A Study On Water Resource Allocation In The Ulungu River Basin Considering Runoff Forecasting

Watershed runoff forecasting is the basis for reservoir control,and accurate runoff forecasting can provide effective guidance for decision-makers to effectively prevent drought and water scarcity risks.At present,the reservoir group scheduling in most river basins lacks more accurate runoff forecast information,and often abandons water when the incoming water is abundant,and has to give up the irrigation task of some agricultural land when the incoming water is dry,which does not make full use of local water resources and affects the comprehensive utilization efficiency of water resources in the river basin.Due to the advancement of globalization and rapid population growth,the expansion of arable land has led to a sharp increase in irrigation demand,water resources in inland arid irrigation areas are becoming more and more scarce,and the competition between industrial domestic water,ecological water and agricultural irrigation water is becoming increasingly fierce.In order to realize the scientific management and rational distribution of water in irrigation areas,it is of great significance to study the scientific water allocation in the inland river basins in arid areas.Therefore,the research on water resources allocation based on runoff forecasting is of great practical significance for improving the utilization efficiency of water resources in river basins.Taking the inland river-Ulungu River Basin in Altay Prefecture of Xinjiang as the research object,this paper constructs a SWAT distributed hydrological model in the Ulungu River Basin for drainage simulation,establishes the optim al allocation model of water resources in the Ulungu River Basin and the multi-objective joint scheduling model of reservoir group,and formulates the agricultural irrigation rotation irrigation scheme,which plays an important role in maximizing the comprehensive benefits of limited water resources in the basin and ensuring the efficient and balanced utilization of water resources in the upper,middle and lower reaches of the river.The main research results obtained in this paper are as follows:(1)ArcSWAT2012.10.5.24 was used on the ArcGIS platform to establish a distributed SWAT hydrological model of the Ulungu River Basin,using existing basic data to simulate runoff,and using the measured monthly runoff data of two hydrological stations to calibrate and verify the model,and the average relative error,correlation coefficient and Nash coefficient of 2015-2016 were-18.9%,0.84 and 0.80,respectively;The correlation coefficient and Nash coefficient were-15.05%,0.88 and 0.89,respectively,and the three evaluation indexes of the rate period and the verification period met the accuracy requirements,indicating that the SWAT model had good applicability to runoff simulation in the Ulungu River Basin.(2)The runoff process of the river basin in 2023 is predicted,and the analysis of the balance of water supply and demand shows that there will be a shortage of water resources in the Ulungu River Basin in 2023.In this context,the optimal allocation model of water resources in the Ulungu River Basin was established,the GA algorithm was used to solve the model,the three-level distribution scheme of district,county-irrigation area-Longkou was formulated,the rotational irrigation scheme in the basin was formulated considering the throttling strategy of the Ulungu River Basin,which effectively reduced the problem of agricultural water shortage,and a fair,reliable and reasonable agricultural irrigation water supply scheme in the Ulungu River Basin was formulated,which alleviated the contradiction and conflict of agricultural irrigation water intake between districts,counties and irrigation areas,and laid a solid foundation for subsequent research.(3)In order to realize the water resources allocation scheme of the Ulungu River Basin,a multiobjective operation model of the reservoir group in the basin was established,and the minimum irrigation water shortage and the minimum ecological water shortage of forest and grass in the river valley were used as the objective function of this multi-objective joint dispatch,and the NSGA-II algorithm was used to solve the model,and the reservoir scheduling results considering the forecast were obtained,and the research results provided an important reference for the annual scheduling of the reservoir group in the Ulungu River Basin.