Stratigraphic landscape analysis: Charting the Holocene movements of the Nile at Karnak through ancient Egyptian time

Geological analysis of 5–10‐m‐long sediment cores in the context of the anthropologically derived materials within them has allowed us to identify ancient landscape features in the Theban area around Luxor, Egypt. From these observations we propose a sequence of island formation and northwestward movement of the Nile from the Middle Kingdom onward in the area of the temple complexes of Karnak. The geoarchaeological techniques used appear to document the Holocene lateral migration and vertical aggradation of the Nile. Our method can be used to test postulated movements and is applicable to sites in river or coastal plains where sediments were being deposited during the occupation of the site. The sediments were sieved to retrieve sherds and numerous other small items (2 mm and larger), which included worked stone fragments, rootlet concretions (rhizocretions), desert polished sand grains, and occasionally beads. The small stone fragments can be correlated with buildings and sherds of known age within the site, while the rhizocretions and desert sand grains indicate environmental conditions prevailing at the time of deposition. © 2008 Wiley Periodicals, Inc.     

Sea-level rise and shoreline retreat of the Nile Delta promontories, Egypt

Studies of the Nile Delta coast have indicated wide values of local subsidence, ranging from 0.4 to 5 mm/yr. Trend analysis of sea-level rise and shoreline retreat at two Nile Delta promontories have been studied. Records from tide gauges at Alexandria (1944–1989) and Port Said (1926–1987), north of the Nile delta coast, indicate a submergence of the land and/or a rise of the sea-level of 2 and 2.4 mm/yr, respectively.Dramatic erosion has occurred on some beaches of the Nile Delta. This is greatest at the tips of the Rosetta and Damietta promontories, with shoreline retreat up to 58 m/yr. Relationship between the shoreline retreat and sea level trends in terms of correlation analysis and application of the Bruun Rule indicates that the sea level rise has, by itself, a relatively minor effect on coastal erosion. The sea-level trend at the Nile delta coast is found to be only one of several effects on shoreline retreat. Major recent effects include a combination of cut-off of sediment supply to the coast by damming the River Nile and local hydrodynamic forces of waves and currents. Estimates of local future sea-level rise by the year 2100 at Alexandria and Port Said, respectively, is expected to be 37.9 and 44.2 cm. These expectations, combined with other factors, could accelerate coastal erosion, inundate wetlands and lowlands, and increase the salinity of lakes and aquifers.     

Sea-level rise and shoreline retreat of the Nile Delta promontories,Egypt

Studies of the Nile Delta coast have indicated wide values of local subsidence, ranging from 0.4 to 5 mm/yr. Trend analysis of sea-level rise and shoreline retreat at two Nile Delta promontories have been studied. Records from tide gauges at Alexandria (1944–1989) and Port Said (1926–1987), north of the Nile delta coast, indicate a submergence of the land and/or a rise of the sea-level of 2 and 2.4 mm/yr, respectively. Dramatic erosion has occurred on some beaches of the Nile Delta. This is greatest at the tips of the Rosetta and Damietta promontories, with shoreline retreat up to 58 m/yr. Relationship between the shoreline retreat and sea level trends in terms of correlation analysis and application of the Bruun Rule indicates that the sea level rise has, by itself, a relatively minor effect on coastal erosion. The sea-level trend at the Nile delta coast is found to be only one of several effects on shoreline retreat. Major recent effects include a combination of cut-off of sediment supply to the coast by damming the River Nile and local hydrodynamic forces of waves and currents. Estimates of local future sea-level rise by the year 2100 at Alexandria and Port Said, respectively, is expected to be 37.9 and 44.2 cm. These expectations, combined with other factors, could accelerate coastal erosion, inundate wetlands and lowlands, and increase the salinity of lakes and aquifers.     

