Geological mapping in area Lojing and investigation of seawater intrusion of Sungai Pinang aquifer at Tumpat by geophysical and hydrochemistry

The present research is focused on geological mapping and seawater intrusion studies in parts of Lojing and Tumpat area respectively. The main objective of this research is to update geological rock units and produce map on scale of 1:25000 and investigate sea water intrusion in Sungai Pinang coastal aquifers in Tumpat. The methodology was applied for geological mapping based on fieldwork inputs including collection of samples from outcrop, recording structural trends in rocks and other field observation such as geomorphological features, drainage pattern etc. All these field related data processed in GIS based platform including the petrographic studies to generate geological and other thematic maps. For seawater intrusion studies Electrical Resistivity Imaging (ERI) survey were conducted and resistivity data processed using RESD2DINV software to obtain two- dimensional 2D resistivity profile and as well as geochemical method were also applied to investigate seawater intrusion. Insitu chemical parameter includes pH, turbidity, total dissolved solid (TDS), salinity, total suspended (TSS), electrical conductivity (EC). In addition few chemical parameters includes chloride, sodium, manganese, potassium, copper and iron were also analysed from selected shallow groundwater wells. Geologically the study area mainly consist schist and mudstone rock units. Based on the resistivity data which provided clear view as seawater intruded zoned into groundwater in all the lines approximately 50 to 70m. In addition the hydrochemical results shows that sample T5 contain sea water intrusion at shallow level. It is recommended to overcome this problem could be regular quality monitoring as well as control the pumping of groundwater.