Hydrogeology, log analysis, and hydrochemistry of unconsolidated aquifers south of El-Sadat City, Egypt

Agricultural and urban growth has increased the demands on groundwater supplies in areas east and west of the Nile Delta. The study area is about 80 km northwest of Cairo and about 15 km south of El-Sadat city, along the Cairo-Alexandria desert road. The aquifers in the study area are composed of sands and gravels with occasional intercalated clay beds. These sediments are Pleistocene and Miocene in age and are locally underlain by a relatively impermeable base of basalt. Two water-bearing zones are separated by about 25 m of clay and/or sandy clay beds. These zones are hydraulically interconnected by vertical flow of groundwater through the confining bed. Aquifer parameters and formation-water resistivity were evaluated from resistivity and neutron logs. Good agreement occurs between measured and estimated water resistivity. Chemical analyses of water samples indicate that groundwater is chemically homogeneous and low in total dissolved solids. The quality of water is excellent to good for irrigation.