Landslide data mosaicking based on an airborne laser point cloud and multi-beam sonar images

Abstract

Landslides are one of the most disastrous geological hazards in southwestern China. Once a landslide becomes unstable, it threatens the lives and safety of local residents. However, empirical studies on landslides have predominantly focused on landslides that occur on land. To this end, we aim to investigate ashore and underwater landslide data synchronously. This study proposes an optimized mosaicking method for ashore and underwater landslide data. This method fuses an airborne laser point cloud with multi-beam depth sounder images. Owing to their relatively high efficiency and large coverage area, airborne laser measurement systems are suitable for emergency investigations of landslides. Based on the airborne laser point cloud, the traversal of the point with the lowest elevation value in the point set can be used to perform rapid extraction of the crude channel boundaries. Further meticulous extraction of the channel boundaries is then implemented using the probability mean value optimization method. In addition, synthesis of the integrated ashore and underwater landslide data angle is realized using the spatial guide line between the channel boundaries and the underwater multi-beam sonar images. A landslide located on the right bank of the middle reaches of the Yalong River is selected as a case study to demonstrate that the proposed method has higher precision than traditional methods. The experimental results show that the mosaicking method in this study can meet the basic needs of landslide modeling and provide a basis for qualitative and quantitative analysis and stability prediction of landslides.