Estimation of aquifer properties using electrical resistivity data in parts of Nsukka L.G.A., Enugu State

Abstract

The study was carried out to investigate the variation of hydrodynamic parameters in parts of Nsukka Local Government Area, Enugu State, via vertical electrical sounding (VES) technique employing Schlumberger electrode configuration. The results from measured parameters were used in estimating other parameters such as hydraulic conductivity, transmissivity, porosity, formation factor and tortuosity. The third layer was delineated as  aquiferous layer, with relative thickness compared to the overlying layers. The range of  results obtained shows a high variation of these parameters, hydraulic conductivity ranges from 0.0989 to 0.5079m/day with an average of 0.3025m/day. Transmissivity has range between 6.5779 and 57.9546m2 /day, with the average value of 18.7491m2 /day; porosity ranged from 27.6863 to 29.3226%, and its average is 28.6524%. Formation factor and tortuosity range from 0.00043 to 0.00049 and 0.1129 to 0.1167 respectively. Their variation was clearly displayed on the contour maps, and this was attributed to changes in properties of subsurface, such as grain sizes, pore shapes and sizes. The result of this study will be a useful guide in exploration and abstraction of groundwater repositories in the study area.