Study On The Determination And Control Mechanism Of River Ecological Flow Considering The Amount Of Lift

The increase of long-term unreasonable water extraction by human activities inside and outside the river,resulting in the problem of insufficient ecological flow or even ecological base flow guarantee of the river is the focus of current research attention.In order to gradually improve the water ecological environment,alleviate the problem of insufficient water quantity and unhealthy water quality in rivers,cooperate with the need of strong supervision,and implement the requirements of the Ministry of Water Resources on ecological flow determination and guarantee,we carried out a study on ecological flow determination and process-oriented control mechanism of rivers,from ecological flow definition,construction of regulation bank,mechanism design to system implementation,based on the ecological flow interval oriented by adaptability and operability The research is based on the determination of ecological flow intervals with adaptability and operability,considering both water supply and water demand sides,and combining qualitative and quantitative results,so that the calculation results can be adapted to spatial and temporal changes and changes in supply and demand.The main research contents and results of the thesis are as follows:(1)Through the analysis of concepts and connotations related to ecological base flow,ecological water demand and ecological flow,a new idea and practice of determining ecological flow of rivers through ecological base flow plus feasible enhancement is proposed with the goal of solving the problems of difficult to calculate ecological flow of rivers quantitatively and poor adaptability of assessment and management.Based on this approach,the model method of water demand calculation,the service object categories,the relationship between water extraction and use in river sections and the feasible enhancement method are sorted out and integrated,and the reasonableness and operability of this approach are illustrated through feasibility and adaptability analysis.(2)In view of the influence of different spatial and temporal distribution,ecological water demand and water supply dynamics on the enhancement amount in ecological flow,a more scientific approach of determining ecological flow through regulation and process control through mechanism is proposed.Considering the problem of insufficient adaptability of one value or a set of values of ecological flow,an intervalized regulation model is constructed and combined with the adaptive regulation model for determining the optimal interval for decision making,and for carrying out subsequent calculations,qualitative and quantitative regulations are integrated in the form of a regulation library to realize the adaptive calculation of ecological flow of rivers.On this basis,the river ecological flow monitoring and early warning,assessment and evaluation,linkage and control,dynamic feedback and rolling correction mechanism are designed to provide support for strong regulation in the process under the river manager system.(3)Taking the "Lin-Wei" section of the Wei River main stream as an example,we analyzed and calculated the ecological flow at the Linjiacun section and the Weijiabao section.Through the analysis of resource characteristics and ecological demand of this river section,the service objects were determined as ecological base flow,fish water demand,landscape water demand and irrigation water demand of Baojixia irrigation area,the priority of water consumption in each month of the year was determined according to the overload rate,the ecological base flow was calculated by the improved intra-annual spreading method,and the elevated volume was determined by the interval regulation,and the results of ecological flow calculation in different typical years were obtained.The results show that for the Linjiacun cross-section,it can be upgraded to 20.2 m3/s in April and June in a flat water year and to 8.86 m3/s in April in a dry water year;for the Weijiabao cross-section,it can be upgraded to 16.0 m3/s in April-June in a flat water year and to 2.15 m3/s in April in a particularly dry water year.(4)A river ecological flow determination and process-oriented control system was established based on the integrated platform.With the support of this system,relevant business processes and business relationships are realized by means of comprehensive integration,and assessment and control are carried out for key links to adapt to dynamic changes,and an example application is carried out for the Linjiacun-Weijiabao river section of the Weihe River main stream.