Browsing by Author "Elewa, Hossam Hamdy"

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The Contribution of Geographic Information Systems and Remote Sensing in Determining Priority Areas for Hydrogeological Development, Darb el-Arbain area, Western Desert, Egypt
(2010) Elewa, Hossam Hamdy; Fathy, Rafik Galal; Qaddah, Atef A.
"The Darb el-Arbain study area is in the southern Western Desert of Egypt and has been attracting increasing developmental interest in the last few decades, especially since agricultural development of the southern Baris area, where the groundwater resources of the Nubian Sandstone Aquifer System (NSAS) have been utilized for the cultivation of valuable lands. Due to the proven high potential of both groundwater and land resources, determining the priority areas for sustainable hydrogeological development becomes a necessity. A geographic information system, as a platform for geospatial modeling techniques, has been built, which depends on the recently collected data about the NSAS, in addition to the published databases. Certain criteria of practical value, like depth to groundwater, hydraulic conductivity, groundwater salinity, sodium adsorption ratio, and the safe yield of wells, were selected as decisive parameters for hydrogeological prioritization. The model pinpoints areas characterized by favorable hydrogeological conditions, which could be used for future development and implementation of an artificial storage and recovery (ASR) program. The designated priority areas for hydrogeological development occur at the southern, middle southern and some localized northern parts of the Darb el-Arbain area. The newly formed Tushka Lakes represent a suitable and excellent natural source of freshwater for implementing an ASR program."
Groundwater in the Eastern Desert with Reference to Application of Remote Sensing and GIS
(2007) Elewa, Hossam Hamdy
"The Eastern Desert of Egypt comprises almost one-fourth of the land surface of Egypt and covers an area of about 222117 km2. The northern tier is a limestone plateau, consisting of rolling hills, stretching from the Mediterranean coastal plain to a point roughly opposite Qena town on the River Nile. Near Qena, the plateau breaks up into cliffs about 487 m high and is deeply scored by wadis, which make the terrain very difficult to traverse. The outlets of some of the main wadis form deep bays, which contain small settlements of semi nomads. The second tier includes the sandstone plateau from Qena southward. The plateau is also deeply indented by ravines, but they are relatively free from obstacles, and some are usable as routes. The third tier consists of the Red Sea Hills and the Red Sea coastal plain. The hills run from near Suez town to the Sudanese border; they are not a continuous range but consist of a series of interlocking systems more or less in alignment. They are geologically complex, with ancient igneous and metamorphic rocks. These include granite that, in the neighborhood of Aswan area, extends across the Nile Valley to form the First Cataract—that is, the first set of rapids on the river. At the foot of the Red Sea Hills the narrow coastal plain widens southward, and parallel to the shore there are almost continuous coral reefs."
Groundwater Potentiality Mapping in the Sinai Peninsula, Egypt, Using Remote Sensing and GIS-Watershed -Based Modeling
(2011) Elewa, Hossam Hamdy
"Systematic planning for groundwater exploration using modern techniques is essential for the proper utilization, protection and management of this vital resource. Enhanced Thematic Mapper Plus (ETM+) images, a geographic information system (GIS), a watershed modeling system (WMS) and weighted spatial probability modeling (WSPM) were integrated to identify the groundwater potential areas in the Sinai Peninsula, Egypt. Eight pertinent thematic layers were built in a GIS and assigned appropriate rankings. Layers considered were: rainfall, net groundwater recharge, lithology or infiltration, lineament density, slope, drainage density, depth to groundwater, and water quality. All these themes were assigned weights according to their relative importance to groundwater potentiality and their corresponding normalized weights were obtained based on their effectiveness factors. The groundwater potentiality map was finally produced by WSPM. This map comprises five gradational groundwater potentiality classes ranging from very high to very low. The validity of this unbiased GIS-based model was tested by correlating its results with the published hydrogeological map of Egypt and the actual borehole yields, where a concordant justification was reached. The map declared that the Sinai Peninsula is generally of moderate groundwater potentiality, where this class encompasses an area of 33,120km2 which represents 52% of its total area."
