Study On Ecological Evaluation Of Port And Driving Mechanism Of Ecological Elements Based On SD-EEF Model

In recent years,with the rapid development of China economy which promote domestic and foreign trade,port and shipping industry are developing rapidly.However,port and environment contradiction is highlighted because the demand on resources of the port and the emissions of environmental pollution are increasing,which leads to serious challenge to sustainable development of the port and the city.Evaluating port ecological environment and port sustainability can make contribution on forecasting the evolution of complex port ecosystem,contribute to scientific and rational development strategy,and promote coordinated development between port and environment.Furthermore,it is an important way to put the theories of ecological port into practice.This paper introduces a modified model of port ecological footprint,called port EEF model,which combines emergy analysis with conventional model of port ecological footprint and has more calculation accounts.To analyze the port ecological budget and quantify the sustainability of the port,this paper calculates the port ecological footprint and the ecological carrying capacity.Moreover,this paper makes an analysis on the effect of these factors and their interactions on port ecological footprint through a multiple linear regression equation based on principal component analysis and regression analysis.On the basis of the port EEF model and the analysis of socio-economic driving force of port ecological footprint,this paper determines each causality of main variables in port ecosystem and build the port SD-EEF model by introducing system dynamics which combines scenario simulation method with ecological footprint model,so as to simulate the development of port ecosystem.At last,this paper propose a numeral case which has three simulation schemes,including plan 1 which is the existing development mode,plan 2 which adjust energy structure of the port,plan 3 which is based on emissions reduction and energy efficiency enhancement.The results illustrate that the port is currently on an unsustainable trajectory and the economic development of the hinterland has a strong positive effect on the port ecological footprint.The ecological deficit would continue to expand according to plan 1,plan 2 can’t effectively reduce the ecological carrying capacity index,while plan 3 can effectively reduce the ecological carrying capacity index,thus significantly improving ecological condition.The port SD-EEF model can objectively evaluate the ecological status of the port and effectively forecast the development trend of port ecological status,which can provide theoretical guidance for the construction of ecological port.