A surface geophysical survey was performed west El-Qasr area, in the Northwestern Coast of
Egypt, to clarify the geophysical characterization of the coastal aquifer. The study area is characterized by presence of
Pleistocene oolitic limestone aquifer that is contaminated by sea water intrusion. This aquifer represents the main
source of groundwater that used in agriculture projects along the coastal plain.
The integration between surface geophysical techniques including Vertical Electrical Sounding (VES), Two-
Dimensional Resistivity Imaging profiles (2-D) and Time Domain Electromagnetic Sounding (TDEM) are used
successfully to determine water bearing layers and their spatial distribution, outline the brackish water bearing layer
that is suitable for exploitation along the study area and to detect depth to brackish/saline water interface in the coastal
aquifer. TDEM sounding is proven as a successful method to trace brackish/saline water interface in the study area;
bulk resistivity of the water bearing layer below this interface was used to calculate the porosity of this aquifer by
applying Archie's equation; this aquifer has an excellent porosity values (33.0 %).
The combination between VES, 2-D and TDEM methods beside the available information from the existing wells is able
to decrease the ambiguity during the interpretation of the acquired data. Interpreted data of the surface geophysical
tools exhibit a good match between them and the proper sites for drilling new wells are recommended.