Digital terrain analysis of wide-area landslide hazards based on multisource data
The geological disasters of shallow surface landslides are significantly affected by the terrain and soil moisture content,and they generally have obvious deformation characteristics. This paper first employed wide-area interferometric synthetic aperture radar(InSAR) to identify abnormal deformation areas,and adopted airborne light detection and ranging (LiDAR) to collect point cloud data of not less than 20 points per square meter (pts/m2) on the ground. The point cloud was filtered and classified to generate the digital elevation model of filtered cover. The parameterized terrain and geomorphological features were obtained,including slope height,slope,aspect,and slope shape.Then,high-resolution images were employed to help extract suspected areas of landslide hazards for on-site verification. The results show that the height of landslide hazards is concentrated at 10-20 m,and the slope is distributed at 25°-45°. The northeast straight line and the stepped slope are the main,with well-developed vegetation. The use of LiDAR can accurately detect the slope surface morphological characteristics of forests with landslide hazards,which provides an engineering reference value for early identification of geological hazards in vegetation developed areas.
light detection and ranging (LiDAR)landslide hazardssloperemote sensing imagesdigital elevation model