Geology and GIS – based flood vulnerability assesment in Kampung Laloh, Kuala Krai, Kelantan

The research mainly focuses on geological mapping in Kampung Laloh Kuala Krai, Kelantan. The total study area is approximately 28 km² using measurement dimension of 7km×4km, within the coordinate ranging from latitude 5° 22' 10" N to 5° 18' 30" N and longitude 102° 19' 10" E to 102° 21' 20" E. This area has a mountainous, hilly, and flat topography. Kampung Laloh, Kuala Krai require sufficient geological mapping, structure, and lithology data. The aim of the research is to create a geological map of the area in a scale of 1:25000. In order to accomplish the objective, the geological mapping component of this research relied on fieldwork inputs including collecting samples from fresh outcrops, identifying structural trends in rocks, and making other observations like geomorphological characteristics, drainage pattern, and others. The oldest sediments in the Eastern Belt of Peninsular Malaysia are predominantly Carboniferous and Permian clastic, limestones, and volcanics. Western Kuala Krai is composed of granite Stong Complex and the Gua Musang and Taku Schist rock formations. Moreover, dendritic and trellis drainage patterns were found in the research area. Dendritic patterns form on consistently strong bedrock, while parallel patterns formed where there is a slope and rectangular pattern exist in areas that have experienced faulting. All this field data, including petrographic studies, was processed in a GIS-based platform in order to create geological and other thematic maps. The lithology of the study area is phyllite, granite and meta mud rock. ArcGIS's Weighted Overlay Method (WOM) was used to create the flood hazard map by layering all relevant parameters based on the area's influences. Before applying the overlay technique, it was necessary to transform all parameters into raster data. The findings reveal that the flood hazard map was divided into five distinct classes based on the varying heights of the water which is very high, high, moderate, low, very low. As a conclusion, the local populace must be better informed and made aware of the risks associated with floods, therefore this is crucial. A major cause of flooding is the heavy rain that occurs naturally every year, especially during the northeast monsoon seasons of November through March. In addition, logging operations contribute to the rapid drainage of water into rivers, most notably the Sungai Kelantan.