The Allocation Of Water Resources In The Midstream Of Heihe River For The ”97 Water Diversion Scheme”and The ”Three Red Lines”

Rapid economic and societal development caused increasing in water resource consumption,understanding how to balance the discrepancy between economic and social water use and ecological water is an urgent problem to be solved,especially in arid areas.Heihe River is the second-largest inland river in China,this problem is notable.This paper takes the midstream of Heihe River as the research object,the“Water Distribution Plan for the Mainstream of the Heihe River”(97 Water Diversion Scheme)controls the discharge of Yingluo Gorge and Zhengyi Gorge,the“Opinions of applying the strictest water resources control system”(Three Red Lines)restrict the water use.With the development of the economy and agriculture in the midstream,Zhengyi Gorge's discharge cannot reach the Heihe River's ecological water downstream.In this paper,the water consumption and water use efficiency are analyzed,obtain the change rules and main influencing factors.On this basis,analyze the water consumption's influence factors.through the water balance,obtain a verification result.The verification result is input into MIKE BASIN,through the reasonable allocation of water resources,the water resources allocation results that meet the"97"water diversion scheme and"three red lines"are obtained.The main results are as follows:(1)The overall change trend of total water consumption from 2000 to 2018 is decreasing,and the change of water consumption in the midstream of the Heihe River is mainly affected by precipitation,incoming water conditions,and irrigation area.The score of water use efficiency evaluation is 71.37,and water use level itself and water use efficiency have a great influence on water use efficiency.(2)The water consumption in the midstream of the Heihe River fluctuated from 2000 to 2017,but the overall change was stable.Through the principal component analysis and correlation analysis,the water quantity is the most important factor to evapotranspiration.The main influencing factors except the water quantity are landuse type,followed by rainfall and temperature by using the geographical detector.The results of correlation analysis and RDA analysis show that the water condition has obvious results for the variation of water consumption coefficient.(3)Though the Mike basin model to simulate and calibrate the water resources allocation results from 2000 to 2018,the correlation coefficient of each irrigation area is greater than 0.5,which indicates that the simulation effect is good and can be used for water resources allocation in the midstream of Heihe River.(4)Under the condition of current water demand,the water intake indexes in 90%,75%,50%,25%,and 10%inflow years are calculated,obtain the water control indexes of the midstream of Heihe River.(5)This paper puts forward the water resources regulation strategy to meet the"97"water diversion scheme and the total water consumption in Zhangye.The first is to reduce the cultivated land area in the midstream to 1200km~2;the second is to improve the water use efficiency and appropriately return the cultivated land to 1533km~2.The water resources allocation schemes under different inflow conditions are simulated under these two conditions,and the diversion and water consumption of each irrigation area are obtained.