Risk Study Based On Reservoir Flood Control Forecast Operation Manner

As one of the major flood control engineering measures, reservoir plays an important role in national economic development, life and property safety and social stability. Rational reservoir flood prevention forecast operations may effectively handle or mitigate the main contradictions existed in reservoir flood operations, and may favor the effective integration of flood control and beneficial functions of reservoir. However, compared with the reservoir conventional operation, the implementation of flood control forecast operation mode will increase more risk factors and greater risk probability. So in reservoir flood control operation process, it is necessary to risk analysis. Also those provide technical support to promise the safe operation of the reservoir. In this dissertation, in terms of reservoir planning and design, determining way of reservoir flood control forecast operation rule, risk analysis methods of reservoir operation and risk factors are studied; and then the probability distribution of the random factors are simulated. Finally application of the instance is analyzed. The main research contents and results are as follows:(1) The methods and principles to select indicators of forecast operation rule are raised. And then corresponding net rainfall temporal distribution process to the reservoir design flood frequency is reviewed. In this paper, taking Huanren Reservoir as an example, a suitable flood control forecast operation rule is developed. In order to guarantee the safety of Huanren reservoir and its downstream, the rule has considered controlling the discharge by degrees, and adding certain safe leeway to the forecast indices. At the same time, to make sure the safety of the upstream, the rule takes the actual inflow and water level of Huanren reservoir as the auxiliary indices.(2) Because flood control reservoir operation mode may pose risk, systematically analyzing reservoir flood control operation risk problem, the risk characteristics and risk analysis methods of reservoir flood control operation are analyzed in detail. In this paper. taking Huanren Reservoir as an example, according to the definition of limited water level and dam safety which is brought forward by Professor Wang Bende, risk analysis of flood forecast error as single factor for flood control forecast operation is studied. That is to say. the risks of limited water level, risk rate of flood control forecast operation methods and maximum risk rate of dam safety are calculated and compared flood risk with the reservoir conventional operation.(3) The risk objectives of reservoir flood control operation and the risk definition are given in this paper. On the above basis, the flood forecast error, flood operation delay time and flood limitation water level are the main risk factors, and then an integrated risk analysis model also establishes considering the above-mentioned three kinds of uncertainties factors. For these factors, we use the corresponding simulation formula and develop Monte Carlo simulation program. In this dissertation, taking Huanren reservoir as an example, the risk ratio of flood control forecast operation is calculated considering the flood forecast error, flood operation delay time and flood limitation water level. The results show risk factors have great influence on big frequency floods and small little impact in small frequency floods.Lastly, the conclusions and problems need to be further studied are given at the end of the dissertation.