Evaluation of Groundwater Potentials Using Vertical Electrical Sounding Method in Zamfara Hostel, University of Ilorin, Kwara State, Nigeria

Abstract

Groundwater is a vital natural resource, especially in regions with limited surface water availability. This study assessed the groundwater potential of Zamfara Hostel, University of Ilorin, Nigeria, using the Vertical Electrical Sounding (VES) method. The study area is underlain by crystalline rocks of the Basement Complex, which are primarily high-grade metamorphic rocks, gneisses, and migmatites. These rocks typically have low porosity and permeability, but weathering and fracturing processes can enhance their groundwater storage capacity. Five VES points were established to evaluate the subsurface lithology and identify potential aquifer zones. The resistivity data were interpreted using IPI2Win and WinResist software, revealing a four-layer geo-electric sequence characterized by a resistive topsoil layer, a less resistive weathered basement, and a highly resistive fresh basement. The topsoil layer, with resistivity values ranging from 242.2 to 1021.8 Ωm, serves as the overburden, while the lateritic soil layer, with higher resistivity values (446.5 to 4132.2 Ωm), is less permeable. The weathered basement, with resistivity values ranging from 50.4 to 120.5 Ωm, was identified as the primary aquifer unit, with thicknesses varying from 6.4 to 34.2 meters. The fresh basement, with resistivity values exceeding 337.0 Ωm, was found to be impermeable. The study concluded that the area has medium groundwater potential, with the weathered and fractured zones serving as the main aquifer units. These zones are capable of storing and transmitting groundwater, making them suitable for borehole drilling. The findings provide valuable insights for groundwater management in the study area, particularly in addressing the water supply challenges faced by the growing population of the university community. This research highlights the importance of geophysical methods in groundwater exploration and contributes to the sustainable management of water resources in Basement Complex terrains.