Sedimentology and petrology of Quaternary sediments from the Hellenic Trench, Mediterranean Ridge and the Nile Cone from D.S.D.P., Leg 13, cores

Fifty-three samples from D.S.D.P. Sites 127, 128 (Hellenic Trench), 130 (Mediterranean Ridge) and 131 (Nile Cone) ranging in size from clayey silt to sand were submitted to grain-size and compositional analyses. The former confirmed the evidences obtained from the visual observation of the sedimentary features as to the presence of turbidites (Sites 127, 128, 131) and fluxoturbidites (Site 131). The cumulative frequency distributions of the latter are closely similar to those obtained from ancient deposits of the same type. The X-ray quantitative analyses of the total samples showed that at both Site 127 and Site 128 calcite and phyllosilicates make up together, on average, about two-thirds of the total composition. Quartz averages about 20%. Dolomite, plagioclase and K-feldspars are present subordinately in this order; the former, observed in all samples, is both detrital and authigenic. In the Nile Cone quartz comprises, on average, about 70% of the composition. Phyllosilicates, plagio-clases and K-feldspars were observed in minor quantities. The four samples of the Mediterranean Ridge, although Nile derived, show a composition closer to the Hellenic Trench samples than to the Nile Cone. This is due to the strong control exerted by the grain size on the quantitative mineralogical composition. The microscopic analyses carried out on both light and heavy minerals of the sand fraction and the clay mineralogy clearly differentiate between the Hellenic Trench and all the Nile derived sediments (Sites 130 and 131) and exclude an intermixing of even the finest fractions. Each group is well clustered in the compositional diagrams. The Hellenic Trench sediments could be classified as lithic arenites (Crook, 1960) or greywackes (Malesani & Manetti, 1970) and the Nile Cone sediments as sublabile lithic feldspathic arenites or feldspathic subgrey-wackes. The semi-quantitative clay mineralogy showed that, on average, almost 50% of the Nile derived clay sized sediments is montmorillonite. Mixed layer minerals make up a relevant part of the remaining fraction. In contrast, the Hellenic Trench sediments show lower quantities of montmorillonite (about 10%) and prevailing percentages of illite and chlorite. Kaolinite is present only in the latter samples and not in the Nile Cone sediments. The lack of relevant changes in the composition of the Nile Cone sediments along the cored sections of the holes suggests that the present hydrography of the Nile River dates from at least the Lower Pleistocene.     

Evolution of the modern Nile delta promontories: development of accretional features during shoreline retreat

The active accretional features that have developed along the modern Nile Delta promontories during shoreline retreat are analysed using topographic maps, remote imagery, ground and hydrographic surveys, together providing 15 time-slice maps (1922–2000) at Rosetta and 14 time-slice maps (1909–2000) at Damietta. Small double sandy spits developed and persisted at Rosetta between 1986 and 1991. At Damietta, a much larger single spit, 9 km long, formed approximately east of the mouth of the Damietta Nile branch between 1955 and 1972, although its source has now been depleted. Both the Rosetta and Damietta inlets are associated with submerged mouth bars that accumulated prior to the damming of the Nile, but that continue to contribute to local sedimentation problems, particularly at Rosetta. The development of the active accretional features along the Nile promontories reflects a combination of factors including sediment availability, transport pathways from source areas, a decrease in the magnitude of Nile flood discharges, as well as the impact of protective structures at the river mouths.     

Time-temperature and organic maturation relations at some wells at the northern Nile Delta,Egypt

Integrated time-temperature analysis of seven wells along an east-west profile in the northern Nile Delta is carried out. The level of organic metamorphism (LOM), total maturity level (ΣMAL) and total time-temperature index (ΣTTI) are calculated in order to identify the most appropriate analytical method of calculation of the maturation level inside each well at each sediment layer. Sediments in four of the seven wells (Sidi Salim, Abadiya, Abu Madi and El-Wastani) are found to have entered the oil window, as deduced from the three techniques. In Qawasim well, the LOM and ΣMAL show that this well enters the oil window at a specific depth. For the following wells, the mature depths are found to be 4031 m (Sidi Salim), 3777 m (Qawasim), 3717 m (Abadiya), 3603–4155 m (Abu Madi) and 3713 m (El-Wastani). The LOM method is found to quantitatively overestimate the level of organic metamorphism at shallow depths, and underestimate it at deeper levels relative to the other two maturity techniques. The ΣMAL and ΣTTI give results which compare more closely with previous published work than the LOM.     

