Keywords: Essaouira basin, coastal aquifers, hydrogeochemistry, mass balance model, MBM, water management, resource protection, groundwater resources, semi–arid zones, hydrochemical methodologies, Morocco, water–rock interaction, groundwater mineralisation
Management and protection of groundwater resources in semi–arid zones: application of hydrochemical methodologies to Essaouira Synclinal Basin, Morocco
The water resources of the Essaouira basin are characteristic of a semi–arid climate. It is a coastal aquifer located on the Atlantic coastline, corresponding to a sedimentary basin with an area of about 200 km². The geological structures delineate a syncline bordered by the Tidzi diapir of Triassic age which outcrops to the E and S. In the Essaouira basin, a multi–aquifer composed of detrital deposits of the Plioquaternary and Turonian dolomitic limestones was identified. The main flow direction is from SE to NW towards the Atlantic Ocean, the recharge area being located near the Tidzi diapir. In the Essouaira basin, groundwater is of Na–Cl–type. The chemical signature of these waters should be the result of the preferential recharge area that is located in the Tidzi diapir. It was possible to notice that there exists an important contribution of water–rock interaction in groundwater mineralisation, corroborating the influence of Tidzi diaper.