Urban Ecosystem Health Assessment Model And Its Application

With the accelerating process of urbanization, population has crowded to citiessince20centuries. Nevertheless, due to many natural factors as global climate change,eco-environmental stress etc, and numerous humanities factors as the governmentdecision-making management within the region, the environmental awareness of thepublic, the impact from the city and the surrounding environment, the city has alsobecome increasingly vulnerable. Therefore, the urban ecosystem health evaluation,regulation and management have caused great concern of both academia andgovernment policy makers and managers.This article has analyzed and summed up urban ecosystem’s concept, structure,function and theory of urban ecosystem health assessment. Urban ecosystem health isattributed to the harmonious development in five aspects such as vigor, structure,resilience, functional maintenance and population health. Though availableresearchers have established many assessment models for the urban ecosystem health,few of them can premeditate the dynamical interactions between the variousindicators. In this paper, we propose a novel non-equilibrium statistical mechanicsmodel based on maximum flux principle (MFP) and information entropy, showinggreat superiority over the existing models. Employing the self-organization featuremap (SOM) neural network simulation techniques, the new model can better representthe characteristics of urban ecosystem health. In case studies, we obtained the healthstatus from2001~2009in Tianjin using this new model, and urban ecosystem healthstatus in each year has been elaborated, which shows significant increases with years.Health evaluation in six cities of Beijing, Dalian, Shanghai, Wuhan, Xiamen, andGuangzhou shows that six cities in1995~2003are in relative health status. We thenanalyze the factors that affect the health status of the various cities. Finally, from therichness of the basin water resources perspective, we get results that basin4waterresources is extremely dry, and basin1,2,3are relatively dry, while basin5,6,7,8,9are living in the middle. The evaluation results have been accordingly compared withthe projection pursuit dynamic cluster model, fuzzy clustering neural networks, fuzzycomprehensive evaluation method and the ART network evaluation method todetermine the validity of the model of non-equilibrium statistical mechanics. Owing to its ability of revealing the evolution of the dynamic mechanism and thetemporal-spatial evolution of the urban ecosystem, our model shows great advantagein the urban ecosystem assessment, and is potential in prediction, regulation andmanagement of the health status.