Landslides often occur in the mountain areas of Taiwan, which are affected strongly by geography, environment and climate. Especially, the slope failure induced by heavily rain is frequent. Because of limited land and crowded population, the inhabitants of the mountain areas and traffic facilities fail to avoid thoroughly the landslide potential area which results in serious damages. Thus, the slope stability and risk evaluation are important issues for land development and use in the mountain areas of Taiwan. In this paper, the Lshan hot spring district is taken as a case study and used to evaluate the landslide risk. First, the limit equilibrium method and reliability index are used to calculate the landslide probability of the top slope above the hot spring district. Next, the road and structure losses are estimated based on the field investigation as the landslide will happen in the future. Finally, the landslide probability and loss calculation are integrated to express the landside risk.
It has been an unavoidable tendency towards the development and use of hillside land in Taiwan because of limited plain land and crowded population. Subject to geography, environment and climate, however, the occurrences of several slope hazards are frequent, especially the rain-induced landslide in the colluvium and weathered rock stratum. It is rather unfortunate that the residence locations and traffic facilities fail to keep away form the landslide districts, which often results in serious damages. The landslide induced by the Morakot typhoon, which occurred in Jiaxian township, Taiwan in August, 2009, is a significant example. Thus, it is deeply concerned for evaluating the slope stability and landslide risk in the process of land development and use. The Lushan hot spring district located in Nantou, Taiwan is used as an example for evaluating the slope stability and landslide risk.
