Many dams have been constructed around the world. Compared with the potential losses of life and economy, the environmental impacts caused by dam breach were less analyzed. As a systematic theory, the set pair analysis method deals with both the certainty and uncertainty of a system or process as a whole. But when dealing with the analysis of environmental impacts with obvious uncertainty, the fuzziness feature of the indices was not considered comprehensively. Hence, this paper introduced the connection degree of set pair analysis in five grades, and the cloud model-based weight calculation method to improve the evaluation. The proposed method was applied to the case study of Qianping Reservoir, Henan Province, China, showing that the comprehensive environmental impacts caused by the potential dam breach were medium. The results of the study indicate that the proposed method is applicative and provides reliability for environmental impacts evaluation of dam breach.

世界各地都建造了许多水坝。与可能造成的生命和经济损失相比，对因大坝破坏造成的环境影响的分析较少。作为系统理论，集对分析方法既要处理整个系统或过程的确定性又要处理不确定性。但是，在处理具有明显不确定性的环境影响分析时，并未综合考虑指标的模糊性。因此，本文介绍了五个等级的集合对分析的连接度，以及基于云模型的权重计算方法以提高评估的准确性。将该方法应用于河南省钱坪水库的案例研究，结果表明，潜在的大坝破坏对环境的综合影响中等。