Risk Analysis Of Reservoir Flood-Prevention Based On The Combination Of Different Risk Factors

Flood disaster is happening with increasing frequency, which causes further losses, and the issues of water resource deficiency has seriously restricted the national economic development and the social stability. In this context, as a kind of unconventional water resources, flood has got the attention of people. As one of the major water conservancy engineering to achieve the flood resourcing, so in range of the flood operation risk, reservoir which setting the reasonable limited water level is the effective measures to raise the utilization rate of water resources.Based on the concept of risk analysis, this paper studies the reservoir’s risk analysis method of the flood-prevention. Taking Baiguishan reservoir for example, the model of risk analysis for reservoir operation based on the Monte-Carlo imitative technique is established, then calculating the risk ratio of different limited water level projects. The main research contents are as follows:(1) The risk objective is analyzed and the implementation procedure of risk analysis for reservoir flood control operation is studied, including risk identification, risk assessment, risk evaluation and risk decision.(2) Five major risk factors of the process of reservoir operation are discerned by fault tree analysis method, including the uncertainty of design flood-selection、flood-forecast error、flood-operation delay、storage capacity and discharge capacity of the reservoir, and the probability distribution of risk factors are analyzed.(3) Based on the Monte-Carlo technique, imitative formula of the five major factors about reservoir’s risk analysis of flood-prevention are presented, and the model of risk analysis for reservoir operation with different risk factors combination situation is established. Based on the actual condition of Baiguishan reservoir, getting design flood of the return period for 2000 years, 100 years, 50 years, 30 years, 20 years by the Same frequency amplification method, according to the adjustment schemes of limited water level(101m, 101.2m, 101.4m, 101.6m, 101.8m, 102m), the risk rate with different risk factors combination situation is calculated by flood routing, and then decide the reasonable limited water level schemes.Research shows: the limited water level of Baiguishan reservoir should be kept at a level of 101.8m.