中文摘要：

水利水电建设在许多河流上已形成梯级开发的格局，梯级库群既是国民经济的支柱产业，又是可能给人类社会带来灾难性后果的高风险源。因此，研究梯级库群系统的整体破坏风险显得尤为重要。本文在使用模糊隶属度函数计算单个水库漫顶失效概率的基础上，运用系统工程中层次分析法的相关知识，建立了梯级库群失效的层次分析模型，构造相应的判断矩阵来计算流域中各水库的综合权重，通过对比选用了k／N系统可靠度模型对整个梯级库群进行分析，最终综合计算出含权重因子的梯级库群系统的整体失效概率，与传统k／N系统可靠度模型计算出的梯级库群失效概率相比，本文所得的梯级库群系统失效概率更为合理，可为梯级库群的安全分析及优化设计提供一定的参考。

英文摘要：

Cascade reservoirs have been developed in many rivers, which become not only a pillar industry in the national economy, but also some potential high risk sources that pose a direct threat to human society. Thus, it is important to study the overall failure risk of the cascade reservoirs. In this paper, on the basis of the theory of fuzzy mathematics, semi-ascending gamma distribution is used as the membership function in calculating the fuzzy failure probability of overtopping for a single concrete dam. Based on this, a hierarchical analysis model for the failure of the cascade reservoirs has been established through the Ana- lytic Hierarchy Process （AHP）. The corresponding judgment matrix was constructed, and the comprehensive weight of each reservoir in the river basin was calculated. At last, the global failure risk of the cascade reservoirs system was calculated by using the k/N system reliability model of the reliability theory. Com- pared with the global failure probability from the traditional calculation of k/N system, the result of AHP method is closer to the actual situation. This study provides certain reference for safety analysis and optimi- zation design of the cascade reservoirs system.