Natural Vulnerability Estimate of Groundwater Resources in the Coastal Area of Ibaka Community, Using Dar Zarrouk Geoelectrical Parameters

The study is aimed at estimating the natural vulnerability of groundwater resources using Dar Zarrouk geoelectrical parameters. Hence, ground-based earth resistance measuring device (OYO McOHM resistivity meter, Model 2115A) and its accessories were deployed for the study. 15 Schlumberger vertical electrical soundings (VES) points distributed along three profiles within the Mbo plain area were conducted. The VES field data were interpreted manually on bilogarithmic plot and then by applying the auxiliary point-partial resistivity curve matching technique. The interpretation was enhanced by sophisticated computer software (IPI2Win). The Dar Zarrouk geoelectrical parameters were deduced from the advanced interpreted results and use to produce contour maps. The lithology identified was of sands sequence of different grain sizes for aquifer zone. The absence of clay formation in the lithology log and low resistivity value (21.49 Ωm) at aquifer’s depth within the VES 5 column suggested saline water ingress. The low range of overburden thickness lies between 0.3 and 4.6 m. The associated overburden longitudinal conductance was found to range from 0.000 to 0.019 Siemens, which was generally low. Therefore, suggesting that groundwater resources in the study area are vulnerable to contamination. Hence, aquifers in the study area were considered to be at high risk of contamination from environmental activities and saline water ingress. The information from study could help in the planning, monitoring and management of potable water supply and development in deltaic coastal aquifer system.