Research On Optimal Flood Control Operation Of Zihong Reservoir In Shanxi Province

The special landform and water resources distribution characteristics of China determine the current situation of frequent floods in China,and the uneven distribution of water resources makes the contradiction between supply and demand prominent.The shortage of water resources has become one of the major issues affecting the development of our productive forces.In order to alleviate the contradiction between the supply and demand of water resources and reduce the losses caused by floods,rational scheduling of flood water resources will be a key measure to solve the problem.Reservoir flood control is one of the non-engineering measures of reservoir operation management.It can play an important role in solving flood control safety problems,improving the utilization efficiency of flood water resources,and increasing flood control benefits of reservoirs.Therefore,it is of great practical significance to study a reasonable reservoir flood control theory and make full use of flood resources through the regulation of runoff process.At present,there are two types of commonly used dispatching methods for reservoirs,which are conventional scheduling methods.In the other case,when the reservoir encounters a large flood,it is advisable to adopt a forecasting and scheduling method.Due to the constraints of economic and technological development,the study of flood forecasting and scheduling needs to be further developed.Zihong Reservoir is one of the reservoirs of the Shanxi Dashui Network Project.The flood control of the flood season can not only ensure the flood control safety of the reservoir upstream and downstream,but also make great contribution to the flood control and disaster reduction of the entire large-scale water network.Based on the study of the characteristics of the Zihong reservoir basin,this paper analyzes the current status of reservoir flood control,proposes the flood forecasting method of Zihong reservoir,establishes different flood control models,and conducts reservoir flood control research.The main research contents and results are as follows:(1)Establish flood forecast model of Zihong Reservoir.First,the data of rainfall and river inflow were analyzed and the watershed was divided into units.Then,the double-super model was used to simulate and predict the historical flood of Zihong Reservoir.The selected 10 floods are simulated.The simulation results show that the simulation error of the peak discharge in 2003 is the largest with a maximum value of-18.7.The simulation error of the peak discharge in 1997 is the smallest with a minimum value of-3.0.Although the simulation error of each flood is different,but the peak flow error is within 20%,the peak error is up to 2h,are in line with regulatory requirements.Therefore,the double-super model can be used to simulate the flood of Zihong reservoir flood,and the peak and peak time forecast is more accurate.(2)Four-submerge flood reservoir optimization scheduling model was established.The four models are the dam safety scheduling model,the maximum peak clipping model,the minimum water loss model,and the minimum flood loss model.By studying the different flood prevention targets of Zihong Reservoir,different targets are established by different targets.The establishment of the scheduling model has laid a theoretical foundation for the rational operation of the water resources of Zihong Reservoir,and can effectively increase the flood control benefits of the reservoir.The results show that the improved particle swarm optimization algorithm is superior to the stepwise optimization algorithm.The improved particle swarm algorithm has a better peak clipping effect and a lower maximum water level in front of the dam,which helps to reduce the flood peak and ensure the safety of the dam.(3)Improved particle swarm optimization algorithm.The nonlinear descending formula with a control factor is used to improve the parameters of the particle swarm algorithm—inertia weight ?.The chaos theory was used to optimize the initial feasible solution of the particle swarm optimization algorithm and increase the reliability of the initial solution.The scheduling results show that the improved particle swarm algorithm is superior to the stepwise optimization algorithm in scheduling results,and can improve the algorithm's search ability and avoid the algorithm falling into the local optimal solution.(4)Establishing the flood control optimized dispatching system of Zihong Reservoir.According to the general situation and basic data of Zihong reservoir basin,the software development is completed with VB6.0.The improved particle swarm optimization algorithm and reservoir flood control scheduling model are written into corresponding programs.The specific interface is divided into three parts including basic reservoir information and optimized scheduling model.Library and result output.Finally,a friendly human-computer interaction interface is generated to provide reservoir operators with the basis for decision-making of reservoir scheduling.Reservoir flood control operation is one of the effective methods for flood control and disaster reduction and increasing the profitability of reservoirs,and plays an important role in reducing flood disasters.However,due to a large number of uncertainties in reservoir flood control scheduling,such as meteorology and hydrology,the risks brought about by these uncertainties need further study.