Multi-stage Statistical Landslide Hazard Analysis: Earthquake-Induced Landslides

Abstract

Landslides are secondary or induced features, whose recurrence is controlled by the repetition of triggering events, such as earthquakes or heavy rainfall. This makes seismic landslide hazard analysis more complicated than ordinary seismic hazard analysis and requires multi-stage analysis. First, susceptibility analysis is utilized to divide a region into successive classes. Then, it is necessary to construct the relationship between the probability of landslide failure and earthquake intensity for each susceptibility class, or find the probability of failure surface using the susceptibility value and earthquake intensity as independent variables. Then, hazard analysis for the exceedance probability of earthquake intensity is performed. Finally, an analysis of the spatial probability of landslide failure under a certain return-period earthquake is drawn. This study uses data obtained from the Chi-Chi earthquake-induced landslides as input data set to perform the susceptibility analysis and probability of failure surface analysis. A regular probabilistic seismic hazard analysis is also conducted to map different return-period Arias intensities. Finally, a seismic landslide hazard map is provided.