Groundwater Potential Mapping Using Geophysical Techniques: a Case Study in Hosanna Area, Western Margin of The Central Main Ethiopian Rift, Ethiopia

Abstract

Esubalew Yehualaw, Tigistu Haile and Wubamlak Nigusse

In this study, Vertical Electrical Sounding (VES) and magnetic methods are applied for mapping the groundwater potential and aquifer system in the Gode area, the western margin of Central Main Ethiopian Rift. The VES is used to map the depth to potential aquifer zone of the groundwater and its distribution over the area, whereas, the magnetic survey is applied to delineate contact between lithologic units and geological structures. A total of 12 VES data points and more than 400 magnetic data points at about 10m station intervals along seven profiles are collected, processed and analyzed. Our results from interpretation of the VES data, geoelectric sections, and 2D magnetic modeling results respectively revealed the vertical stratification of the subsurface geoelectric layers and the presence of subsurface weak zones, which control the groundwater flow and storage system where the potential aquifer in the area obtained at a depth range from 45m to 92m. Overall, areas in the neighborhood of four VES points, i.e.VES-2, -3, -10, and -11, show good water-bearing zones in the study area associated with the highly weathered/fractured ignimbrite and pumice layers.

PDF