Abstract:
On December 18, 2023, at 23:59, a magnitude Ms6.2 earthquake occurred in Jishishan County, Gansu province, resulting in significant casualties and triggering numerous secondary geological disasters such as landslides and collapses. Utilizing high-resolution satellite imagery from before and after the earthquake, this study employs a MaxEnt model, constructed with visually interpreted disaster points and a set of impact factor characteristics, to assess the post-earthquake landslide hazard post-earthquake landslide hazard. The research conclusions are as follows: 1) Earthquake-induced landslide disasters are predominantly distributed within sunny slopes at elevations of
1800−
2300 m and slope gradient of 20−25°, extensively across areas 1.5 km from roads, 1.7 km from fault zones, and within 5 km of the earthquake’s epicenter. The majority of the disasters occurred in cropland and loam areas with higher population density in the earthquake region. 2) The main influencing factors for earthquake-induced landslides determined by factor contribution rates, permutation importance, test benefit values, AUC values, and regularization training gain value were comprehensively determined as follows: Distance from the fault zone, Elevation, and Population density; 3) Based on the constructed MaxEnt model, it is found that there is a good consistency between the extremely high and high-risk areas of landslide disasters in the earthquake zone and the seismic intensity. Among them, the extremely high and high-risk areas are mainly distributed in the intensity VIII zone, with an area of 5.368km
2, accounting for 77.82% of the total area of the extremely high and high-risk zones. The low and very low-risk areas are mainly distributed in the intensity VI and VII zones, accounting for 92.80% of the total area of the study region. This study constructs the MaxEnt model based on the importance analysis of impact factors to evaluate the landslide hazard in the earthquake area, providing references for post-disaster reconstruction in the earthquake zone.