Assessment of river bank erosion at Kilim River, Langkawi using geospatial technique

Abstract

In Malaysia, the reduction of mangrove area is very serious which urges government to take appropriate and stern action to solve this problem. The study area is in Kilim River, Langkawi, one of the most attractive tourist spots in Malaysia. This area is now under the threat of significant river bank erosion caused by intensification of tourism that visited this wonderful mangrove area. In this study, geospatial technique is used for assessment of river bank of Kilim River, Langkawi, Kedah. It is one of the main tourist attraction in Malaysia with UNESCO recognition since 2007 as Kilim Geoforest Park. It is well known as nature reserve that consist of various amazing flora and fauna in the mangrove area. In this area, the tourists hired boat to visit the surrounding area. However, there are too many boats used, many trips and uncontrolled speed boat that caused river erosion. The aim of this research is to assess river bank erosion using remote sensing image and GIS tools in analyzing the impact that caused river erosion by the tourist speed boat. In order to determine the rate of changes of river erosion occurred along the river bank, Digital Shoreline Analysis System (DSAS) software is used in this research which highlight two main statistical analysis of Net Shoreline Movement (NSM) and End Point Rate (EPR) of both sides of the river bank. The output of this study shows significant changes of river erosion and also accretion along the river bank which can be seen by the extraction or river line. Also in this study, the migration of mangrove trees is also examined. In conclusion, the impact towards the migration of mangrove trees and riverbank erosion can be identified and predicted based on several epochs of observation using remotely sensed data.