by Sudan, to the West by Libya, and to the East by Palestine, Israel, the Gulf of Aquaba and the Red Sea, with a North-South length of around 1,073 km and a West-East width of roughly 1,226 km (Said, 1990). The Red Sea is connected with the Mediterranean Sea by the Suez Canal, which is about 160 km long. The Nile Valley and Delta represent only about 4% of the total surface of the Country, while the largest part is desert (CAPMAS, 2009)

0

500 1000

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Water Scarcity

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with Eastern Desert (22%,) Western Desert (68%), and the Sinai Peninsula (6%), look in (Fig.ii).

3. Location of the study area

The Eastern Desert covers about 220,000 km2_{and is located between the Red Sea and the}

Nile Valley. It extends from latitude 22°N and 29°N or Egypt's borders with Sudan in the South, to the Delta sub-region in the North (Rashed et al., 2006). The Eastern Desert consists of high rugged mountains parallel and at a relatively short distance from the coast. These mountains are flanked to the North and West by jagged sedimentary plateau (Said, 1990). The study area is lying in the southern part of the Eastern Desert of Egypt, stretching east-west between MarsaAlam to Ras Banas on the Red Sea Coast and Baramiaa area in Idfu-Marsa Alam road. The area is limited by longitudes 33050’00” - 350_{45’00”E and latitudes}

24000’00” - 250_{15’00”N covering area about nearly 17,270 km}2_{(Fig.ii). On the point of}

accessibility, the study area can be reached by the main asphaltic roads, Qusier –Marsa Alam

road or Idfu-MarsaAlam road. The roads in the area Marsa Alam–Idfu bounded the area in

the northern part and El-Sheikh El-Shazly road cut the area from North to the South.

Fig.ii: Location map of Egypt regions and study area.

4. Topography

Egypt's landscape separates into high plateaus and low depressions enclose fluvial and littoral plains as shown in (Fig.4.1). These geomorphologic units play an important role in determining the hydrogeological framework of Egypt and natural constraints facing population distribution. The structural plateaus constitute the active and semi-active watershed areas. The low plains can contain productive aquifers and are also, in places, areas of groundwater discharge.The geomorphology assumes an imperative part in detecting the hydrogeological system in Egypt and characteristic requirements confronting population

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distribution. The structural plateaus comprise the dynamic and semi-dynamic watershed territories. The depressions can includeprofitable aquifers and territories of groundwater release.

5. Aim and scope of the thesis

This study aims to evaluate the groundwater availability, quantity and potentiality in the South Eastern Desert as an essential resource in the area. The results will be used for predictions about groundwater presence and the refill of groundwater reservoirs. This type of study fully agrees with the major Egyptian governmental priorities. The geomorphological and hydrogeological characteristics as well as hydrochemical characteristic and evaluation of groundwater for different purposes will be evaluated. This will be accomplished through field measurements, laboratory analysis and interpretations. The aim and scope of the study can be summarized in the following points:

1- _{Delineation of surface lineaments, fractures, joints and faults using remote sensing} techniques;

2- Visual interpretation of Landsat TM images covering the study area concerning

identification, measurements, analysis and interpretation of the drainage and structural lineaments and linear features (faults, fractures, folds and bedding planes…);

3- _{Investigation of the Precambrian rocks, using field observations and petrographic}

studies;

4- _{Delineation, mapping and analysis of the drainage basins in the study area using}

Digital Elevation Model (DEMs);

5- Subsurface studies such as well logging using geophysical methods to study the

availability of water in fractured subsurface rocks;

6- Hydro-chemical studies of water samples and groundwater quality.

6. Methodology

6.1. Field Works

Two field trips including each 15 days were organized in the study area. In June 2013, the field trip was the first campaign to collect rock and water samples and measure in situ the hydrogeological parameters such as total dissolved solids (TDS), temperature (°C) and pH. In June 2014, the second field tripwas focused on geomorphology and drainage basins to verify image interpretation and to investigate minor forms. Also, lithological mapping, final evaluation of hydraulic parameters and water samples collection were undertaken.

6.2. Laboratory works

6.2.1. Petrographical study

The rock samples were collected in different rock units and 100 representative samples were selected for microscopic studies. Eighty thin sections representing the different varieties of rock units were described under polarizing microscope. About 100 photomicrographs were taken to display petrographic features of different rock varieties.

