Statistical seismic landslide hazard analysis: An example from Taiwan

Firstly, a susceptibility model is built using the 1999 Chi-Chi shallow landslides as a training data set and multivariate logistic regression as the analytical tool. This model is validated by using the 1998 Jueili earthquake-induced landslide data. Then, a probability-of-failure curve is established by comparing the Chi-Chi landslide data and the susceptibility values, after which the spatial probability of landslide occurrence is drawn. The temporal probability may be accounted for with the triggering factor (the hazard level of the Arias intensity), which was obtained through regular probabilistic seismic hazard analysis. Finally, the susceptibility model and the probability-of-failure curve are applied to the whole of Taiwan using the topographically corrected 475-year Arias intensity as a triggering factor to complete a seismic shallow-landslide probability map for ground-motions having a 475-year return period.