Risk assessment of seismic landslides based on analysis of historical earthquake disaster characteristics

Abstract

Risk assessment of seismic landslides in potential earthquake zones is important for construction in mountainous areas. To present a new method for conducting risk assessment of landslides, data of 720 landslides caused by the Ludian Ms6.5 earthquake, which occurred in 2014, are taken as a sample, and five impact factors are selected as risk assessment indexes; these factors include the slope, slope direction, elevation, strata lithology, and peak ground acceleration. Fractal theory and the result of the landslide distribution analysis of the Ludian earthquake are adopted to calculate the weight of each impact factor. The proposed risk assessment method is established by calculating the landslide distribution density. Under an assumed earthquake, the method is used for conducting risk assessment in the Dayong Expressway region; the topography and geology of this region are very similar to those of the Ludian County. The landslide risk zoning in the region can be obtained using the K-means cluster method to classify the risk level after the assignment of the landslide risk index. The result shows that a 2.25-km route of the Dayong Expressway has the highest risk of geological disasters with an occurrence probability of 1.1% considering the influence of the Chenghai fault. The assessment results can provide a scientific basis for disaster prevention in the Dayong Expressway area.