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- 5 - 6.2.2. Analytical techniques

The water samples were collected from different water wells in the study area during two field trips (June, 2013 and 2014). To collect samples we used 500 mL polyethylene bottles (Kartell) equipped of closure system with double caps and the container has been completely filled in order to minimize the exchange with the ambient air. On the field, these bottles were

stored rapidly in ice-box then in refrigerator at 4o_{C temperature. In the laboratory, all samples}

were filtered using 0.1 µm nitrocellulose membrane Millipore filter to eliminate fine particles of solids in suspension. After that, for each sample, one aliquot of 100 mL was acidified with

some drops of HNO3 (Nitric acid) intended to detect major and minor elements by

Inductively Coupled Plasma Mass Spectrometry (ICP-MS), at the University of Pau (France). The other part was analyzed to determine the content in carbonate and bicarbonate. The protocols operated during samples collection are described by Claasen (1982) and Barcelona et al. (1985). The alkalinity and chloride were measured by titration method in Hydrasa laboratory of the Institut des Milieux et Matériaux de Poitiers (IC2MP).The hydrochemical data are given in Appendix 5.1.

6.2.3. Office work

The laboratory works includes the following steps:

1. Bibliography and collection of geological, topographic maps;

2. Remote sensing techniques include enhancement techniques, lineaments extraction, visual interpretation and detection for Landsat images;

3. Computer analysis and interpretation of the mapped lineaments, and linear features; 4. Hydrologic studies using DEMs and interpretation of the drainage basin analysis.

7. Structure of the thesis

The obtained results and discussion are presented within the following chapters: Chapter One: Climate and Geology

Chapter Two: Investigation of the Precambrian Rocks in Wadi Hafafit Chapter Three: Remote Sensing

Chapter Four: Hydrology and Hydrogeology Chapter Five: Hydrochemistry

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Chapter One: Climate and Geology

1.1. Climate

1.1.1. Meteorological data and distribution of stations

The meteorological stations in the Eastern Desert are few relative to the size of the surface area and these stations are mostly distributed along the Red Sea coast and the Nile Valley. Thus, the recorded data from these stations does not reflect the climatic conditions of the inland areas of the Eastern Desert (Abd El-Moniem, 2005).The available climatic data were unequally measured in 4 stations (Tab.1.1 and Fig.1.1). The study area exists in area of large topographic difference; as a result of this difference the climateis quite variable. The available climatic data were collected from the previous published studies, internet and reports. These data include air temperatures, rainfall, relative humidity, relative sunshine, vapor pressure variation, hector-physical pressure variation and wind velocity for many years. These data were collected from the meteorological stations in Aswan, Marsa Alam, El-Quseir and Ras-Banas.

Tab.1.1: Showing location of meteorological stations.

Station Number

Station Name Latitudes Longitudes Elevation

1 Marsa Alam 250 33/ 00// N 340 35/ 00// E 77

2 Aswan (Civ/Mil) 230 57/ 36// N 320 46/ 48// E 194

3 Ras-Banas 230 58/ 12// N 350 28/ 12// E 4

4 El-Quseir 260 07/ 48// N 340 18/ 00// E 11

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1.1.2. Climatic conditions

Egypt occupies in dry tropicaldistrictexclude northern districts belong to moderate warm

zone comparablethe Mediterranean climate.Egypt’s weather describes through hot dry

summer varies from 38°C -43°C with maximum degree reaches 49°C in Eastern desert and western desert, while in the winter it is moderate with restricted precipitation that increases in the littoral regions.Egypt classifies into six climatic regions (Fig.1.2), (INECO, 2009):

 Mediterranean Region: It stretches out along the Mediterranean Sea with a few kilometers to within. The avereage temperature is around 23°C in summer and 14°C in winter. Theannual precipitation ranges from (100-190 mm/year);

 Nile Delta Region: It covers south of Mediterranean region. The avereage temperature ranges from 13°C - 27°C and the annual precipitation varies from 20 to 50 mm/year;

 Sinai Highlands Region: It comprises mountains and plateaus. The climate in this region varies from different parts in Sinai. The temperature is decreases at least 10°C and the precipitation increases;

 Middle Egypt Region: It occurs in the midst of Cairo and Assiut and stretches toward the western fringes of Egypt and Red Sea mountains in the east. The region is charcterises by cold winter and hot summer (30°C). The annual precipitation is (< 10 mm);

 Upper Egypt Region: It stretches from the south of Assiut toward the southern fringes of Egypt. The precipitation is uncommon and the contrast between the temperatures by day and night comes to 18°C or extra in deserts;

 Red Sea Region: The weather is greater cold and rainy, which varies in Red Sea Mountains from neighborhood plains;

The study area represents a part of the arid belt of North Africa. The Eastern Desert is located in the arid and semi-arid belt of Egypt characterized by hot, dry and rainless climate in summer and moderate with rare rainfall in winter, where sporadic rainfall may occur from time to time and accompanied with flash floods. Sometimes an extremely rainless or shortage in rainfall may continue for years, reaching five to six years, this indicating the hot arid climate of the area. Moreover, the area characterizes by hot summer and warm winter and high evaporation intensities and high wind speed value.

