Hydrogeochemical processes in rural coastal aquifer (Haha region, Morocco)

In arid and semi-arid regions, groundwater is the principal source of urban and rural water supply. Given that groundwater is the only source of water supply in the Haha region (Moroccan Atlantic coast), the evaluation of this vital resource, using the hydrogeochemical approach, is the main objective of this study. The interpretation of these analytical data showed that the chemical composition of the groundwater is of Ca-Mg-Cl, Na-HCO₃, and Na-Cl, with the dominance of the first type. Hydrochemical characteristics using the bivariate diagrams of major (Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO₃^-, Cl^-, NO₃^-, and SO₄^2-) and some trace elements (Br^- and F^-), mineral saturation indices, and statistical analysis show that the water-rock interaction, cation exchange processes, and marine effect are the main processes that control groundwater mineralization. Also, the majority of analyzed samples have concentrations above the thresholds for human consumption fixed by WHO, especially F^-, NO₃^-, K⁺, Cl^-, and HCO₃^- concentrations. This requires treatment of this groundwater before any consumption and domestic uses. For agricultural uses, the groundwater of the Haha region remains adequate, especially for plants, which can withstand water with electrical conductivity greater than 1000 µS/cm. However, the results obtained can be used as a basis for decision-makers for better water management in the Haha region.