我国小型水库数量众多，但安全状况差，且缺少有效的安全监测，管理水平落后，运行风险大。多年来水库安全鉴定主要以定性评价为主，对病险水库运行风险及其对下游的危害程度缺乏定量的判断。小型水库的运行风险多样，且不确定，不同风险之间往往相互影响、相互依存。本文以风险的不确定性作为灰色系统，将灰色理论和随机概率分析方法结合，建立功能函数，应用改进的一次二阶矩法把灰色—随机风险概率的计算转化为一般随机风险概率的计算，较好地量化了水库运行风险的不确定性。工程实例表明，计算结果对小型水库除险加固和安全运行具有良好的指导意义。

There are a number of small reservoirs in China, but they are in poor security situation with the lack of effective security monitoring and out-of-date management, therefore they have high risk in safe operation. Over the years, the security identification for reservoirs mainly focuses on qualitative evaluation, and the quantitative assessment of operation risk and impact on downstream properties of dangerous reservoirs are missing. The operation risk of small reservoirs varies and remains uncertain, and the uncertainty is often interactive and interdependent. In this paper, the uncertainty of operation risk was considered as a grey system, and the grey theory and stochastic probability method were combined to develop the power function. The modified first-order second-moment method can convert the calculation of grey-stochastic probability into the calculation of general stochastic probability, which can better quantify the uncertainty of operation risk of reservoirs. The case studies of application of the above method demonstrate that the calculation can provide good guidance for the safe operation and reinforcement of small reservoirs.

江西省水利厅科技资助项目（KT201207）