Study on Risk Analysis of Large-scale Landslide

Teng-Chieh HSU, Yuan-Jung TSAI, Chjeng-Lun SHIEH and Jen-Yuen CHENG

With the implement of mitigation work of large-scale landslide, hundreds of potential large-scale landslide areas were identified in Taiwan since 2010. The topographical features, geological conditions and situation of property and residents were used to evaluate the risk for each potential large-scale landslide in the first stage. Therefore, a lot of countermeasures and monitoring systems were setup to reduce the risk of potential large-scale landslide. However, the approach of risk assessment in the first stage did not consider risk distribution in a regional area, so that the effect of mitigation work and land-use management cannot be estimated. In this study, we present a risk assessment approach to evaluate the risk of large-scale landslide and the effect of the mitigation work. The risk is the probability of potential loss. In this study, we define the risk is the function of hazard, exposure and vulnerability. Hazard is considering the deposition depth and movement velocity. Exposure is considering the land use (building, road, agricultural land, forest), which is exposed in the hazard area. Vulnerability is considering the relationship between land use, hazard, and loss curve. Furthermore, this approach considers the effect of mitigation work such as land-use management and sabo work. The result shows that, the potential loss can be well quantify with the approach. Furthermore, the effect of the mitigation work, such as land use managements and sabo works, can be also well described in this approach.

2018/1 183-190