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- 8 - Fig.1.2: The climate districts of Egypt (INECO, 2009).

1.1.3. Air temperature (T C0)

In the Aswan station the annual average Maximum Temperature (TM) was 36.4 C0 during the

period 1958-2012, while the annual average Minimum Temperature (Tm) was 19 Co. The

annual average temperature (T) was 26.7 C0. Temperature statistics recorded at

meteorological stations are provided in (Tab.1.2). Tab.1.2:Temperature statistics.

Aswan station (1958-2012)

Marsa Alam station (2006-2012) El-Quseir station (1963-2012) TM (°C) 36.4 29.4 27.9 Tm (°C) 19.0 22.1 26.1 T (°C) 26.7 20.9 24.7

TM: annual average maximum temperature; Tm: annual average minimum temperature;

T: annual average Temperature.

1.1.4. Rainfall (mm/year)

Rainfall in the Eastern Desert is generally less than 35 mm/year and relativehumidity is low (50% in winter, 15% in summer), classifying the area as arid-hyper arid (EMA, 1996).For the investigated watersheds in Eastern Desert, the average annual precipitation, averageannual

runoff, and average annual recharge through transmission losses were found to be:807 x106

m3, 77.8 x 106m3 (9.6% TP), and 171 x 106m3 (21.2% TP), respectively (Milewski et al., 2009).The rainfall is the main form of precipitation in the study area. Precipitation is

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represented by rainfall, snowfall and dewfall (condensation of atmospheric vapor). There are no available records of snowfall and dewfall in the study area.The rainfall is measured by mm/year (Tab.1.3&Fig.1.3).

Tab.1.3: Rainfall statistics.

Aswan station (1958-2012)

Marsa Alam station (2006-2012) El-Quseir station (1963-2012) Annual rainfall (mm/an) 0-117 0.0 0-195 1.1.5. Wind velocity

Wind velocity changes with times and places (Fig.1.3).In Aswan station the maximum recorded monthly mean value was 18.7 km/hour which was recorded during the period (1958-2012), while the minimum value is 7.2 km/hour, which was recorded during the same period.The mean monthly wind velocity during the considered period was nearly 15.5 km/hour.In Marsa-Alam station, the wind velocity changes with times and places. The maximum recorded monthly mean value was 20.3 km/hour, which was recorded in Aswan station during the period (2006-2012), while the minimum value is 16.9 km/hour, which was recorded during the same period.The mean monthly wind velocity during the considered period nearly is 18.9 km/hour.In El-Quseir station the wind velocity changes with times and places. The maximum recorded monthly mean value was 17.9 km/hour which was recorded in Aswan station during the period (1963-2012), while the minimum value is 10.5 km/hour, which was recorded during the same period.The mean monthly wind velocity during the considered period was nearly 14.2 km/hour.

1.1.6. Evaporation and Evapotranspiration rates

The evaporation value is a function of air temperature, relative humidity and wind velocity. Both the surface water and groundwater are subjected directly or indirectly to evaporation and evapotranspiration processes. Direct evaporation can occur from groundwater if its depth is less than the critical depth of evaporation. This depth ranges from 3 to 4.5 m in the study area (Farrag, 1982). Accordingly evaporation from groundwater can take place in most parts of the old cultivated land. The values of evaporation and evapotranspiration are increased during the warmest months and decreased during the coldest one.The intensity of evaporation was 10.1 mm/day during the period (1934-1994) in El-Quseir station, (Mahmoud, 2005). The evapotranspiration is the evaporation from soil and vegetation cover. Many methods are used to determine this rate. Some of these methods are mainly based on the direct measurements of the evapotranspiration rate.The indirect methods are based on empirical equations which depend on the evaluation of some climatic elements. The evapotranspiration rate calcualted is 138 cm/year according to Thornthwaite formula (Farrag, 1982). On the other hand the evapotranspiration rate was determined as 172 cm/year by the use of Penman Nomogram (Farrag, 1991).

