Aquifer Delineation Using Vertical Electrical Sounding In Ogale Community, Eleme Local Government Area Of Rivers State Nigeria.

Abstract

Five Vertical Electrical Soundings (VES) were carried out in Ogale Community, Eleme Local Government Area of Rivers State, to delineate aquifers in the area for the drilling of productive boreholes, using ABEM Terrameter SAS 1000. The interpreted geo-electric sections from the VES data and modelling curves revealed four geo-electric layers. The first geo-electric layer has resistivity value of 301ΩM and a thickness of 2.4m. This layer is interpreted as topsoil. The second geo-electric layer which has a resistivity value of 651ΩM with a thickness of 5M is interpreted as unsaturated fine sand. The third geo-electric layer which has a resistivity value of 2053ΩM and a thickness of 16M is interpreted as very coarse sand. The fourth geo-electric layer has a resistivity value of 1269ΩM with a thickness of 40M is interpreted as coarse sand. The third and the fourth layers are aquiferous and considered to be the target for drilling. The fifth geo-electric layer has a resistivity value of 598 ΩM, with both depth and thickness unknown. The geo-electric sections were compared with strata-log of a near-by well and these were correlatable. From this study, a benchmark of 24 meters  depth has been recommended to represent subsurface horizons saturated with freshwater in the study area.