Evaluating the effectiveness of bank infiltration process in new Aswan City, Egypt

Riverbank filtration (RBF) is an efficient and low-cost natural alternative technology for water supply application in which surface water contaminants are removed or degraded as the infiltrating water moves from the river to the pumping wells. In this study, a full-scale RBF site consisting of three vertical wells installed 50 m from Nile bank was investigated. The RBF systems are particularly well suited for providing better water quality than withdrawal directly from the Nile River to produce drinking water for New Aswan city. The study is carried out by taking samples over 1 year from riverbank filtrates wells, Nile River (as induced surface water), and some production wells were collected and analyzed. Physicochemical and microbiological measurements such as turbidity, dissolved oxygen, total suspended solids, total organic carbon, total dissolved solids, electrical conductivity, pH, Fe, Mn, NH₃, NO₂, NO₃, PO₄, Ca, Mg, Na, K, HCO₃, SO₄, Cl, total bacteria, and total coliform were carried out. The results of bank filtrate were compared with those of the natural groundwater and previous reported Nile water. Chemical and bacterial quality parameters of RBF are under the allowable limits for drinking water. Moreover, bank filtration is simultaneously improved the ambient groundwater and cleaned Nile water in the studied area. Result of this full-scale RBF plant showed the effectiveness of riverbank filtration as a proven treatment technique in Nile Valley with a fraction of cost comparing to conventional surface treatment plants.     

Short contribution: Nile flow failure at the end of the Old Kingdom,Egypt: Strontium isotopic and petrologic evidence

Strontium isotopic and petrologic information, obtained from sediment cores collected in the Nile delta of Egypt, indicate that paleoclimatic and Nile baseflow conditions changed considerably from about 4200 to 4000 cal yr B.P. in the Nile basin. Our study records a higher proportion of White Nile sediment transported during the annual floods at ca. 6100 cal yr B.P. than towards 4200 cal yr B.P., at which time suspended sediment from the Blue Nile formed a significantly larger fraction of the total load. This resulted from a decrease in vegetative cover and an increase in erosion rate accompanying the marked decline in rainfall. These new geoscience data indicate major changes in annual flooding and baseflow of the river Nile, marked short‐term paleoclimatic‐related events that may in part have led to the collapse of the Old Kingdom. © 2003 Wiley Periodicals, Inc.     

Geophysical surveys to investigate the relation between the Quaternary Nile channels and the Messinian Nile canyon at East Nile Delta, Egypt

This paper compares the pattern of historical Eastern Nile Delta branches, delineated by geoelectric resistivity investigation, with the path of the Nile canyon of Messinian time revealed in seismic reflection. A close correlation is evident between the Late Quaternary Nile River channels and the Messinian canyons (wadies) in the eastern Nile Delta. This indicates that the Messinian canyons were a persistent topographic (or geomorphic) feature until historical branches. The results may also have implications for long-term patterns of subsidence in the delta area.     

Heavy minerals and the evolution of the modern Nile

Heavy mineral analysis is a useful tool in tracing the changes in the hydrographic setting of the Nile through time. Analyses by the writer and others are presented to differentiate between a former Nilotic system, a Proto-Nile, and the modern Nile system, and to demonstrate the changes undergone by the modern Nile.The Proto-Nile was almost totally dependent upon discharge from equatorial and sub-equatorial tributaries in East Africa and from local Sudano-Egyptian affluents. The modern Nile system, in contrast, is dominated by contributions from the Blue Nile and the Atbara River, which drain the Ethiopian Plateau. The discharge of these rivers is governed by the monsoonal rains which are responsible for the summer floods in the Lower Nile Basin. It has been generally believed that this riverine system is very recent, perhaps not much older than 20,000 years. The evidence presented in this paper indicates that the Modern Nile system was well established by the later part of the Middle Pleistocene. In its early stage, the modern Nile was characterized by greater contributions from the non-Ethiopian East African and Sudano-Egyptian tributaries than at present.     

