Landslide is a common geological hazard in reservoir areas and may cause great damage to local residents’ life and property. It is widely accepted that rainfall and periodic variation of water level are the two main factors triggering reservoir landslides. In this study, the Bazimen landslide located in the Three Gorges Reservoir (TGR) was back-analyzed as a case study. Based on the statistical features of the last 3-year monitored data and field instrumentations, the landslide susceptibility in an annual cycle and four representative periods was investigated via the deterministic and probabilistic analysis, respectively. The results indicate that the fluctuation of the reservoir water level plays a pivotal role in inducing slope failures, for the minimum stability coefficient occurs at the rapid decline period of water level. The probabilistic analysis results reveal that the initial sliding surface is the most important area influencing the occurrence of landslide, compared with other parts in the landslide. The seepage calculations from probabilistic analysis imply that rainfall is a relatively inferior factor affecting slope stability. This study aims to provide preliminary guidance on risk management and early warning in the TGR area.

滑坡是水库地区常见的地质灾害，可能会严重损害当地居民的生命和财产。降雨和水位的周期性变化是触发水库滑坡的两个主要因素，这一点已被广泛接受。在本研究中，作为案例研究，对位于三峡水库（TGR）的Bazimen滑坡进行了反分析。根据最近三年监测数据和现场仪器的统计特征，分别通过确定性和概率分析研究了一年周期和四个代表性时期的滑坡敏感性。结果表明，水库水位的波动在诱发边坡破坏中起着关键作用，因为最小稳定系数出现在水位快速下降时期。概率分析结果表明，与滑坡的其他部分相比，初始滑动面是影响滑坡发生最重要的区域。概率分析的渗流计算表明，降雨是影响边坡稳定性的相对较差的因素。本研究旨在为TGR地区的风险管理和预警提供初步指导。