Study on spatial distribution of earthquake-induced landslide in densely populated area of the Luding 9.5 earthquake

On September 5, 2022, an earthquake with Ms6.8 occurred in Luding County, Ganzi, Sichuan Province, causing heavy casualties and economic and property losses. Because the earthquake-stricken areas are mostly mountainous and canyon landforms and dense vegetation, it is difficult to investigate geological disasters on the artificial ground, and it is difficult to accurately identify the landslide boundary under high vegetation coverage by satellite images. Therefore, in order to deeply understand the spatial distribution characteristics of this earthquake-induced landslide, this paper provides a visual interpretation of the coseismic landslide based on the 0.2m resolution optical image (DOM) obtained after the earthquake, and then the boundary of the coseismic landslide under the vegetation layer is corrected by using the digital elevation model (DEM) with a resolution of 0.5m, at the same time, the potential earthquake landslide under the vegetation layer is interpreted, combined with the field investigation, 9248 landslides induced by this earthquake are finally obtained, with a total area of about 45.57km2. On this basis, the relationship between the geological background such as topography, geological structure and seismic factors and the distribution of coseismic landslides is analyzed, aiming at providing an important basis for the investigation of hidden dangers of geological disasters in disaster areas, disaster assessment and site selection for post-disaster resettlement, as well as providing an important foundation and guarantee for post-disaster reconstruction and geological disaster prevention.