Savanna Journal of Basic and Applied Sciences 1(2):169 - 174
Geoelectrical Evaluation of Groundwater Potentials of Shongom and Environs, Upper Benue Trough, Nigeria
Sani, M. A., Hamza, S. Y., Garba, I. and Usman, A.

The lack of pipe-bone water and ephemeral nature of the streams in the study area necessitates the utilization of groundwater for domestic use. To efficiently harness groundwater resources, the presence and depths of aquifers needs to be determined before drilling, this is best achieved by resistivity method of geophysical exploration. Previous work in the study area have shown that the water in the study area is safe for drinking and other domestic activities but the distribution and depths to groundwater aquifers have not been reported. This study is aimed at determining the presence and depths of groundwater aquifers at different locations in the study area. Vertical electrical sounding (VES) technique using schlumberger array was used to acquire the data at twenty six (26) different locations (VES station/point). The acquired data were processed using WinResist 2 software which gives a sounding curve, the number of geoelectric layers, thickness of the layers and their depths from the surface. The results shows that most parts of the study area are underlain by three to four geoelectric layers: high (> 90 Ωm) and fairly-high resistivity (40.9 – 74.4 Ωm) layers which are mostly encountered either close to the surface or deep down, medium resistivity (11.5 – 39.9 Ωm) layers and low resistivity (0.6 – 10.6 Ωm) layers which are suspected to be aquifers. The thickness of these geoelectric layers range from 0.6 m to 27.1 m. The fairly-high resistivity layers mostly consists the overburden while the high resistivity layers are suspected to be either crystalline rocks or highly indurated sedimentary rocks. Most parts of the study area are rich in groundwater and the aquifers are found within the porous and permeable sandstones of the Bima Group in the sedimentary areas, while overburden and fractured crystalline aquifers are found in areas underlain by the crystalline rocks at a depth range of 20 – 40 m.