Quantification of River Nile/Quaternary aquifer exchanges via riverbank filtration by hydrochemical and biological indicators,Assiut, Egypt

This study approach seeks to characterize the hydraulic interactions between the Nile and the Quaternary aquifer via riverbank filtration (RBF) in Abu Tieg area, Assuit Governorate. The substantial removal/reduction of the most problematic substances during percolation of Nile water into abstraction wells was investigated using physico-chemical and biological indicators. Four sites with 11 municipal wells (20–750 m from the Nile) tapping the alluvial aquifer that is fed by the riverbank infiltrate were monitored. Bank-filtrated water was compared with those of the Nile and groundwater. Results showed that infiltrated Nile water ratio into the wells ranged from 39 to 80% reflecting the effect of distance from the Nile. Removal efficiency of total algal, total and faecal coliforms in bank-filtered water was 99.9%, while turbidity removal ranged from 93 to 98%. Fe, Mn and Zn in the bank-filtered water were relatively higher than those in the Nile, but were still under the allowable standards except those of Mn. LSI and WQI for the bank-filtered water indicated that the water was ranked as non-corrosive and of excellent quality. Comparison of physico-chemical and microbiological characteristics of the bank-filtered water with those of the Nile and groundwater showed the high efficiency of RBF as a treatment technology with minimal cost compared to conventional methods.     

Climate change and its impacts on the coastal zone of the Nile Delta,Egypt

The main objectives of the current work are (1) to determine historic pattern of shoreline changes (erosion and accretion) along the north coast of the Nile Delta, (2) to present a future view on what to be expected regarding climate change impacts, sea-level rise (SLR) scenarios, expected land losses and alteration of some soil characteristics (3) to recognize negative impacts of SLR on the Nile Delta coast and (4) to assess and suggest protection measures. The current investigation was conducted using the advanced techniques of remote sensing and geographic information system. The investigated area with 394 measured locations is located along the northern coast of the Nile Delta between Alexandria and ElTina plain in Sinai peninsula exactly between 29°20′ and 32°40′ E and 29°54′ and 31°35′ N with the minimum erosion values of 1.11 m², maximum of 6,044,951.64 m² and total of 16.02 km². On the other hand, 177 sites showed minimum accretion values of 0.05 m², maximum of 2,876,855.86 m² and total of 13.19 km². SLR was determined by applying the quadrant equation for 10-year intervals using 1990 as the base year. Mediterranean SLR along the Nile Delta coast could be estimated considering three different scenarios (low 0.20 m, medium 0.50 m, and high 0.90 m). Impacts of SLR are divided into (1) primary and (2) secondary impacts. Over the coming decades, the Nile Delta will face greater threat due to SLR and land subsidence as well. Regarding climate change and its impacts on soil characteristics, rapid increase in salinity values during the former three decades were found. This increase may be due to the intrusion of salty water of the Mediterranean. On the other hand, organic matter content decreased due to higher temperature, especially during the summer season. Some protection measures were assessed and suggested to combat or tackle SLR.     

Rejuvenation of dry paleochannels in arid regions in NE Africa: a geological and geomorphological study

