LAUSR

A detailed hydrogeological investigation is combined with electrical resistivity imaging using the Schlumberger depth sounding method in Garaat Sened, west-central Tunisia, to elucidate the hydrogeology and the hydrodynamics of this area with emphasis on their main controlling factors. Two types of aquifers with good reservoir qualities have been highlighted; however, their natural recharge is remarkably limited since the study area is characterized by semi-arid climate with an irregular rainfall ranging between 124 and 222 mm/y. The Mio-Plio-Quaternary siliciclastic constitutes an unconfined aquifer that outcrops along an area of ~ 125 km2; however, two other deep aquifers are enclosed within two fractured Upper Cretaceous carbonated formations in age (Abiod and Gattar). The excessive abstraction to satisfy the harmful agricultural practices and the domestic demands engender a critical balance between demand and natural renewable resources of these aquifers. This situation requires an emergency plan of management and rigorous policies to oppose the risk to groundwater availability.