Multi-level Fuzzy Synthetic Evaluation For Dam Failure Based On Stochastic Simulation

Since the foundations of P.R. China in 1949, more than 3400 cases of dam breaks have occurred, which bring tremendous casualties and economic losses. According to the statistics, there are more than 80,000 reservoirs in china currently, of which more than 30,000 are seriously dangerous, and the hazard rate is about 40%. This brings a serious threat to the life and property downstream the dam. Therefore, assessing the consequences of dam break is very important in decreasing the level of risk management, to constitute the measures for flood prevention and relief, relief materials distribution and floodplain district.Previous researches of dam risk analysis focus on the evaluation of dam break consequences was briefly summarized at first, then analyzed and collated the components of dam break consequences. Secondly, life loss model, economic loss and social and environmental impact model were researched, and the comprehensive evaluation index factor of dam break consequences was determined. At last, the corresponding multi-level structure was established based on the previous study.Considering the complexity, uncertainty and ambiguity of the consequences of dam break, and the insufficiency existing data, as well as the interaction relationship between the evaluation results, the stochastic simulation method was combined with fuzzy synthetic evaluation method in the model. For which, stochastic simulation method was used to simulate the breach situation of the dam, and get the distributing of the losses, the fuzzy synthetic evaluation method was used to integrate all types of losses into one system to get the seriousness of the consequences of dam failure level. This is the establishment of dam break consequence multi-level fuzzy synthetic evaluation model based on stochastic simulation.Finally, the case study of Qingshan reservoir is presented to illustration. The model simulates the breach of Qingshan dam when suffered design flood with recurrence interval of ten thousand years with the initial level and dam breach factors were random variety, various types of losses were calculated and evaluated then, and at last get the result that it was a serious situation when Qingshan reservoir is breach, the result is coincidence to the reality.