Although the River Nile Basin receives annually ca. 1600 billion cubic meters of rainfall, yet some countries within the Basin are suffering much from lack of water. The great changes in the physiography of the Nile Basin are well displayed on its many high mountains, mostly basement rocks that are overlain by clastic sediments and capped by volcanics in eastern and western Sudan. The central part of the Nile Basin is nearly flat including volcanics in the Bayuda Mountains and volcanic cones and plateaus in southwestern Egypt. The high mountains bordering the Nile Basin range in elevation from 3300 to 4600 m.a.s.l. in the Ethiopian volcanic plateau in the east to ca. 3070 m.a.s.l. in the western Gebel Marra, and 1310 m.a.s.l. in the Ennedi Mountains in northwestern Sudan. In central Sudan, the Nile Valley rises approximately 200–300 m.a.s.l. In Egypt, the River Nile is bounded by the Red Sea Mountains in the east, assuming ca. 1000–2600 m.a.s.l., mostly of basement rocks, which are covered to the north of Aswan by Phanerozoic sediments sloping to the west, passing by the Nile Valley and continuing through the Western Desert. The Phanerozoic cover on both sides of the Nile is known as the Eastern and Western Limestone Plateaus. These plateaus assume elevations varying from 300 to 350 m.a.s.l. near the eastern bank of the Nile to 400–500 m.a.s.l. south Luxor at Esna and west of Aswan. The nearly flat Sahara west of the Nile Valley rises gradually westward until it reaches Gebel Uweinat in the triple junction between Egypt, Sudan, and Libya. Gebel Uweinat has an elevation of 1900 m.a.s.l. sloping northward towards the Gilf Kebir Plateau, which is 1100 m.a.s.l. The high mountains and plateaus in the southern and western Egypt slope gradually northward where the Qattara Depression is located near the Mediterranean coast. The depression is ?134 m.b.s.l., which is the lowest natural point in Africa. All these physiographic features in Sudan and Egypt are related to (i) the separation of South America from Africa, which started in the Late Paleozoic and continued up to the Cretaceous, giving rise to several generally E–W-oriented tectonic features inside Africa, (ii) the uplift of the Red Sea Mountains and their continuation inside Africa resulted in the East African Rift System (EARS), (iii) the Guinea–Nubia Lineament crossing Africa from the Atlantic to the Red Sea where many havoc trends, mostly E–W-trending faults, and uplifted basement features pierce the overlying sediments, (iv) parallel and longitudinal structures associated with volcanic plateaus and cones extend from west Sudan (Gebel Marra) to Ethiopian Plateau, passing by volcanics and plume features in between and the basins in east Africa were subjected to wrench related inversions, and (v) the Sudd linear E–W area stretching more than 1000 km between Gebel Marra in the west, passing by South Sudan and reaching southwestern Ethiopia. Here, fluviatile and subsurface waters led to ponds, lakes, and wet areas that are hard to exploit. The impact of these features led to the present south to north River Nile, but passing by many changes in the direction of its many tributaries and slope reversal of some of the major extinct rivers, either sectors of the main Nile or the rivers once flowed into the main river. The paleoclimatic changes during the Quaternary period: wet and dry have a great effect on the physiographic features and slope reversal of the Nile Basin drainage system.     

Provenance of temper in a New Kingdom Egyptian pottery sherd: Evidence from the petrology and mineralogy of basalt fragments

A New Kingdom spinning bowl from Karnak (Luxor) Egypt is similar in form to spinning bowls commonly found at other Egyptian sites and has a bulk chemical composition in the range for other Egyptian marl vessels. These data support a domestic origin. The matrix of the bowl contains unaltered, sand-sized, mafic rock fragments with volcanic, subophitic textures. Over 20% of the sand-sized grains consist of angular, unweathered rock fragments, and of these ∼20% are volcanic. Apparently they were added as temper. Electron microprobe analyses show that augite, plagioclase, and, where present, pigeonite, in nine of these have compositions typical of mafic igneous rocks. Geothermometry confirms crystallization at ∼1100°C. Pyroxene discrimination diagrams indicate geological sources ranging from within-plate alkali basalts to within-plate, continental tholeiites. Suitable sources for the temper are rare in Egypt. Both alkaline and tholeiitic, postorogenic (unaltered) late Cenozoic basalts occur in the Cairo area, making this the most likely but not the only possible source for the temper. The pottery may have also originated in Cairo because raw rock materials were moved upstream less commonly than down the Nile. A Cairo provenance for the Karnak artifact is consistent with the everyday movement of people and goods along the Nile between the ancient twin capitals of Memphis and Thebes. These results and the common occurrence of volcanic rocks as temper indicate that microbeam analytical techniques may help narrow the provenance of ancient pottery. © 1998 John Wiley & Sons, Inc.     

Saturated and unsaturated River Nile/groundwater aquifer interaction systems in the Nile Valley, Egypt

