Research On Diversion Scheduling Of Dahuofang Reservoir Based On Hydrological Analysis

As an important earth resource,water is related to the national economy and people's livelihood.Although water resources can be continuously supplemented and updated through the global hydrological cycle,the economic and social development in recent years has led to a sharp increase in water demand,coupled with insufficient attention to water resources,resulting in a long-term renewal of water resources,far from meeting the speed of human consumption.The development of cities and industries is inseparable from the water source.The production and life of residents are also inseparable from the water source.To solve the contradiction between supply and demand of water resources,cross-basin water transfer projects are a good solution.The essence of solving the water resources problem by inter-basin water transfer project is to redistribute water resources in space,solve the problem of uneven distribution of water resources on geographical factors,and avoid the situation that the utilization of water resources is too high or too low;The reservoir can redistribute water resources in the time dimension.In essence,it adjusts the storage capacity according to the time change,accumulates the abundance and eliminates the dry water,and eliminates the extreme phenomenon of a large number of abandoned water in the wet season and severe water shortage in the dry season.The combined use of inter-basin water transfer projects and reservoirs is of positive significance for improving the utilization of water resources and ensuring urban industrial and domestic water use.In this paper,the inter-basin transfer area and the Dahuofang Reservoir are taken as research objects.The natural water data from the two basins(1980-2011)are selected,and the inter-annual and inter-annual runoffs are carried out for the inter-basin transfer area and the Dahuofang reservoir watershed analysis.By establishing the Copula function model,the law of the runoff of both is analyzed.On the basis of this,under the premise of satisfying the water supply guarantee rate of the Dahuofang Reservoir,the optimal dispatching model of the Dahuofang Reservoir with the smallest water diversion and the largest accumulated water storage capacity during the reservoir period is established to analyze the water diversion process of the Dahuofang Reservoir to achieve optimal water diversion.Improve the utilization of water resources.The main research contents and results are as follows:(1)The mathematical statistics method was used to analyze the runoff characteristics of the trans-basin transfer area and the Dahuofang reservoir.The results show that the average annual runoff of the trans-basin transfer area and the runoff of each incoming water period(the flood season,spring,dry season)are all above the Dahuofang Reservoir watershed,and the distribution of the larger Hufang Reservoir is evenly distributed during the year,and the runoff varies from year to year.The larger hull reservoir is stable,so it is feasible to provide runoff compensation for the Dahuofang reservoir basin as a water source area.(2)The Copula function theory is used to establish the mathematical model of the runoff encounter between the trans-basin transfer area and the Dahuofang reservoir,and the Copula function form with high fitting degree is preferred.Using the Copula function to analyze the runoff encounter probability,we can see that the cross-basin transfer area and the Dahuofang Reservoir have a simultaneous runoff probability of more than 70% in the whole year,flood season,spring and dry season,which brings the water diversion of the Dahuofang Reservoir across the basin.unfavorable.However,considering the stability and abundant runoff of the trans-basin transfer area and the limitations of its low water probability,the inter-basin transfer area can still provide water diversion conditions and water supply guarantee for runoff compensation of Dahuofang Reservoir.(3)Combined with the law of runoff and abundance in the trans-basin transfer area and the Dahuofang reservoir,a multi-objective model with the smallest water diversion in the Dahuofang Reservoir and the largest accumulated water storage in the reservoir period was established.The paper uses this model to design the water diversion scheme for the long-term series of runoff data before and after the implementation of the Dahuofang Reservoir water delivery project(1980-2011)and after the implementation(2012-2017),and compares the water diversion under the current diversion rules of the Dahuofang Reservoir.As a result,the validity of the model is verified.Through the long series of diversion regulation calculations,before the implementation of the water delivery project,the water diversion process after the optimization of the multi-objective model,the water diversion and the amount of water abandonment are smaller,the water storage capacity during the reservoir period is larger,and the water shortage in the downstream water area of the Dahuofang Reservoir occurs.The risk is small.After the implementation of the water delivery project,by comparing the actual water diversion process of the Dahuofang Reservoir in 2012-2017,the multi-objective model calculates the total water diversion by 20.2%,the total abandoned water by 21.2%,and the monthly average storage capacity by 3.1%.