Large-scale assessment of landslide hazard, vulnerability and risk in China

Landslides (generally including debris flows) seriously threaten life and property. Studies on landslide risk are of great significance for regional disaster prevention and mitigation. In this study, the grid of 1km x1km was selected as the assessment unit to exhibit the spatial distribution of landslide risk in China. With the support of Geographic Information System (GIS) technique, the combined model of certainty factor model (CF) and logistic regression model (LR) was applied to assess the landslide hazard, Liu's method was used to evaluate the landslide vulnerability, and the product of hazard multiplied by vulnerability was used to represent the landslide risk. The spatial patterns of the hazard, vulnerability and risk of landslides were displayed on the national scale of China. The results indicated that the high hazard zones are commonly distributed in the south of Yangtze River, especially the very high hazard zones are concentrated in the southwest of China. The high vulnerability zones are mainly distributed in the eastern coastal cities with developed economy and dense population. The distributional pattern of landslide risk is approximately divided by Heihe-Tengchong population density line. The west of the line is mainly distributed low risk areas; whereas the east of the line contains moderate and high risk areas. The classes of very low, low, moderate, high and very high risk areas account for 40.51%, 18.34%, 33.86%, 7.28% and 0.01% of the total area respectively. The macro-scale regional assessment is needed in China, which may benefit the top design of landslide risk reduction and territorial functional zoning.