Assessment of groundwater potential using vertical electric sounding technique at Faculty of Medicine and Engineering, Federal University Dutsin-ma Katsina State, Nigeria

Abstract

Geophysical exploration is used to locate boundaries between different elements of the subsoil as these procedures depend on variations in the gravitational, magnetic, electrical, radioactive or elastic properties of the subsurface. Electrical resistivity method was employed to investigate the groundwater potential of the Faculty of Medicine and Engineering at permanent site of Federal University Dutsin-ma, Katsina State. The study was carried out using ABEM SAS 300 Terrameter, Schlumberger electrodes configurations were used to acquire 9 Vertical Electrical Soundings (VES) soundings. The VES data obtained were interpreted using Winresist computer software which reveal five (5) geoelectric layers, namely; the topsoil, laterite, weathered basement, fractured basement and fresh basement. The weathered and fractured layers constitute the aquiferous zone in all the stations. The results of the interpreted VES data showed that the resistivity of the topsoil varies from 17.1 to 109.8 Ωm with an average value of 137.7 Ωm. The thickness of the weathered basement varied from 1.7 to 7.9 m with an average value of 4.67 m, while depth to this layer varies from 4.6 to 13.8 m with an average value of 10.6 m. The thickness of the fractured basement varied from 3.0 to 15.6 m with an average value of 8.01 m, while depth to this layer varies from 6.3 to 33.7 m with an average value of 18.85 m. The depth to aquifer ranges from 17 to 69 m, the resistivity of the aquifer unit ranges between 35 and 830 Ωm. Based on the results, the potential VES points for groundwater exploitation in the study area includes VES 02, 03 and 05 which indicates low to moderate resistivity at greater depth and are therefore recommended for borehole establishment.