Salt Water Intrusion Characterisation in the Coastal Aquifer of Nabeul Hammamet Using Geophysical Methods

Abstract

A Time Domain Electromagnetic (TDEM) survey was carried out on the Mediterranean coast of Tunisia (Nabeul Hammamet), in order to delineate salt water intrusion into coastal fresh water aquifer detected by drilling wells. The survey was also carried out to determine the geometry of the fresh water aquifer and to identify the continuity between the aquifer system of Nabeul Hammamet and the contiguous aquifer system on the northern side (coastal aquifer of Korba). One dimensional interpretation of the TDEM data was correlated to existing data from borehole logs (Gamma Ray, Spontaneous Potential, Resistivity) . The results indicate that TDEM survey was able to map the interface between fresh and salt water and estimate depth to basement when siting new monitoring wells. Index Terms Coastal aquifer, Salt water intrusion, TDEM, Tunisia.