Hydrogeochemical and Environmental Isotopic Evaluation
(2005) ABDEL SAMIE, S. G.; Elewa, Hossam Hamdy
"Water resources in Ain El Sukhna area play an important role in providing a source of potable water for land use and construction of new settlements. Hydrogeology, geochemistry and environmental isotopes were integrated in this study to assess groundwater resources recharging. The structural setting of the study area affected to a great extent the hydrogeological regime of the aquifer systems of the study area and resulted in the initiation of fracture or flowing springs. This same setting, especially the deep-seated faults, was responsible for the hydrochemical and isotopic composition of the groundwater of the study area. The water level at the area of the Miocene aquifer in the northern parts of the study area is higher than that of the Quaternary aquifer areas. This means that, the Miocene aquifer is the main source of recharge to the Quaternary aquifer. The main flow of water in the study area is directed from west, northwest and south to east and southeast. This gave evidence that the main recharge is coming from the upland areas, which lead to rainfall water storage in the sediments of these areas. Chemical measurements on groundwater indicate significant variations in solute content. Its lowest values were detected at delta W. Ghaweibba and gradually increase toward the Gulf shore. The general trend of increasing salinity is directed eastward. All samples coincide with the prevalence of Cl-Na as dominant ions and one salt assemblage (NaCl, MgCl2, MgSO4, CaSO4, and Ca (HCO3)2). The increase in Ca2+ ions concentration is mainly attributed to the saturation conditions in most water samples with respect to calcite and dolomite minerals. The isotopic results of O-18, D, C-13 and C-14 dating reveal three distinct recharge sources replenishing the Quaternary aquifer with different mixing ratios: 1. Paleowater from older formation (the Nubian Sandstone aquifer) seeping eastward via geological structures in Gebel El Galala El Bahariya represented by the issuing water samples (this water is denoted by isotopic depletion, old age (11,240 yr. B.P), and relatively high salt content), 2. Groundwater of Ain El Sukhna thermal flowing water with less isotopic depletion and age determination of 7000 yr. B.P and, 3. Recent recharge by infiltration of flash floods water after rainstorms over the hydrographic basins replenishes the aquifers directly on a short travel time. This water is isotopically enriched and has the signature of the Mediterranean Sea precipitation. C-13 measurements provided another confirmation of the diversity of recharge sources, where the issued water samples flow through aquifers less in carbonate minerals content (depleted in C-13). Whereas the groundwater samples are in contact with carbonate minerals cause a relative enrichment in C-13 isotopes. Marine residual deposits from the sequential regression and transgression of sea water are the main source of mineralization which is evidently observed from the low difference in isotopes with respect to salt content."
Potentialities of Water Resources Pollution of the Nile River Delta, Egypt Hossam Hamdy Elewa
(2010) Elewa, Hossam Hamdy
"The population growth, economic development with the consequent anthropogenic activities at the Nile Delta of Egypt addresses the present-day hydro-environmental status and quality deterioration trends of surface Nile River water. The hydrochemical fingerprints of surface waters revealed the effects of points and non-points sources of pollution. The relative low Cl- and SO42- in Nile water of Damietta and Rosetta branches precludes subjacent sources of polluted water. Mixing of surface Nile waters with other drainage polluted ones was revealed by Ludwig-Langelier and Piper diagrams, where there is a general tendency towards no-dominant water type’s regime in the Nile River branches with a certain modification in the hydrochemical facies of the drains waters. This modification is due to their pollution by point and non-point sources. The general tendency of water quality deterioration is generally towards the north. The pattern given by the multivariate statistical clustering technique for water quality discrimination indicated that the chief pollution sources prevalent had some commonality, which reveals similar phenomena of mixing and deterioration pattern, as the water, in general, is coming from one source (Nile River), which was subsequently modified by the natural and anthropogenic activities. The picture with respect to the nature of existing pollutants revealed the tendency of areas associated with parameters like the anthropogenic activities are getting widespread (not concentrated) over the whole area of study."
