THE APPLICATION OF LIDAR DERIVED HIGH RESOLUTION DIGITAL TERRAIN MODELS (HRDTMs) FOR THE LANDSLIDE DETECTION AND INVENTORY MAPPING OF CAMERON HIGHLANDS, MALAYSIA

摘要

The purpose of this paper is to utilise the capability of LIDAR derived High Resolution Digital Terrain Models (HRDTMs) and the interactive view of 3D visualization of GIS for the landslide detection and inventory mapping in Cameron Highlands, Malaysia. Airborne Laser Scanning (ALS) point cloud data with surface horizontal accuracy of 30 cm and vertical accuracy of 15 cm was used to generate HRDTMs of 0.5 m grid using IDW surface interpolation technique. In addition shaded relief map with altitude angle of the light source 40° and azimuth angle of illumination 310°, contour line map at 1 m interval as well as slope map was produced from the HRDTMs. The orthophotos with 7 cm spatial resolution was draped over the HRDTMs to create 3D perspective view. From the study, landslides features such as main scarp, zone of depletion and zone of accumulation are clearly visible and easy to delineate. Most new landslides polygons are found in forested area and agricultural area compared to the existing historical landslide data which is along roads and rivers. The results obtained from this study is to demonstrate the capability of utilising HRDTMs and 3D visualization in landslide mapping interpretation. This study is useful as it is part of validation process of landslide inventory mapping and for future planning of slope management, sustainable land use planning and development by related agencies and local authorities in Malaysia.