Identification of aquifers using geoelectric mapping and souding methods in Tanah Merah village, North Samarinda district

The need for raw water in Tanah Merah Village, North Samarinda District can only be met by groundwater whose the position of aquifer has not been known for sure until now. The purpose of this study was to identify the existence and type of aquifers. This research is carried out in Serayu-Citanduy Road section. This research was conducted by morphological, geological, geoelectric mapping and sounding. Geoelectric measurement data are then interpreted to determine the location and type of aquifer and also compared to data from morphological and geological observations. The results of the mapping data show that the layer indicated as an aquifer is sandstone with the resistivity above 100 Ωm that stretching to a depth of 36.9 meters below the surface. The layer indicated as aquiclud is claystone with resistivity below 80.3 Ωm. Meanwhile, the results of sounding data shows two types of aquifers consisting of unconfined aquifer at a depth of 5.24 meters and forming a groundwater basin to a depth of 200 meters with a resistivity of 110-668 Ωm and confined aquifers at depths below 100 meters with a resistivity of 138.4-357.4 Ωm. This suggests that there is an interrelated relationship between data mapping and data sounding.