Geological Mapping and Application of Electrical Resistivity Imaging in Evaluating of Groundwater Sources: A Case Study in Kg. Lepan Jaya, Gua Musang

This study was focus about geology and groundwater sources in study area in Kampung Lepan Jaya, Gua Musang. The objectives of this study are to update the geological map of study area on a scale l: 25,000 and to investigate groundwater sources by using electrical resistivity imaging technique. Geological mapping was conducted in order to collect surface geological data such as the rock distribution, structural geology and geomorphology. Rock samples were collected for petrography analysis, mainly for identification of the rock types. Geological map shows the locations where rocks are exposed at the Earth’s surface. The geology of the area is covered by limestone, slate, ruff, mudstone and sandstone. Besides, geological map also shows geological feature such as faults and strike dip of rock. The study area is covered by hilly and mountainous. The drainage patterns are trellis and dendritic patter. Electrical resistivity imaging technique was chosen for investigate groundwater source zone instead others geophysical techniques. The three electrical resistivity lines were selected at different lithology’s which are limestone and mudstone. Wenner and Wenner-Schlumberger array configuration were used with electrode spacing distance was 5 m and the length of 200 m. The resistivity imaging measurement was carried out using an ABEM Tetrameter LS 1, which electrodes were arranged in a straight line with constant spacing and connected to ABEM LUND cable. The resistivity data were processed by using RESZDINV and the result displayed as pseudo section. The 2D profile showed the zone of alluvium and hard rock zone. The lower resistivity values are indicated groundwater source zone. The results showed that Line 2 has groundwater sources zone with resistivity value is ranging from 10 Q.m to 100 Q.m.