Hydrogeochemical approach including stable isotope study of groundwater in the Ketama region (Intrarif-Morocco)

Abstract

Groundwater plays a crucial role in maintaining ecosystem balance and supporting human activities. It is a valuable resource for drinking water supply, agricultural irrigation, and various industrial sectors. However, in the Ketama region, the quality and availability of this water are threatened by both natural and anthropogenic factors. This study analyzed the hydrogeochemical and isotopic characteristics of 164 groundwater samples collected from 40 wells, 51 boreholes, and 73 springs. The results show that 96% of the samples have electrical conductivity below 1000 μS/cm, indicating moderate mineralization. However, 12% of the samples had a pH below WHO guidelines, and 11% exceeded the maximum permitted nitrate concentration, pointing to localized contamination of agricultural origin. Analyses reveal a dominant HCO3-Ca facies (95% of the samples), primarily controlled by rock weathering, a key process in regulating water chemistry. Saturation indices (SI) indicate that gypsum and halite are unsaturated in all samples, promoting their continued dissolution. Conversely, 34.14% of calcite samples and 21.95% of dolomite samples were saturated, suggesting potential precipitation of these minerals. GIS maps were used to visualize the spatial distribution of critical parameters, providing tools for targeted resource management. Isotopic analyses reveal that the groundwater originates from precipitation of oceanic origin (Atlantic Ocean), enhancing understanding of aquifer sources and recharge mechanisms. These findings offer a robust scientific basis for advancing sustainable water resource management in the region, particularly in response to increasing challenges such as overexploitation and climate change impacts.