Recharge Conceptual Model and Mineralization of Groundwater in a Semi-arid Region; Essaouira Basin (Morocco)

The geological setting of PQ and T aquifers system of Wadi Ouazi basin plays an important role in the geochemical and hydrodynamic characteristics of the groundwater systems, the most important source of water supply in Essaouira basin. The combination of hydrogeochemical and isotopic methodology applied in this investigation allowed a better understanding of the conceptual model of the aquifer response under present climatic regime. The chemical data indicate that dissolution of evaporate minerals (mainly halite and anhydrite), cation exchange process and sea spray, as the main processes controlling groundwater mineralization. The isotopic data show that the recharge is assured by precipitation of oceanic origin without notable evaporation; stable isotopes content allowed the identification of different recharge areas at different altitudes between the two aquifer systems.