Groundwater Exploration in Gifgafa Area, Central Sinai, Egypt

Groundwater is considered the main water resource, especially in desert, arid and remote areas, like Sinai. The study area of Gifgafa village is located in the central Sinai between latitudes 30º 25`and 30º 29` N and longitudes 33º 06` and 33º 11` E. This study mainly aims to identify the most promising site for drilling deep water well for developing this populated region. The area is covered by the Quaternary deposits, Upper Cretaceous, Lower Cretaceous and Jurassic rocks from top to bottom. Since the electric resistivity of rocks depends on porosity, permeability, water content and salinity of water; the main target of the geophysical survey was to identify the type and nature of the subsurface lithologic sequence in the study area. This was carried out by using Vertical Electrical Sounding technique (VES) of electric exploration, which was applied in three different sites and interpreted qualitatively and quantitatively using the computer program (RESIX-PLUS). Results indicated that, the investigated interval of subsurface section reached about 1200 m below ground surface starting with Quaternary deposits followed by limestone of Upper Cretaceous and ends with Lower Cretaceous sandy facies of indefinite thickness. The results of the geoelectrical resistivity data have closely confirmed the results of the lithological information of the drilled wells of El-Meliez and UNICEF in the study area. The hydrogeological condition, at the study area, is well represented by the presence of two main groundwater aquifers: 1) The fractured limestone aquifer has a total thickness ranging between 800-1000 meters; 2) The Nubian sandstone aquifer which has an average thickness of 150 to 300 meters. Accordingly, the most promising sites for deep water wells were recommended to be in the central part of the study area. So, the future development activities should be located within that part of the study area