Geological mapping and potential seawater intrusion in Kelantan using electrical resistivity imaging method

The geophysical analysis of groundwater exploration mainly focused on Kota Bharu coastal area. The study area is located in Kota Bharu with the centre coordinate of N 6°12'65.980", E 102°33'06.340". The study area covers from the bottom part of Pengkalan Chepa to the upper part of Bachok. The study area covers a 25 km2 of box. The study area has settlements scattered all over which indicates the annual withdrawal of groundwater is high. The objectives of the research are to produce an updated map of Lojing, Gua Musang, and to perform the geophysical analysis of seawater intrusion in the study area. The geology of the study area in Lojing was determined by carrying out ground mapping to construct geological map. The study area has 4 types of lithology which are mostly mudstone, followed by marble, slate and feldsphatic wacke. New geological map produced by ArcGIS software based on the geological data. In order to carry out geophysical analysis, three places with high human settlements were chosen and conducted electrical resistivity imaging technique and 2-D resistivity profiles were produced. Sea water intrusion evaluated by using the result obtained from the analysis of resistivity profile. All three results show intrusion of seawater in the second aquifer where the depth is more than 50 metres. The level of intrusion indicates that the study area is experiencing early stages of seawater intrusion. In future, scientists are recommended to utilize increasingly modem research centre instruments to build the exactness and accuracy of the after effect of the investigation.