Surface water bodies interact with underlying aquifer systems, creating a complex flow system and flow paths. In general, a surface water body may be classified as gaining, losing, or flow through on the basis of its interaction with the surrounding aquifer. In the Nile Valley, the quaternary aquifer system is in a direct hydraulic interaction with the River Nile, canals, and drains. In this study, a regional numerical model was developed and used to evaluate the interaction between surface water bodies and the quaternary aquifer system in the Nile Valley. The solution is considered for a quasi three-dimensional, steady-state groundwater flow. The model used simulates the interaction between surface water bodies and groundwater for saturated and unsaturated flow conditions. In addition, a hydrodynamic model was used to simulate different extreme (high and low) scenarios for Nile surface water levels along the distance between Old Aswan Dam and Delta Barrages. Model calibration shows close results, and the model was used to simulate surface water levels. Results indicate that the Nile River acts as a drain for the quaternary aquifer (gaining water from the aquifer), although in the reaches upstream of the main barrages, the Nile loses the water, recharging the aquifer. All other main canals are recharging the aquifer system. The seepage rate depends mainly on the difference in piezometric head between the aquifer system and surface water bodies, as well as the hydraulic conductance of the base layer sediments of the surface water body. The model was used to evaluate the regional water balance for the Nile Valley and to estimate the surface water bodies' gains and losses.     

Hydro-environmental status and soil management of the River Nile Delta,Egypt

The sea level rise has its own-bearing on the coastal recession and hydro-environmental degradation of the River Nile Delta. Attempts are made here to use remote sensing to detect the coastal recession in some selected parts and delineating the chemistry of groundwater aquifers and surface water, which lie along south-mid-northern and coastal zone of the Nile Delta. Eight water samples from groundwater monitoring wells and 13 water samples from surface water were collected and analyzed for various hydrochemical parameters. The groundwater samples are classified into five hydrochemical facies on Hill-Piper trilinear diagram based on the dominance of different cations and anions: facies 1: Ca–Mg–Na–HCO₃–Cl–SO₄ type I; facies 2: Na–Cl–HCO₃ type II; facies 3: Na–Ca–Mg–Cl type III, facies 4: Ca–Na–Mg–Cl–HCO₃ type IV and facies 5: Na–Mg–Cl type V. The hydrochemical facies showed that the majority of samples were enriched in sodium, bicarbonate and chloride types and, which reflected that the sea water and tidal channel play a major role in controlling the groundwater chemical composition in the Quaternary shallow aquifers, with a severe degradation going north of Nile Delta. Also, the relationship between the dissolved chloride (Cl, mmol/l), as a variable, and other major ion combinations (in mmol/l) were considered as another criterion for chemical classification system. The low and medium chloride groundwater occurs in southern and mid Nile Delta (Classes A and B), whereas the high and very high chloride (classes D and C) almost covers the northern parts of the Nile Delta indicating the severe effect of sea water intrusion. Other facets of hydro-environmental degradation are reflected through monitoring the soil degradation process within the last two decades in the northern part of Nile Delta. Land degradation was assessed by adopting new approach through the integration of GLASOD/FAO approach and Remote Sensing/GIS techniques. The main types of human induced soil degradation observed in the studied area are salinity, alkalinity (sodicity), compaction and water logging. On the other hand, water erosion because of sea rise is assessed. Multi-dates satellite data from Landsat TM and ETM+ images dated 1983 and 2003 were used to detect the changes of shoreline during the last two decades. The obtained results showed that, the eroded areas were determined as 568.20 acre; meanwhile the accreted areas were detected as 494.61 acre during the 20-year period.     

The hydrochemical characteristics and evolution of groundwater and surface water in the western part of the River Nile, El Minia district, Upper Egypt

