Seismic Refraction Survey for Groundwater Exploration in Sokoto Basin, North West Nigeria

Groundwater scarcity remains a critical challenge in the Sokoto Basin, where communities in Sokoto and Kebbi states depend heavily on shallow aquifer systems that are increasingly vulnerable to depletion and contamination. This study applies seismic refraction techniques to map subsurface geological structures and identify viable groundwater zones across selected communities in the Sokoto Basin. The survey targets the characterisation of weathered and fractured basement zones that typically host significant groundwater reserves in this geopolitical region. Six traverses covering a total profile length of 1,800 metres were established, with hammer seismic sources deployed at standard intervals to generate compressional wave data. Time-distance plots were interpreted using the generalised reciprocal method to determine layer velocities and depths. Results were correlated with available borehole logs from the Sokoto State Rural Water Supply Agency to validate subsurface models. Preliminary findings indicate that the shallow weathered layer extends to depths of between 8 and 22 metres, with fresher basement rock identified at greater depths suitable for borehole siting. The study demonstrates that seismic refraction is a cost-effective and non-invasive tool for guiding borehole placement in areas with limited prior geological data. Recommendations are provided for optimal borehole locations, contributing to informed water infrastructure development in the North West zone. Keywords: seismic refraction, groundwater, Sokoto Basin, aquifer, weathered basement