Groundwater Mapping Through Integration of Resistivity Survey, Remote Sensing, Geographic Information Systems and AHP Techniques in Bwari Area Council, FCT Abuja, Nigeria

This study presents an integrated, multi-criteria approach to delineating groundwater potential zones in the Bwari Area Council, Federal Capital Territory, Abuja, Nigeria, employing a combination of Vertical Electrical Sounding (VES) resistivity surveys, remote sensing, Geographic Information Systems (GIS), and the Analytic Hierarchy Process (AHP). Using satellite imagery, DEMs, digitized maps, and field observations, thematic layers—rainfall, geology, slope, drainage density, land use/land cover, lineament density, soil type, and topographic wetness index—were generated and validated through GIS and remote sensing techniques. Weights were assigned to each factor using AHP, prioritizing parameters based on their hydrogeological significance. Thematic layers were integrated via weighted overlay analysis in ArcGIS to produce a spatially explicit groundwater potential map. Subsurface information was acquired through VES at 23 locations, with resistivity data interpreted to characterize aquifer properties (resistivity, thickness, depth, and overburden). The results reveal a dual aquifer system, comprising a shallow weathered zone and a deeper fractured basement aquifer, with groundwater occurrence predominantly controlled by secondary porosity features. Moderate-to- high groundwater potential zones were found to constitute over 85% of the study area, with high-potential regions associated with thick, weathered, and fractured lithologies, low drainage density, gentle slopes, and favourable land cover. Comparative analysis between the integrated thematic (RS/GIS/AHP) and aquifer-parameter (VES) models yielded a high correspondence (78.7%), confirming the reliability of the multi-criteria method and underscoring the importance of combining surface and subsurface data. The study advances methodological frameworks for groundwater assessment in crystalline basement terrains and provides a robust scientific basis for sustainable borehole siting, groundwater resource development, and land-use planning. The approach is replicable in similar hydrogeological settings, offering important implications for water resource management in data-scarce, complex geological environments.