Study On Ecological Flow Analysis And Optimal Allocation Of Water Resources In Shiyang River Basin

The Shiyang River Basin is located in the inland arid region of northwest my country.Due to the lack of water resources in the river basin,the problem of ecological environment has been outstanding for many years,which has seriously restricted and affected the economic development of the river basin.Since 2007,the government has paid attention to the ecological problems of the Shiyang River Basin.Through more than 10 years of restoration and governance,the ecological environment of the river basin has improved.This paper aims to arouse public water resources protection and water conservation awareness,protect water sources,and achieve balanced development of the Shiyang River's ecological water system through the analysis of the ecological flow of the Shiyang River Basin and the research on the optimal allocation of water resources,so as to achieve water resources.Sustainable use.This article starts from the three aspects of water resources evaluation,ecological flow analysis and water resources optimization allocation,and analyzes and explains that through field investigation and formula calculation,the use of diving evaporation method,research method based on remote sensing and geographic information system,quota method,three Several common hydrological methods and hydraulics methods are used to calculate the ecological water demand of natural vegetation,artificial ecological water demand and river ecological flow.The results are summarized as follows:(1)Through the analysis of water resources trends,it is found that the runoff of the Shiyang River Basin has increased steadily,groundwater resources have continued to increase,groundwater extraction has decreased,cross-basin recharge water volume has stabilized,and the development of water resources is in good shape.In 2018,the annual precipitation of the Shiyang River Basin increased by 14.3%compared with the average for many years;the surface water resources increased by 5.4%,the groundwater resources increased by 38.2%,and the artificial groundwater extraction decreased by 28.73%.(2)Obtain the ecological water demand of natural vegetation,artificial ecological lake water demand and river ecological flow in the Shiyang River Basin.The water demand of natural vegetation in the watershed is 1.08×10~9?3.19×10~9m~3,the water demand of artificial ecological lake is 1.2223×10~8m~3,the comparison and optimization of various methods of river ecological flow select the calculation value of 10%natural runoff method 2.661×10~8m~3.(3)The spatial and temporal distribution of water resources in the Shiyang River Basin is significantly different.Precipitation in the basin gradually increased from northeast to southwest,with uneven distribution during the year,rainy summer and autumn,less rain in winter and spring,and alternating periods of dry season during wet season;river runoff showed seasonal hydrological changes of"spring flood,summer flood,autumn level,winter dry"Regularly,the space gradually increases from southwest to northeast.(4)Based on the ecological flow,an optimized allocation plan for water resources in the Shiyang River Basin is proposed.It is proposed to increase the protection of ecological vegetation,scientifically formulate water dispatching schemes for reservoirs,promote water-saving agriculture,and establish and improve a system of inter-basin water transfer.Ecological flow is the main focus of a region or river basin in terms of ecological governance and ecological environment construction.Especially in dry and semi-arid areas,ecological flow has become a major issue affecting water resources.Therefore,this paper is a timely and practical work on the analysis of the ecological flow and the optimal allocation of water resources in the Shiyang River Basin.