Mapping groundwater potential zones in Cilongok Area, Banyumas, Central Java using 2D geoelectrical resistivity

Abstract

The aim of this study is to investigate the presence of potential aquifer layers that would be used as a source of clean water for residents in Cilongok sub-district. We conducted a ground water potential survey at two locations in the sub-district, i.e. Cikidang and Kalisari villages. At each location, geoelectric measurements were taken with the Wenner configuration and the horizontal distance of 900 meters, so that we can get the estimation of lithology layers that potentially store groundwater up to the depth of $\pm 100$ meters. Then the measurement result was processed by using Res2DInv software to get the 2D resistivity images of rock layers. Based on the resistivity estimation and observation of regional geological conditions in that area, then we conducted 2D interpretation about potential lithology layers that economically potential for water well drilling and to be utilized as a source of clean water for the residents. Based on the interpretation of lithology, it was known that the aquifer layer that has the potential as a source of clean water is a layer that consists of coarse and porous tuffs from volcanic eruption products that can easily drain groundwater on the average about 28 to 45 meters depth in Cikidang village and about 45 to 60 meters depth in Kalisari village.