Research On Water Diversion And Water Supply Of Inter-basin Transfer Project By Coupling Medium And Long-term Runoff Forecast

The uneven distribution of water resources and the rapid social and economic development have led to a prominent contradiction between the supply and demand of water resources in my country.The construction of inter-basin water transfer projects across river basins is an important engineering measure to solve this problem.Scientific and reasonable trans-basin water diversion rules determine the efficiency of inter-basin water transfer projects and are the key to give full play to the role of trans-basin water diversion projects.How to effectively use forecast information to formulate water diversion rules and ensure the effectiveness of water diversion is a key issue that needs to be solved urgently.Therefore,this paper selects the Biliuhe-Dahuofang inter-basin water transfer projects as the research object.First,it studies the screening method of mid-and long-term runoff forecast factors to improve the forecast accuracy;on this basis,the optimal water diversion operation rules are formulated by coupling the forecast information;finally,the analysis The impact of different forecast accuracy on water diversion efficiency and water supply benefit.The main research contents and results are as follows:(1)Analyze the mid-and long-term runoff forecast of the Biliuhe Reservoir.In view of the fact that the number of candidate factors in the medium and long-term runoff forecast is significantly larger than the data sample,the stability selection method is used to screen the predictors of the runoff forecast.On this basis,based on the BP neural network model,the monthly runoff forecast model of the Biliuhe Reservoir is established,Forecast model of total runoff during the flood season at different times.The results show that,compared with the factor screening method based on mutual information,the forecast accuracy of the model established by the factor screening method based on stability selection is higher.(2)On the basis of medium and long-term runoff forecasting research,carry out inter-basin water transfer and supply joint forecasting and dispatching research.Firstly,only mid-term monthly runoff forecast information is considered,and multiple sets of scheduling plans considering mid-term runoff forecast are set up.These plans use monthly runoff forecasts to optimize water diversion and water supply scheduling rules in different months of the flood season and non-flood season.By comparing the scheduling results of different schemes,analyze the effectiveness of the monthly runoff forecast information in different periods of the year,and determine the optimal scheduling method that considers the mid-term runoff forecast,that is,considering the effectiveness of the water diversion of the scheduling method of the monthly runoff forecast from April to October highest.Based on the optimal mid-term forecast scheduling method,the long-term flood season total runoff forecast information is further considered,and the flood season total runoff forecast is used to determine the lower limit of the diversion water during the period.Set up multiple sets of scheduling schemes that are coupled to consider medium and long-term runoff forecasts.These schemes use monthly runoff forecasts and total flood season runoff forecasts obtained at different times to optimize water diversion and water supply scheduling rules in different months.By comparing the scheduling results of each plan,the most reasonable way of coupling utilization of medium-term and long-term runoff forecasting is analyzed.(3)On the basis of the most reasonable coupling mode of mid-and long-term runoff forecasting,the influence of forecast uncertainty on inter-basin water diversion operation is analyzed.First,input the completely accurate runoff forecast into the dispatch map for optimization simulation,and compare the dispatch result with the dispatch result considering the existing forecast.Then,randomly generate mid-and long-term runoff forecasts with different forecast variances,and after completing the optimization simulation,compare and analyze the impact of forecast uncertainty on water diversion efficiency.