Research On Flood Control Operating Decision Of Chaihe Reservoir Based On Net Rain Forecast Information

As an important strategic resource,water resources are the material basis and guarantee for the survival and development of human society.As we are located in the eastern end of the Eurasian continent,due to the influence of the East Asian monsoon climate,the spatial and temporal distribution of precipitation is not uniform.China is facing the problems of water resources distribution,such as "more summer and less winter,more South and less north".Especially in the past century,human activities have intensified frequently and climate change has been remarkable.The contradiction between water shortage and flood disasters has become increasingly prominent.The optimal allocation of water resources has also highlighted the more important social value.From the point of view of reservoir,flood forecasting and scientific operation play a vital role in the safety of reservoir operation and the optimal utilization of water resources.Reasonable operation and utilization of reservoirs will effectively alleviate the contradiction between water shortage and flood disaster,and further improve the utilization rate of water resources and even flood resources.Therefore,scientific prediction method and reasonable dispatching mode are the key to improve the utilization ratio of flood resources.As an important tributary on the left of the middle reaches of Liaohe River,The flood forecasting and dispatching of Chaihe Reservoir is of vital importance to the safety of flood discharge and the rational utilization of water resources in the basin.Based on the analysis of the basic situation of the river basin,this paper finds that the original flood forecasting method has insufficient accuracy and cannot meet the requirements of flood forecasting.The conventional operating method using the water level in front of the reservoir as the discriminative indicator to operate means that the precipitation runoff forecast information is not fully utilized,so the water use efficiency is not high.Therefore,this paper analyses the characteristics of rainstorm and flood in Chaihe River Basin,and chooses a more reliable flood forecasting scheme for Chaihe Reservoir.On this basis,the principle of flood forecasting and dispatching based on net rain forecasting information(i.e.real-time dynamic control scheme in flood season)is put forward for Chaihe Reservoir.The main research content is as follows:(1)The Dahuofang model and Liaoning index model suitable for flood prediction in Chaihe Reservoir are selected.Firstly,20 floods with consistency,reliability and representativeness are selected from the existing hydrological data of Chaihe River basin.Then,the Dahuofang model and Liaoning index model are used to simulate and forecast the floods,and the parameters of the model are calibrated by moment method,maximum likelihood method and artificial experience.The simulation results show that Liaoning index model is more accurate than Dahuofang model,and more suitable for different frequency flood forecasting in Chaihe River Basin,which improves the availability of flood forecasting results and the qualified rate of flood forecasting in Chaihe Reservoir.(2)In this paper,based on rainfall runoff(net rainfall)forecast information,the principle of flood control forecasting and dispatching of Chaihe Reservoir is studied.The purpose is to raise the starting water level in flood season and to improve the benefit on the premise of guaranteeing flood control capacity.The existing dispatching mode of Chaihe Reservoir is the conventional dispatching mode,and the discharging index of the reservoir is the water level of the reservoir.Based on the study of rainfall runoff forecast information,the flood prevention and dispatching mode of Chaihe Reservoir can be determined,which can advance the time of judging the magnitude of encountering flood and form a dynamic control scheme for the reservoir in flood season to ensure the safety of life and property of the reservoir and the protection targets on both sides of The results show that the forecasting and dispatching method based on net rain forecast information can significantly reduce the maximum water level of a single flood and improve the utilization rate of flood resources on the premise of guaranteeing flood control capacity..