Investigation of Aquifer Vulnerability under some Protective Measures in Ehime Mbano, South-Eastern Nigeria for Sustainable Groundwater Development

Abstract

This study focuses on assessing aquifer vulnerability to contamination in Ehime Mbano South-Eastern Nigeria by applying the DRASTIC model. The data was obtained using (VES) vertical electrical sounding technique by applying Schlumberger configurations with ^AB/₂ = 400 m. The VES data were interpreted using state of the art soft wares e.g. IP12WIN and Surfer 12 to obtain the final model for each VES, groundwater vulnerability map was also developed while aquifer media was gotten by taking into account, the depth at which water was struck and correlating those depths with the lithological description of the VES results obtained. The hydraulic conductivity was calculated from apparent resistivity of the aquifer. However, the net recharge, soil media, and topography was obtained from research documentaries. Aquifer vulnerability assessment carried out revealed areas with high, low and moderate vulnerability based on the DRASTIC Index. Locations with high vulnerability rating of 126 -165 includes: Umuokiri Umunumo and Ikperejere. Locations with moderate vulnerability rating of 86-125 includes: Ikpem, Ikweii Nzerem while locations with low vulnerability rating of 70-85 includes: Umuokara Uzinomi and areas close to Umueze II. The findings of the study can be used to identify regions of contamination of groundwater in the study area.