Abstract:Wenchuan earthquakes have triggered a large number of geological disasters in Gansu Province, such as structural collapse and landslides. Based on studies of the distribution characteristics of earthquake-induced landslides during Wenchuan earthquake, we used a GIS-based weighted information model to evaluate the seismic landslides' risk in Wudu District and Wenxian County, Gansu Province. Results showed that:lithology types have a certain control effect on the distribution of seismic landslides, and most of the seismic landslides in the study area distribute and develop in both the extremely and relatively slide-prone strata, with a slope of 20°~50° and elevation of 1 000~2 000 m. With increasing seismic intensity, the density of seismic landslide disasters increases; about 70% of the landslides develop in the range of 10 km from the fault-fractured zone. Statistical analysis of the relationship between the risk classification results in the study area and the number and density of landslides showed that the evaluation results are highly accurate. In the elevated area, extremely dangerous areas are mainly distributed across catchment zones with strong surface runoff and frequent human engineering activity. In addition, the route of national highway G215 being along the extreme danger zone is obvious, so attention should be paid to the possibility of collapse and landslides in these areas. The high-risk area spreads along the extremely high-prone area, located on both sides of major rivers such as the Baishui and Bailong. Light risk and extremely light risk areas are relatively small, mainly distributed across high altitude areas with low intensity, poorly developed active faults, and weak human activity. Statistical analysis showed a total of about 780 thousand people in the study area potentially affected by the landslide hazard.