Study On Water Ecological Impact Of Reservoir Operation Period Based On BN

With the rapid development of society,economy and the contradiction between population growth and water resources and water environment in China,the aquatic ecosystem has been threatened.Reservoirs provide fresh water resources,aquatic products,power energy and other materials for human production and life,and can also regulate regional climate,purify the surrounding air,improve the local environment,improve the quality of life of residents and other services.The research on the influence of reservoir on water ecosystem during the operation is of great significance to realize the coordinated development between human development and nature as well as sustainable development.Based on the theory of water ecosystem service ecological mechanism,a conceptual model for analyzing the impact of reservoir operation on water ecosystem was established.From the perspective of the "pressure" generated by human activities in the regional control unit of the reservoir area and the "response" made by the water ecosystem in the reservoir area,the correlation between the reservoir operation and the water ecosystem process is established through the driving force,response factor,water ecosystem structure,water ecosystem process and water ecosystem service.The Bayesian network model was selected,and the method combining graph theory and probability theory was used to represent the causal relationship between nodes with directed arrows,and the conditional probability table was constructed according to the literature search method and data learning method to represent the relationship between the degree of dependence between nodes.Combining with the characteristics of this study,Netica is selected as the quantification tool of the application software.In this study,Biliu River Reservoir in Dalian City was selected as the research example,and Dalian City,where Biliu River Reservoir is located,was taken as the control unit to complete the localization of the model.This paper analyzes the water ecological service level of Biliu River reservoir during the period of operation from 2010 to 2019,predicts various driving forces and response factors in 2035 according to the economic and social development situation and policy analysis,and makes a predictive evaluation of the water ecological service level of Biliu River reservoir in 2035.Results show that as the largest water garden in Dalian river reservoir water quality purification services and aquatic habitat supply service level enhances unceasingly,but the uncertainty of non-point source pollution still caused a lot of potential threat for reservoir water ecology,green river reservoir water supply and hydroelectric power supply service constantly degradation trends,The reason lies in the imbalance between supply and demand caused by the development of social economy and the improvement of aquatic level.To sum up,it puts forward some suggestions and measures,such as water resources protection,strengthening pollution source control,strengthening supervision capacity,implementing funds,and establishing joint inspection system of multiple departments.