A combination of major and trace elements have been used to characterize surface- and groundwater in El Minia district, Egypt. Surface water versus groundwater chemistry data enabled geographical zonation and chemical types to be differentiated. The main target of this research is to investigate the groundwater quality and hydrochemical evaluation. The situation is further complicated by contamination with lithogenic and anthropogenic (agricultural and sewage wastewaters) sources and low plan exploitation techniques. The investigated Pleistocene aquifer is composed of sand and gravel of different sizes, with some clay intercalation. The semi-confined condition was around the River Nile shifted to unconfine outside the floodplain. The groundwater flow generally from south to north and locally diverts towards the western part from the River Nile. Fifty-six, 11, five, and two water samples were collected from the Pleistocene aquifer, River Nile, Ibrahimia canal, and Al Moheet drain, respectively. The collected water samples were analyzed for major and trace elements. The toxic metal concentrations of Al Moheet drain are higher than those in the River Nile and the Ibrahimia canal. Cr, Hg, As, and Cd concentrations in the River Nile and Ibrahimia canal are fluctuated above and below the WHO drinking standards. Se concentration in River Nile and Ibrahimia canal is below WHO drinking and irrigation guidelines. Total dissolved solid content in groundwater is generally low, but it is increased due to the western part of the study area. The geographic position of the River Nile, Ibrahimia canal, and Al Moheet drain impact on the groundwater quality. The PHREEQC confirm the high mixing proportions from the River Nile into the groundwater and decline away from it. In addition to the thicknesses of the Pleistocene, aquifer and aquitard layer enhance the River Nile and agricultural wastewaters intrusion into the aquifer system. The toxic metal concentrations (Pb, Cd, Cr, PO₄, Se, Mn, As, Hg, Ni, Al, Fe, and SIO₂) in groundwater were increased mainly in the northwestern and southeastern part (far from the River Nile). It is attributed to anthropogenic, high vulnerability rate (unconfined), and partially to lithogenic. In most localities, the groundwater are unsuitable for drinking and irrigation purposes with respect to Se concentration, while they are unsuitable for dinking according Mn, As, and Hg contents. There are some Cd and Pb anomalies concentrations, which cause severe restriction if used in irrigation. The results suggested that significant changes are urgently needed in water use strategy to achieve sustainable development.     

Mode of formation of the Nile Gorge in northern Egypt: a study by DEM‐SRTM data and GIS analysis

This is an overview of the mode of formation of the Nile Gorge in northern Egypt. It is based on the interpretation of the Shuttle Radar Topography Mission (SRTM) data along with detailed analysis of landsat image, geological map and seismic data. The results show that the current course of the Nile was caused by a differential uplift of two plateaus: Ma'aza, to the east, and Western Desert plateau, to the west of the river. This uplift is caused by dynamic forces resulting from subsurface convection processes. It also contributed to the formation of several drainage systems, basins and structural features. Abundant faults and fractures that are parallel to the Nile Valley on both flanks that are associated with uplift are proven to be contemporaneous with formation of the river. We conclude that understanding of the uplift is crucial to visualizing the Nile course and its geodynamic formation. The information derived from the SRTM data reveals invaluable knowledge in support of the presented remotely sensed geological features. The paper clearly explains the stages of formation of the Nile segments in space and time and structural controls on the path of the Nile River in Egypt. Copyright © 2015 John Wiley & Sons, Ltd.     

Evolution of the Nile deep‐sea turbidite system during the Late Quaternary: influence of climate change on fan sedimentation

This paper presents an overview of the evolution of the Nile deep‐sea turbidite system during the last 200 kyr, over a series of glacial to interglacial cycles. Six individual deep‐sea fans were identified from an extensive field data set. Each fan comprises a canyon, channel system and terminal lobes. Two of these fan systems were possibly active at the same time, at least during some periods. Large‐scale slope failures destroyed channel segments and caused the formation of new submarine fan systems. These slope failures thus played an important role in the overall evolution of the turbidite system. During the last glacial maximum (ca 25 to 14·8 ka) the central and eastern parts of the Nile deep‐sea turbidite system were relatively inactive. This inactivity corresponds to a lowstand in sea‐level, and a period of arid climate and relatively low sediment discharge from the Nile fluvial system. Rapid accumulation of fluvial flood‐derived deposits occurred across the shallower part of the submarine delta during sea‐level rise between ca 14·8 and 5 ka. The most recent deep‐sea channel–lobe system was very active during this period of rising sea‐level, which is also associated with a wetter continental climate and increased sediment and water discharge from the Nile. Increased sediment deposition in shallower water areas led to occasional large‐scale slope failure. The Nile deep‐sea turbidite system was largely inactive after ca 5 ka. This widespread inactivity is due to retreat of the coastline away from the continental shelf break, and to a more arid continental climate and reduced discharge of sediment from the Nile. The Nile deep‐sea turbidite system may be more active during periods of rising and high sea‐level associated with wetter climates, than during lowstands, and may rapidly become largely inactive during highstands in sea‐level coupled with arid periods. These acute responses to climate change have produced sedimentary/stratigraphic features that diverge from traditional sequence models in their nature and timing. This large‐scale sedimentary system responded to monsoon‐driven climate change and sea‐level change in a system‐wide and contemporaneous manner.