Only 14 pages are availabe for public view
Due to overpopulation and the increasing demand for water Egypt has faced many challenges regarding water resources. The new land reclamation is mainly counting on available and renewable water resources. The problem of how to accommodate large and growing water requirements is further complicated. Because of the pollution from all sources; agricultural, domestic and industrial. They limit how both fresh and wastewater can be used without adverse economic, environmental, and health implications. The backbone of these development projects is represented by the exploration and evaluation of the water resources with special emphasis to the groundwater in the desert outskirts.
The study area occupies a portion of the Western desert fringes El-Minia and Assiut Governorates. It includes the western old Nile alluvial terraces and the eastern part of the limestone plateau. The present work is an attempt aiming to investigate the groundwater conditions of the Eocene aquifer. It is based on geological, hydrogeological, hydrogeochemical and geophysical studies. The climate of the study area is arid to semi arid. It is hot, dry and rainless in summer. On the contrary, it is mild with rare rainfall in winter.
Geomorphological: The studied area includes the following land forms: 1- The young alluvial plains 2- The old alluvial plains 3- The Calcareous structural plateau. Two aquifers are recognized, Quaternary and Eocene aquifer. Eocene limestone aquifer units are represented by Minia Formation and Samalut Formation. Samalut Formation is consists of hard, white, highly fossiliferous limestone with shale and marl intercalations.
Geophysical: Field vertical resistivity measurements were carried out through 42 vertical electrical sounding stations. Some of these soundings were conducted beside wells of known depths and lithology. This is done mainly to recognize the resistivity ranges between the different rock types prevailing in the area and integrate these ranges allover the area. For the interpretation of the VES data, the method of automatic interpretation developed by Zohdy was used together with velpen’s iteration computer program. By the first method a multilayer model was calculated for each sounding curve. By the second method a reduced layered model was iterated until the calculated curve, fit the field curve. The parameters of the calculated curve would then represent the geoelectrical layering in the corresponding site. By presenting the interpreted data I the form of tables, cross sections and contour maps, it was possible to conclude the following:
Four geoelectric layers can be recognized in the studied area. The first layer has a resistivity range from less 39 to more than 4905 ohm. The thickness range between 1and 16.6 m. The high resistivity values of this layer can be attributed to loose sand and gravel. The recorded low resistivity value can be explained by the presence of cultivated clay lenses. The variation of resistivity range of the layer can be attributed to intercalation of different sediments such as fie silt, coarse sad ad gravel. The second layer has low resistivity values. This low resistivity range coincident with the sandy-clay deposits as recorded from the lithological logs. It appears as lenses rather than a layer and may be formed by river flood.
The third geoelectric layer shows moderate resistivity values and thickness. It represented the water-bearing formation and composed of saturated sand and gravel. The recorded high thickness of this layer can be explained by graben fault. High remarkable resistivity value is characterized the fourth layer. This layer represents the fractured limestone and considers the second aquifer in the area. The maximum thickness of Pleistocene aquifer is more than 101 m. Resistivity map of Eocene aquifer show that, it lies directly under the Pleistocene deposits and considers a heterogeneous aquifer as reflected from the calculated resistivity. The Pliocene clay is present.