GEO-ELECTRICAL DELINEATION FOR GROUNDWATER RESOURCES OVER GIDAN-DOYA BASEMENT AREA, CENTRAL NIGERIAAbstract:
Groundwater development is very important in the survival of the human. This research was carried out in a newly developing area with population increase and agricultural development hence the need for this study. The objective is to carry out a geophysical investigation, delineate aquiferous zones, and groundwater potential for the study area. An electrical resistivity method for groundwater investigation using the Vertical electrical sounding (VES) technique was adopted. The survey involved three profiling and seven VES points using the Schlumberger configuration to delineate the subsurface lithologies and aquiferous zones within the study area. It was observed that the study area is composed of highly weathered and fractured rocks; hence there is a tendency for groundwater migration and accumulation in the weathered fractured horizons. Two geo-electric sections and a basement map were produced. The area generally showed four to five lithology units; which include topsoil, laterite, weathered basement, fractured basement, and the fresh basement. The thickness of the overburden ranges from 0 - 12.8m and the saturated layers have resistivity values ranging from 19.7Ωm - 849.8Ωm with depths to water range of 10.5m – 61.1m respectively. VES points 2, 4, and 5 showed good potential for groundwater with aquiferous unconfined zones ranging depths of about 45.0m - 60.0m. It was also deduced that areas, where thick overburden complemented with the presence of weathering and fractures within the study area, are zones for groundwater accumulation.