Geoelectical Resistivity Method in Aquifer Characterization at Opic Estate, Isheri-Osun River Basin, South Western Nigeria
Investigation was carried out at Opic Estate in Isheri-Osun River Basin environment using Electrical Resistivity method to study saltwater intrusion into a fresh water aquifer system from the proximal estuarine water body. The investigation is aimed at aquifer characterisation using electrical resistivity method in order to provide the depth to which fresh water fit for both domestic and industrial consumption. The 2D Electrical Resistivity and Vertical Electrical Resistivity techniques alongside Laboratory analysis of water samples obtained from the boreholes were adopted. Three traverses were investigated using Wenner and Pole-Dipole array with multi-electrode system consisting of 84 electrodes and a spread of 581 m, 664 m and 830 m were attained on the traverses. The main lithologies represented in the study area are Sand, Clay and Clayey Sand of which Sand constitutes the aquifer in the study area. Vertical Electrical Sounding data obtained at different lateral distance on the traverses have indicated that the water in the aquifer in the subsurface is brackish. Brackish water is represented by lowelectrical resistivity value signature while fresh water is characterized by relatively high electrical resistivity and in some regionfresh water is existent at depth greater than 200 m. Results of laboratory analysis of samples showed that the pH, Salinity, Total Dissolved Solid and Conductivity indicated existence of water with poor quality, indicating that salinity, TDS and Conductivity is higher in the Northern part of the study area. The 2D electrical resistivity and Vertical Electrical Sounding methods indicate that fresh water region is at ≥200m depth. Aquifers not fit for domestic use in the study area occur downwards to about 200 m in depth. In conclusion, it is recommended that wells should be sunkbeyond 220 m for the possible procurement of portable fresh water.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1316041Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 549
 A. A. Alabi, R. Bello, A. S. Ogungbe, H. O. Oyerinde, Determination of groundwater potential in Lagos State University, Ojo; using geoelectric methods (vertical electrical sounding and horizontal profiling), Report and Opinion, 2(5): 68-75 (2010).
 J. O. Oseji, M. B. Asokhia, E. C. Okolie, Determination of groundwater potential in Obiaruku and environs using surface geoelectric sounding, Environmentalist, 26: 301-308 (2006).
 UNESCO, Groundwater resources of the World and their use. In: Zekster IS, Everett LG (eds), IHP-VI Series on Groundwater, 6 (2004).
 Todd, D. K., 1980. Ground Water Hydrology. John Wiley & Sons, Second Edition: 535.
 Okoro, E I; Egboka, B.C. E.; Onwuemesi, A. G. (2010). Evaluation of the aquifer characteristic of Nanka Sands using hydrogeological method in combination with Vertical Electrical Sounding (VES).
 Kelly, W. E. and Stanislav, M., 1993.Applied Geophysics in Hydrogeological and Engineering practice. Elsevier Amsterdam, pp: 292.
 Omosuyi, G. O., Adeyemo, A., and Adegoke, A. O, 2007. Investigation of groundwater prospect using electromagnetic and geoelectric sounding at Afunbiowo, near akure, south-western Nigeria. Pacific. J. Sci. Technol., 8:172-182.
 Asfahani, J., 2006. Geoelectrical investigation for characterizing the hydrogeological conditionsin semi- arid region in Khamasser valley, Syria. J. Arid environ., 68:31-52.
 Ismailmohamaden, M. I., 2005. Electric Resistivity Investigation at NuweibaHabbour Gulf of Agaba, South Sinai, Egypt. J. Aquatic Res., 31:57-68.
 Sung-HO, S. L. Jin-Yong and P. Mamsik, 2007.Use of vertical electrical soundings to delineate seawater intrusion in a coastal area Byunsan, Korea. Environ. Geol., 52: 1207-1219.
 Benkabbour, B., Toto, E. A. and Fakir, Y., 2004. Using DC resistivity method to characterize the geometry and salinity of the plioquartennary consolidated coastal aquifer of the mamora plain, Morocco. Environ. Geol., 45:518-526.
 Alile, O. M., Ujuanbi, O. and Evbuomwan, I. A., 2011.Geoelectric investigation of groundwater in Obaretin –Iyanomon locality, Edo state, Nigeria. Journal of Geology and Mining Research Vol. 3(1) pp. 13-20.
 Ekine, A. S, and Osobonye. S. (1996). Surface Geo-electric sounding for 20 J. Geol. Min. Res. The determinations of Aquifer characteristics in parts of Bonny Local Government Area of Rivers State. Nig. J. Phys., 85: 93-97.
 Telford, W. M., Geldart, L. P., and Sheriff, R. E., (1990). Applied Geophysics (2nd Edition). Cambridge University Press, Cambridge/New York/Australia. P 645-699.
 Emenike, E. A., 2001: Geophysical Exploration for groundwater in a sedimentary environment Global J. Pure Appl. Sci., 7(1): 97-102.