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1.1.7. Other climatic parameters

The following climatic parameters (annual relative sunshine, annual vapour pressure variation and annual hecto-physical pressure variation), modified after Attia (1999) are given in Appendix (1).

1.1.8. Degree of aridity

1.1.8.1. Emberger's formula

The degree of aridity is obtained by the application of Emberger's formula (1955), as follows:

Q = 100 R / (u + m) (u-m)

Q: degree of aridity, R: mean annual rainfall (mm), u: mean maximum temperature for the

warmest months and m: mean minimum temperature for the coldest months. According to the (Tab.1.4), the degree of aridity ranges between (0.84-4.85) in the El-Quseir station and between (0.55-2.22) in the Ras Banas station. According to Emberger's scale (1955), the study area lies within the desert conditions (Tab.1.4).

1.1.8.2. Aridity index of Murai and Hunda The aridity index is defined as:

X= P/(10+T)

Where, P: the mean annual precipitation (mm) and T: the mean annual air temperature (Co).

Tab.1.4: Emberger's aridity scale (Emberger, 1955).

Value of Q Climatic conditions

0-20 Desert conditions

20-45 Arid conditions

45-65 Semi-arid conditions

The aridity index based on Murai and Hunda (1991) classification, defines into four cases (Tab.1.5). This index ranges between 0.14) in El-Quseirstation and between (0.03-0.09) in Ras-Banas station. Accordingy, the study area lies within the Arid (Desert) climate (Tab. 1.6).

Tab.1.5: Aridity indices of different climatic regions (Pahari and Murai, 1995)

Index Class

5 Arid Desert

5-10 Semi-arid Semi-desert

10-30 Semi-arid Grass land

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Tab.1.6: Degree of aridity in the studied area based on Murai and Hunda (1991).

Parameters

El-Quseir Station Ras Banas Station (1966-1995) (1999-2006) (1966-1995) (1999-2006) R (P) 43 7.85 29.9 7.95 M 32.9 33.8 38.6 40.52 M 14 14.68 12 13.44 T 24.32 24.95 25.86 27 Degree of Aridity 4.85 0.84 2.22 0.55 Aridity Index 0.143 0.025 0.093 0.024

Fig.1.3:Climatic parameters of El-Quseir and Ras-Banas Stations.

RA SN TS GR FG TN Aswan St. (1958-2012) 0.8 0.1333 0.2666 0.066 0 0 Marsa-Alam St. (2006-2012) 1.2 0.2833 0.8166 0.2666 0 0 El-Quseir St. (1963-2012) 1 0.1611 0.1611 0.1555 0 0 0 0.4 0.8 1.2

Avereage Climatic Parameters

RA: Total days with rain

during the year

SN: Total days with snow

during the year

TS: Total days with

thunderstorm during the year

GR:Total days with hail

during the year

FG: Total days with fog

during the year

T TM Tm PP V Aswan St. (1958-2012) 26.693 31.76 19.0466 4.514 15.057 Marsa-Alam St. (2006-2012) 27.148 31.99 19.412 30.849 13.477 El-Quseir St. (1963-2012) 27.243 33.203 19.7106 18.496 13.492 0 10 20 30

Avereage Climatic Parameters

T: Annual average

temperature

TM: Annual average maximum

temperature

Tm: Annual average minimum

temperature

PP: Total annual precipitation

of rain and/ or snow (mm)

V: Annual average wind speed

Groundwater properties and potentialities in the Precambrian rocks, Hafafit area, Southeastern Desert, Egypt

THÈSE

THESE

Pour l’obtention du Grade de

DOCTEUR DE L’UNIVERSITE DE POITIERS

UFR des Sciences Fondamentales et Appliquées

(Diplôme National - Arrêté du 7 août 2006)

Ecole Doctorale : Sciences pour l’Environnement - Gay Lussac

Secteur de Recherche : Géosciences - Terre solide et enveloppes

superficielles

Présentée par :

Ashraf Ismail Embaby AHMED

Groundwater properties and potentialities in the

Precambrian rocks, Hafafit area, Southeastern

Desert, Egypt

Contents

List of Tables

List of Figures

This dissertation is dedicated

to my father, mother, sisters

and brothers.

Introduction

1. Background and Concept

2. Geography

0

500

1000

1500

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0

20

40

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1950

1970

1990

2010

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2050

R

enew

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M

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Year

Water Scarcity

3. Location of the study area

4. Topography

5. Aim and scope of the thesis

6. Methodology

7. Structure of the thesis

Chapter One: Climate and Geology

1.1. Climate