Estimating the indices of inter-transmissibility magnitude of active surficial hydrogeologic units in Itu, Akwa Ibom State, southern Nigeria

Abstract

Itu Local Government Area is prone to groundwater contamination occasioned by saltwater due to the geographical location and the aquifer unit inter-transmissibility between the communicating/interconnected pores of the water-bearing units. This inter-transmissibility causes the continuous distribution of contamination among interconnected aquifer repositories. The study integrated the surface electric mapping and laboratory analysis of geologic samples and their corresponding water samples in estimating the transmissibility-dependent petrophysical parameters. The functional relationships between parameters have been determined. Maps of the spatial distribution of the estimated geohydraulic parameters have been drawn. Quantitative links of measured parameters to transmissibility have established. The resulting inferences based on the indices or magnitudes of the parameters measured helped in delineating the directions of water transmission within and across the hydrogeological units under study. The inferred result of permeability serves as a guide in identifying the southern zone of the area under study as having relatively reduced hydraulic pressure gradient differential, while the northern region has on the average, high hydraulic gradient differentials. The results of directions of inter-transmissibility of hydrodynamic properties in aquifer units are promising and capable of increasing the depth of knowledge on groundwater contamination and hence provide substantial input parameters that can enhance groundwater modelling within and near the study location.