Geophysical Investigation of Groundwater Potential in Akwa Ibom State Polytechnic Campus, Ikot Osurua, Akwa Ibom State, South –South Nigeria Using Electrical Resistivity Method
Okon Peter, Udeme Inyang & Itoro Sampson
Akwa Ibom State Polytechnic, Ikot Osurua, Akwa Ibom State
Email: apostleop5family@yahoo.com
ABSTRACT
A geophysical investigation involving the vertical electrical sounding (VES) electrical resistivity method was carried out at Akwa Ibom State Polytechnic Campus ,Ikot Osurua, South-south Nigeria to determine the
subsurface layer parameters (resistivities, depth and thicknesses) with a view to determining the aquifer configurations which will assist in sitting high yield boreholes in the community.A total of four (4) vertical electrical sounding (VES) were conducted using the integrated Geo-instrument service (IGIS) resistivity meter to generate the field data. The Schlumberger sounding was carried out with current electrode spacing (AB) ranging from 1-300m. The distance used for the potential electrode spacing (MN) ranging from 0.25-10m. This array was employed in view of it resolution power and its reliability. The field data obtained were subjected to interpretation by partial curve matching and by computer iteration using IP12 WIN software.
The interpreted results were constrained by lithologic log to produce the geoelectric sections of the subsurface. Three (3) geoelectric layers were delineated and aquifer characterization of the area showed that the aquifer
resistivity is in the range of 89.2Ωm to 3287Ωm with corresponding thickness in the range of 40m to 80m although it varies in some locations. The result indicates the presence of fresh groundwater at this depth.
Keywords: Groundwater, aquifer, vertical electrical sounding (VES), Schlumberger configuration.
