GIS and RS intelligence in delineating the groundwater potential zones in Arid Regions: a case study of southern Aseer, southwestern Saudi Arabia

Proterozoic basement aquifers are the primary source of water supply for the local populations in the Aseer (also spelled “Asir” or “Assir”) province located in the southwest of Saudi Arabia (SA) since high evaporation rates and low rainfall are experienced in the region. Groundwater assets are receiving a lot of attention as a result of the growing need for water due to increased urbanization, population, and agricultural expansion. People have been pushed to seek groundwater from less reliable sources, such as fracture bedrocks. This study is centered on identifying the essential contributing parameters utilizing an integrated multi-criteria analysis and geospatial tools to map groundwater potential zones (GWPZs). The outcome of the GWPZs map was divided into five categories, ranging from very high to negligible potential. The results concluded that 57% of the investigated area (southwestern parts) showed moderate to very high potentials, attributed to Wadi deposits, low topography, good water quality, and presence of porosity and permeability. In contrast, the remaining 43% (northeastern and southeastern parts) showed negligible aquifer potential zones. The computed GWPZs were validated using dug well sites in moderate to very high aquifer potentials. Total dissolved solids (TDS) and nitrate (NO32−) concentrations were highest and lowest in aquifers, mainly in negligible and moderate to very high potential zones, respectively. The results were promising and highlighted that such integrated analysis is decisive and can be implemented in any region facing similar groundwater expectations and management.