A landslide volume calculation method based on LiDAR topography and slip surface reconstruction: A case study of Deda ancient landslide in Batang County of Sichuan Province

Because of its suddenly occurrence and rapid movement, the landslide could do great harm to the society and human life. Because the damage caused by landslide increases with the increase of landslide scale, the accurate calculation of landslide volume is extremely important for the disaster prevention and control projects, and the disaster prevention and mitigation risk evaluation. At present, the commonly used methods for landslide volume calculation mainly include field measurement method, geometric method, numerical simulation method, and DEM method, etc., but there are some certain limitations and poor accuracy of landslide volume calculation results in some of those methods. Therefore, a landslide volume calculation method was proposed, which is based on the high-precision LiDAR terrain and sliding surface reconstruction and named LS-Drill_Volume. The Deda ancient landslide, distributed in Batang County of Sichuan Province, was taken as an example for the LS-Drill_Volume study. The airborne LiDAR scanning method was used to obtain the topographic data of Deda ancient landslide, the landslide boundary points and drill data were interpolated by Kriging interpolation method, and then the sliding surface was reconstructed. Based on the obtained the elevation of the sliding surface, by means of ArcGIS software, the landslide volume was finally calculated by filling and excavation. The calculating results show that the volume of Deda ancient landslide is 1259×10⁴ m³, of which the volume of Deda Ⅰ landslide section is 613×10⁴ m³, and the volume of landslide Ⅱ section is 646×10⁴ m³. Compared with the field measurement method, the volume calculation accuracy is improved by 20.8%, 21.4% and 20.2%, respectively. Compared with the existing volume measurement methods, this method can provide more accurate volume of landslide, so as to provide more reliable basis for landslide evaluation and prevention engineering.