Study On Power Generation And Ecological Risk Operation Of Reservoir In The Lower Lancang River

There are a lot of uncertain factors in the process of water resources development and utilization.Due to the existence of the uncertain factors,water resources regulation and control face multiple risks,which aggravates the competition between the power generation and ecological departments of the multi-objective utilization of water resources in the basin.How to effectively coordinate the relationship between power generation?ecology and their corresponding risks makes the coordinated and effective development of the system become crucial.In this paper,the Nuozhadu,Jinghong and Ganlanba cascade power stations in the lower reaches of the Lancang River are studied as research objects to explore the risks faced by the cascade power stations in the lower reaches of Lancang River.Through power generation risk dispatching,power generation benefits and risk-balanced dispatching decisions under risk conditions are provided to decision makers.Through ecological risk dispatching,the relationship between power generation and ecological risk is quantitatively analyzed to reduce the ecological risk in the lower reaches of the Lancang River.The research results have important practical significance for improving the water resources management method of the Lancang River Basin,improving the scientific dispatch level of the reservoir,and ensuring the health of the river ecosystem.The main research content and results of the thesis include the following parts:(1)Based on the long series of runoff data in the lower reaches of the Lancang River,the statistical characteristics,annual distribution,and trend characteristics of runoff are analyzed.Monte Carlo simulation is used to obtain simulated runoff values with the statistical characteristics of long series of runoff data.(2)In order to describe the uncertainty of runoff inflow,the runoff data obtained by Monte Carlo simulation is used as input data to construct a scenario tree model that expresses the uncertainty of inflow.In order to improve the calculation efficiency of the reservoir operation model,scenario reduction method is used to reduce the scenario tree to different degrees to obtain the scenario tree after different reduction degrees and the corresponding probability of each scenario.(3)Adopt the mean-variance theory in economics to represent the benefits and risks during the operation of cascade power plants,establish a risk-benefit balanced cascade power plant scheduling model that considers the risk factor,and analyze the feasibility of the risk-benefit model and the impact of different reductions on the model results,it provides support for decision makers to formulate risk-benefit balanced scheduling plans under risk conditions.(4)In order to better determine the range of ecological flow in the natural state,using the hydrological data before hydrological variation as a basis,the ecological flow and ecological risk flow thresholds are determined.The model of maximum expected power generation and minimum expected ecological risk under uncertain conditions is established,and the correlation between power generation and ecological risk is quantitatively studied,and the sensitivity analysis of the degree of scenario tree reduction to the results is analyzed.