Application of Surface Geophysics to Groundwater Investigations: A Case Study of Rural Area in Ilorin, Northcentral Nigeria.

摘要

This study was carried out to determine groundwater potential in Ilorin, Northcentral Nigeria using Vertical Electrical Sounding (VES). The VES data was generated from twenty (20) locations in the study area and was later processed and analyzed using IPI2 WIN software. The underlying geo-electric sections comprises of topsoil, laterites, weathered basement, fractured basement, and fresh basement.The topsoil has resistivity and thickness ranges between 44.1- 862?m and 0.5 – 3.52m. The second layer which is laterites possess resistivity and thickness between 16.3 - 2001 ?m and 0.62 – 10.3m, The third layer is weathered basement having resistivity and thickness ranges from 11.0 – 755 ?m and 3.1 – 52.0m. The fourth layer considered as fractured basement has resistivity and thickness between 93.1 - 3247 ?m and 14.8 – 71.1m and final layer is fresh basement which possess resistivity ranges between 73.7 – 8444 ?m.The interpretation from the resistivity log of regolith rocks shows different curve types which include HA, HKH, QH, H and A – type curves. About 55% of the regolith in the area possesses aquifer potential value of 10.5 which shows optimum weathering and groundwater potential, therefore, any future borehole should be sited in these locations which are 3, 4, 8, 9, 10, 12, 13, 14, 16, 18, and 20. This study will provide a baseline hydrogeophysical data bank for prospective scientists, agriculturalists and relevant agencies that may be concerned with rural water supply and food security.