Prediction of Future Drawdown of Water Levels of the Pleistocene Aquifer System of Wadi El-Assiuti Area, Eastern Desert, Egypt, as a Criterion for Management and Conservation
(2008) Elewa, Hossam Hamdy
"Wadi El-Assiuti designates a remarkable dry drainage basin in Middle Egypt. The Pleistocene groundwater aquifer of this area represents the main water source used for reclamation and domestic purposes. The increasing number of groundwater wells drilled at the entrance ofWadi El-Assiuti in recent years, with its consequent over consumption of the groundwater reservoir, seems to be the clear-cut cause for groundwater levels drawdown and quantity deterioration. The constructed flow net map for the Pleistocene aquifer system sketched a pattern of piezometric pressures and flowdirections. The regional water flow is from east–northeast towards west–southwest directions, with some adverse minor directions at the north-central part of the study area. This map declared the areas suffering from over pumping (piezometric lows). However, usingempirical formulae and assumptions, the expected drop of piezometric levels of groundwater in the Pleistocene aquifer, as future scenarios, was predicted for 5, 10 and 20 years. These future scenarios reflected the urgent need for a policy or management scheme to decrease the severe drawdown of water level in this important developmental area."
Recent Recharge Possibilities Determination of the Pleistocene Aquifer System of Wadi El-Assiuti Basin, Egypt Using Hydrogeochemical and Environmental Isotopic Criteria
(2005) Elewa, Hossam Hamdy; Fathy, Rafik Galal
"Wadi El-Assiuti is one of the largest dry wadis in Middle Egypt. It comprises prolific groundwater potentialities and suitable lands for agricultural expansion. Twenty one groundwater samples are recently collected from the drilled water wells tapping the Pleistocene groundwater aquifer. The groundwater salinity values vary generally from 580 mg/l to 2445 mg/l indicating fresh to brackish water. The variation in water genesis could reflect the diversity of the recharge sources for the Early Pleistocene aquifer. The resistivity method is used where thirty vertical electrical soundings are measured in the field. It was able to delineate the groundwater aquifers and some concealed normal faults. The isotopic results of the collected surface and groundwater samples are widely varied from -8.9 to 2.81 ‰ for oxygen-18 and from -61.07 to 21.11 ‰ for deuterium. Almost 86 % of these samples fall in the depleted isotopic range, whereas the remaining percentage (14 %) is gradually enriched. Correlating the data points with respect to the Global Meteoric Water Line (GMWL) indicted the distribution of these points below the global line. The low slope and intercept values obtained from this correlation addresses the old origin of the main bulk of groundwater, which is represented by 86 % of samples. These samples carry the depleted isotopic signature of the paleowater characterizing the Eastern Desert of Egypt. The replenishment source of this water for the wadi proper could be from the local rainfalls on the upstream reaches of Wadi E-Assiuti, in addition to the underlying Nubia aquifer through a direct contact along deep seated faults. Towards the western reaches, at the entrance of the wadi (Nile Valley), the aquifer is almost recharged by the River Nile. The 14C age determination for two samples indicated that the Pleistocene water of Wadi El-Assiuti is mostly paleowater with a significant portion of relatively recent water recharging the aquifer from the rainfalls of the Red Sea mountainous area, in addition to the local ones."
Water/Land Use Planning of Wadi El-Arish Watershed, Central Sinai, Egypt Using RS, GIS and WMS Techniques
(2014) Elewa, Hossam Hamdy
"Water crisis in Sinai arid region is a major problem and urgently needs to be solved. When flash floods occur, the usual practice is to dispose the flood water into the sea without any benefit, except for a small portion that can be stored in the existing reservoirs. The present work applied an adopted strategy for determining the water/land use priority areas for development depending on the implementation of effective runoff water harvesting (RWH) techniques, side-by-side, with the using of available groundwater. This conjunctive water use gives an optimum pattern for water/land use in Wadi El-Arish watershed. For this sake, the geographic information systems (GIS), remote sensing satellite ETM+ images, watershed modeling system (WMS 8.0© Software) and GIS weighted spatial probability modeling (WSPM) were integrated to recognize the water/land use priority areas for agricultural and socio-economic activities. Four thematic layers represented by the volume of annual flood, groundwater prospective zones, suitability of geological units for agricultural development, and land slope of the basin were used to build the WSPM model within the ArcGIS 10.1© software platform. A map of water/land use priority areas for development was produced. This map classified the study area into five classes ranked from the very high (1906.49 km2) to very low (2441.56 km2) promising areas for new socio-economic settlements. The present article introduced a genuine proposal to utilize the locations of RWH constructions, i.e. dams, cisterns or surface water reservoirs to optimize the potentiality of sustainable development in the determined promising areas."