Study On Ecological Operation Of Cascade Reservoirs In Yangtze River Based On Ecological Flow

With the development of social economy and the improvement of people’s living standards,the demand for resources is increasing.Therefore,human beings start from water resources and obtain resources through dam storage and power generation.Because cascade reservoir development is not a water conservancy project in effect,it will bring huge and considerable superimposed economic benefits,at the same time,it will certainly bring much or little superimposed negative impact on the ecological environment of the basin.In the end,the impact will become more and more serious.So through the study and understanding of the progress at home and abroad,the basic theory and method of ecological dispatching of cascade reservoirs in the Yangtze River are deeply studied.After analyzing the change of hydrological situation in the middle and upper reaches of the Yangtze River,the relationship between discharge and ecological flow in the lower reaches of the reservoir is compared by establishing reservoir dispatching model.According to the existing reservoir dispatching rules,the ecological dispatching measures of cascade reservoirs in the Yangtze River are In order to achieve better prospects.The main contents of this paper include:(1)The concept and principle of ecological dispatching,ecological objectives of cascade reservoirs in the middle and upper reaches of the Yangtze River,optimal dispatching models under various constraints,optimization algorithms and reservoir dispatching management system are studied.(2)The daily runoff data of Pingshan and Yichang hydrological stations in the main stream of the Yangtze River are selected to analyze the characteristics of runoff variation under natural and reservoir regulation,including trend analysis and catastrophe point analysis,and the differences between natural runoff process and Post-regulation runoff process are compared.The index system of eco-hydrological change reflecting the characteristics of river discharge change is established.The variation range method(RVA method)is used to compare the difference of flow regime between natural and cascade reservoirs.The relationship between runoff and ecological water demand was established by annual distribution method,and the process of ecological water flow was obtained.(3)A cascade reservoir dispatching model in the middle and upper reaches of the Yangtze River is established.The genetic algorithm is used to solve the model.Three typical horizontal years are selected for simulation calculation and analysis.The simulation results can provide a reference for decision makers of cascade reservoir dispatching in the middle and upper reaches of the Yangtze River to carry out ecological dispatching research.