STRATEGIC DEEP AQUIFER VALLEY CHARACTERIZATION USING AN INTEGRATED GEOPHYSICAL APPROACH (CENTRAL TUNISIA, SOUTHERN MEDITERRANEAN ARID PROVINCE)

Abstract

The joint interpretation of geophysical data provides an increasingly important integration of information able of characterizing our subsurface planetary resources. This paper is a demonstration of a case study, situated in an extremely limited water resources region, allowing to develop hydrogeological provinces. An integrated geophysical approach was implemented to clarify the structuring, the extension and geometry of the Miocene aquifer system located to the Sbetla basin (Central Tunisia, southern Mediterranean arid province).#xD;This significant hydrogeological basin is connected to the Tunisian North Water Transmission System for achieve sustainable drinking water supply of Sfax region with at least 1 million residents. The seismic, gravity and electrical methods were used together using advanced analysis (Residual-regional gravity separation, Electrical Resistivity Tomography generation form 1D Vertical Electrical Sounding, etc.). This specific methodology allowed us to reveal a NE-SW strategic deep Miocene aquifer valley segmented by NW-SE faulting corridors. This valley can record the maximum thickness of sandstone Miocene aquifer levels named respectively from deep to shallow levels G1, G2 and G3 separated by two aquitards called from deep to shallow levels A1 and A2. It can be considered as a preferential target zone to carry out new deep exploration drilling.