Hydrogeological Investigation of Crystalline Basement Complex Aquifers in Katsina State

This study investigates the hydrogeological controls on groundwater occurrence in crystalline basement complex aquifers in Katsina State, North West Nigeria. Access to reliable groundwater is critical in Katsina State, where rainfall is highly seasonal and surface water sources are insufficient to meet growing demand. Groundwater in crystalline basement terrains occurs in weathered zones, fractures, and quartz vein systems whose distribution is controlled by lithology, structural geology, and topography. This study acquires 38 Schlumberger VES stations in Dutsi, Safana, and Mashi local government areas and integrates the data with lineament analysis performed on Landsat 8 satellite imagery and SRTM digital elevation models. VES data are inverted and interpreted as weathered zone and fractured basement layer models using IPI2WIN software. Lineament density maps are computed using ArcGIS and overlaid with VES interpreted depth maps. Aquifer hydraulic parameters are estimated using published correlations between layer resistivity, thickness, and hydraulic conductivity for crystalline basement terrains. Findings reveal that productive borehole sites are consistently associated with intersection of lineament clusters and maximum weathered zone thicknesses above 30 metres. Areas of lineament density exceeding 2 lineaments per square kilometre and weathered zone resistivity in the 20 to 80 ohm-metre range correspond with productive water point locations from the Katsina State Rural Water Agency database at 78 percent success rate. The study provides an integrated prediction model for borehole siting in Katsina State and recommends satellite lineament analysis as a standard pre-survey tool for groundwater exploration in the basement terrain.

Keywords: basement complex aquifer, crystalline terrain, lineament analysis, Katsina State, VES.