GEOELECTRICAL ASSESSMENT OF GROUNDWATER POTENTIAL OF KEANA AREA NORTHCENTRAL NIGERIA

This work was undertaken to unravel the hydro geophysical characteristics of Keana metropolis Nasarawa State, northcentral Nigeria. This study aims to assess and determine the sustainability of groundwater resources in Keana Town by using geoelectric techniques to collect data and analyze subsurface characteristics that can assist identify suitable sites for groundwater extraction. Once accomplished, it will give useful information for groundwater resource management and contribute to Keana's long-term growth. Fifteen (15) Vertical Electrical Sounding (VES) data with a maximum electrode spacing of (AB/2) of 200 meters were acquired using the Schlumberger electrode configuration. The VES data were interpreted using the conventional partial curve matching technique to obtain initial model parameters, which were used as input for computer iterative modelling using the IPI2WINTM software. The study revealed three (3) to six (6) geo-electric layers with underlying indurated sandstone and shale beds in some areas. In the study area, the apparent resistivity of the aquifer ranges from 32.4 to 407 m, with a depth ranging from 30 to 120m. Information extracted from iso-resistivity models and geoelectric cross sections revealed sandy strata with an exception around the northern portion i.e., around Federal Government Girls College Keana (FGGC) where a thick layer of shale is envisaged, extending to over 150 m depth with an average apparent resistivity value of 35Ω m. Thus, making the section fair to poor groundwater potential. However, this research has aided in delineating the groundwater potential of the area into three distinct zones.