Application of Geoelectric Method for Groundwater Exploration: Comparative Study of Wenner-Alpha and Wenner-Schlumberger Configurations in Way Manak, Tanggamus

Abstract

Groundwater is an important resource that needs to be managed sustainably, especially in areas with high dependence on groundwater such as Way Manak Village, Tanggamus Regency. This study aims to identify and map the distribution of aquifer layers in the Hulusimpang Formation using the Wenner-Alpha and Wenner-Schlumberger geoelectric resistivity configurations. Data acquisition was carried out on two intersecting lines of 235 meters with a distance between electrodes of 5 meters, and one vertical sounding point (VES). Data were processed using RES2DINV and IPI2Win software with a final RMS error value of 1.22–6.6%. The modeling results indicate a low resistivity zone (±8–22 Ωm) at a depth of 1–19 m which is interpreted as a shallow aquifer layer, associated with the tuffaceous sandstone and sandy tuff lithology of the Hulusimpang Formation. The Wenner-Schlumberger configuration shows better penetration capability and depth resolution than Wenner-Alpha, making it more effective in detecting vertical and lateral resistivity variations. Overall, the combination of these two configurations provides a more comprehensive picture of subsurface hydrogeology, and the results can be used as a reference in planning groundwater resource management in the research area.