Groundwater Detection Using Resistivity at Nubutautau Village in Viti Levu in Fiji

Abstract

A geophysical technique termed Electrical Resistivity Tomography was applied to identify potential groundwater-bearing zones around Nubutautau village within Viti Levu Island of Fiji. Apparent resistivity data of the subsurface were collected through the electrode assembly along survey lines by injecting current into the subsurface using the ABEM Terrameter LS2. True resistivity data were simulated using the Res2DINVx64 software to produce the final electrical resistivity profiles through an iterative process. Analysis of the resulting modelled profiles revealed the presence of two potential groundwater-bearing zones as potential targets for future drilling. The two targets indicated the presence of potentially saturated vertical fractures through which infiltrating rainwater percolates through the volcanic rock towards a deeper basal aquifer. The identification of the two potential targets demonstrated the great potential of this geophysical technique to effectively inform drilling operations through an evidence-based approach to increase the successful delivery of water security interventions in remote, drought-prone communities of the Pacific.