Evaluation of groundwater potential in part of Ahmadu Bello University, Zaria, Northwest Nigeria

Abstract The need to address the acute water shortage problem within the Ahmadu Bello University Zaria Campus in Samaru necessitated this groundwater exploration project. 2D geoelectric imaging and vertical electrical sounding (VES) surveys were carried out to investigate the groundwater potential of the study area. The 2D geoelectric models and sounding curves obtained were correlated with existing borehole logs obtained from the area, hence validating the results from the 2D resistivity survey. Results from the surveys showed three-layer lithologies with varying thicknesses and resistivity values. The topsoil showed resistivity values of between 4 and 170 Ωm, characteristic of clayey sand and sandy materials. The second layer is characterized by resistivity values ranging between < 4 and 90.6 Ωm, coinciding with zones of the weathered basement. The third layer which has resistivity values ranging between 90 and 550 Ωm constitutes the basement rocks. The thicknesses of the weathered regoliths favourable for groundwater exploration vary from 13.4 m around the Amina Hall, 16.7 m northeast-southwest of Akenzua Hall, 21.2 m northwest-southeast of Akenzua Hall, 24.3 m around Alex Hall and 25.3 m around the Suleiman Hall. These very important parameters reveal the groundwater potential of the study area and therefore suggest that groundwater can be developed and harnessed for use by the University but with a greater yield around the Alex and Suleiman Halls. VES survey was integrated with the 2D resistivity survey to provide information that compliment results from the 2D resistivity survey. The sounding curves were A-Type and H-type curves exhibiting low resistivity values (5–24 Ωm) within the second layer.