Proposal of probabilistic prediction method of travel distance in an earthquake-induced landslide

Abstract

In this study, we propose an empirical method for the probabilistic prediction of travel distance from landslide areas in an earthquake-induced landslide and then verify the applicability of the proposed method. In order to propose a probabilistic prediction method, we analyze the relationship between the travel distance (L) and landslide areas (A) in cases of landslides triggered by the Niigata-Chuetsu earthquake, the Iwate-Miyagi Nairiku earthquake, and the 2016 Kumamoto earthquake. We found that there was a power-law relationship between the measured travel distance and landslide area. This suggests that the travel distance might be predicted using the landslide area. However, the travel distances were largely scattered. Therefore, we propose a formula that can predict the probability of travel distance using F(r), which is the cumulative distribution function of the normal distribution of the ratio of the predicted and measured travel distance, Ri, since we find that it shows normal distribution in our three cases. In order to verify the proposed formula, we prepared training and test datasets for each case of the three earthquakes. Further we verified how much the probability of the travel distance in test datasets could be described by the proposed method.