Dynamic Evaluation Of Water Ecological Carrying Capacity In Reservoir Area Based On SD Model

With the rapid development of the society,the contradiction between inhabitant demand,economy development and water resources,water environment is becoming increasingly prominent at the present stage.The research on the water ecological carrying capacity have become a link between the two.In recent years,researches in Chinese academia were mainly implemented on the ecological carrying capacity of river basin water and urban water.However,there are few researches on the ecological carrying capacity of water in the reservoir area.The reservoir area provides residents with various kinds of water for living and production.Therefore,studies on the the dynamic development and the changing trend prediction for the water ecological carrying capacity of the reservoir area is critical.The research results can provide a decision-making reference for the sustainable development of the reservoir area and promote the relationship between social economy and water resources coordinated development.The Dahuofang Reservoir is selected as the case study in this paper.Combined with the research theory of water ecological carrying capacity of the reservoir,DPSIR method,ecological footprint method,system dynamics method,and fuzzy comprehensive evaluation method are adopted to establish a water ecological carrying capacity model of the reservoir for dynamic evaluation.Firstly,the the DPSIR method was used to establish the water eco-city carrying capacity index system.Meanwhile,the ecological footprint method was used to evaluate the current use efficiency of various types of water in the reservoir area in order to judge the water resources carrying capacity of the reservoir area.Subsequently,a System Dynamics(SD)model of the water ecological carrying capacity of the reservoir area.In this model,the city Fushun,where the Dahuofang reservoir area is located,is selected as the control unit.After finishing the works including setting system indicators,establishing the formula,drawing the system flow chart and verifing the model,various indicators of water ecological carrying capacity in the reservoir area from 2020 to 2035 can be simulated and predicted.In addition,the decision indicators,incluidng population,GDP,COD emissions,entire water demand,and pressre of supply and demand,are employed to adjust the variables that affect the decision indicators.Different development patterns of current status continuous type,economic growth type,Green and environmental protection type,comprehensivedevelopment type are set.Based on the prediction value for various indicators in 2035,the fuzzy comprehensive evaluation method is used to optimize the plan.The water ecological carrying capacity of each plan in 2035 is evaluated to provide suggestions for the reservoir area developent.The result shows the water resources in Dahuofang reservoir area are in an ecological deficit state and the water supply has been in an unbearable state.Fushun City should promptly adjust the water supply problems in Dahuofang reservoir area.After establishing the system dynamics model,the model is proved to be feasible through the verification.The changings of each system index from 2020 to 2035 are also predicted.The prediction result reveals that the comprehensive evaluation values of the water ecological carrying capacity of the four schemes are: comprehensive development type(5.39)> green environmental protection type(4.23)> economic growth type(3.90)> current development type(3.29).Therefore,the comprehensive development type is the optimal selection for the development of water ecological carrying capacity in Huofang Reservoir Area.According to the plan,effective measures such as saving water resources,reducing pollutant emissions,establishing a smart storage area,improving industrial structure,and introducing talents are proposed for the Dahufang reservoir area.