Groundwater potential assessment using integrated multidisciplinary techniques in Shadadi, central Nigeria

Rising demand for potable water, rapid urban expansion, industrialization, and the essential role of water in human existence have increased pressure on groundwater resources. In Shadadi, central Nigeria, this pressure is compounded by numerous unproductive boreholes. This study integrated geographic information systems (GIS), remote sensing (RS), geological mapping, and geophysical techniques to account for geomorphological features and subsurface architecture. Seven thematic parameters were superimposed in GIS to develop a groundwater potential map (GWPM), and each criterion and subclass was evaluated, weighted, and normalized using the analytic hierarchy process (AHP). Interpreted vertical electrical sounding (VES) and geoelectric-section results, constrained by lithologic logs, delineated topsoil, sandy clay, weathered basement, fractured basement, and fresh basement layers. Aquifers occur within the weathered and fractured basement zones. Aquifer depth varies regionally, from less than 15 m in northern and western areas to more than 60 m in southern and northeastern sectors. The AHP-derived GWPM was classified into very high, high, moderate, low, and very low zones, representing 0.7%, 23.8%, 60.5%, 14.9%, and 0.1% of the study area, respectively. Validation using 49 drilled boreholes supported the reliability of the GWPM; Cohen's kappa was 0.78, indicating substantial agreement between observed and projected yield classes.