Exploration of Ground Water Potential of Federal University of Technology, Owerri and Its Environs Using Resistivity Survey

Abstract

The research focused on evaluating the groundwater potential in the vicinity of Federal University of Technology Owerri (FUTO) using a resistivity survey method. The investigation involved the utilization of eleven Schlumberger vertical electrical soundings (VES). The data collection was conducted using an ABEM Terrameter SAS4000 and then processed with IPI2Win Software, which relies on the conventional theory of curve matching. This process aimed to determine the depth, quality, and subsurface formations of the groundwater. The VES interpretation results revealed the presence of 3-5 geoelectric layers above the aquiferous layers. Various curve types were identified in the study area, including monotonically ascending (AA), bowed-ascending (HA), bowl-bell (HK), and ascending-bell (AK) curves. The majority of the field curves were found to be of the A-shaped type, signifying specific aquifer characteristics. The study indicated that the depth to the water table is relatively shallow in the Ihiagwa area, with an average depth of 7.26 meters. In contrast, the aquifer's depth is deeper around Avu, Nekede, and Eziobodo areas, with a mean depth of 32.33 meters. Obinze had very deep aquifers, with an average depth of 57.75 meters. Furthermore, the study established a relationship between aquifer characteristics and geoelectric parameters, allowing for the estimation of hydraulic conductivity and transmissivity values at all the sounding locations, even in areas lacking boreholes. These hydraulic characteristics showed that the aquifer had protective capacities ranging from 0.036 to 0.509 mhos, transmissivity values ranging from 11856.32 to 28661.28 m2/day, and hydraulic conductivity ranging from 13.47 to 1009.2 m/day. These values suggested that the aquifer materials are highly permeable, facilitating fluid movement within the aquifer. This research demonstrated the effectiveness of surface geophysics in estimating aquifer hydraulic characteristics, particularly in situations where pumping test data are unavailable. It also highlighted the vulnerability of the aquifer to surface contaminants. The findings are expected to be valuable for the long-term planning of groundwater exploitation projects in the study area.