Evaluating Susceptibility of Debris Flow Hazard using Multivariate Statistical Analysis in Hualien County

Abstract

Taiwan was recently ravaged by frequent natural disasters. The typhoons and heavy rainfall triggered landslides, often causing incalculable damage to human's life or properties. In this study, we evaluated the susceptibility of debris flow hazard of 160 potential debris flow creeks in Hualien County by using multivariate statistical analysis. Five categories of topographic factors, including watershed form, slope, height, aspect and landslide, were used as independent variables and debris flow inventory as dependent variable. By using principal component and correlation analysis, 10 topographic factors are correlated with dependent variable at 85% significance level. Then, we evaluated susceptibility of debris flow from the 10 topographic factors by using logistic regression and verified by the classification error matrix, ROC curve and debris flow inventory. The study has established debris flow susceptibility maps and method of debris flow hazard assessment for debris flow prevention and risk management.