____________________________________________________________________________________________ *Corresponding author: E-mail: nenyemos@yahoo.com; British Journal of Applied Science & Technology 2(4): 406-432, 2012 SCIENCEDOMAIN international www.sciencedomain.org Hydrogeophysical Delineation and Hydrogeochemical Characterization of the Aquifer Systems in Umuahia-South Area, Southern Nigeria C. Amos-Uhegbu 1* , M. U. Igboekwe 1 , G. U. Chukwu 1 , K. O. Okengwu 2 and T. K. Eke 3 1 Department of Physics (Geophysics),College of Natural and Applied Sciences, Michael Okpara University of Agriculture, Umudike, P.M.B 7267 Umuahia, Abia-State, Nigeria. 2 Department of Geology, University of Port Harcourt, P.M.B 5323 Port Harcourt, Nigeria. 3 Department of Physics/Electronics, Abia State Polytechnic, P.M.B 7166 Aba, Abia-State, Nigeria. Authors’ contributions This work was carried out in collaboration between all authors. All authors were actively involved in the field investigations. Author CAU designed the study and performed the statistical (graphical) estimation analysis of hydraulic parameters, and wrote the first draft of the manuscript. Authors CAU, MUI and GUC wrote the protocol. Authors CAU, GUC and KOO managed the borehole analyses of the study. Authors CAU, MUI, GUC and TKE carried out the geophysical data analysis. Authors CAU and TKE managed the literature searches. All authors read and approved the final manuscript. Received 13 th June 2012 Accepted 12 th November 2012 Published 2 nd December 2012 ABSTRACT In Umuahia-South Local Government Area of Abia State Nigeria, some cases of boreholes failure and groundwater discolouration have been observed. An investigation in order to determine the hydrogeological conditions of the area was carried out using geoelectrical, drill-hole and hydrogeochemical data. Using the Schlumberger electrode configuration, ten vertical electrical sounding data were acquired and the computer-aided Resist software method was used for further processing and interpretation. The interpretation of the VES data obtained from the study area shows that the vicinity of VES station 1 is likely to record Research Article