Risk Analysis of Individual Landslide in the Three Gorges Reservoir

Abstract

Landslide along the reservoir bank with secondary surges can form a hazard chain, causing greater risk than the landslide itself. Taking Zhaoshuling landslide in the Three Gorges reservoir as an example, the methodology of landslide risk analysis, including risk identification, probability, vulnerability and hazard consequence are discussed in this paper. The landslide risk is identified by field inventory firstly. The annual probability is calculated by Monte Carlo method according to landslide geology environment. The hazard intensity, landslide velocity and volume moving into water are assessed by Newton’s Second Law and kinematic equation. Based on the results, landslide initial surge height and propagation distance, which are important references for surge influence area, are calculated by Pan’s method. In this area, elements at risk are identified and the vulnerability is assessed for buildings and persons. Based on the result of hazard and vulnerability, economic and people risk assessment is made. It shows that landslide may cause about 15.447 million RMB annul economic risk and 4.721 people risk with annual probability 0.07556, and about 7.008 million RMB annual economic risk and 10.04 people risk with annual probability 0.03406. These findings can help local authorities to manage landslide risk and make emergency measures.