On the application of Transient Electromagnetics (TEM) and DC-resistivity methods for groundwater level detection in the Cipatat karst area

Abstract

Due to mountainous morphology, meeting the freshwater demand for daily consumption in some villages in the Citatah karst area is problematic. Some water springs exist in some parts of the valley and slopes. The water flows through pipes connecting people’s houses by pumping it using electricity. To know the potential of the groundwater in the area, we conducted geophysical surveys in a test area close to known dig wells. These are Transient Electromagnetic (TEM) and DC-resistivity methods. TEM data were collected using an in–loop transmitter-receiver configuration with Temfast 48 devices with 5 m × 5 m and 10 m × 10 m wire loops. We acquired resistivity data using a 4-point light 10w IP device, producing resistivity and chargeability data. In this preliminary result, we show only resistivity distribution. We validated the processed TEM and resistivity data with the data from seven dig wells. Our results deliver good results. The resistivity data reveals low resistivity anomalies ranging from 26.5 Ωm to 58.5 Ωm. This low resistivity zone lies at 0.6 m – 1.45 m depth associated with groundwater level.