Comprehensive Assessment Of Urban Ecosystem Carrying Capacity

Urban ecosystem is a Social-Economic-Natural Complex made of human beings and their surrounding environment, and is characterized by integrity and synthesis. Hence, in order to meet the challenges of urban sustainable development and eco-city building, the Urban Ecosystem Carrying Capacity (UECC) are introduced and studied as an index of the interactions between environment, resource and social-economic development. Through this index, how the three kinds of capacities function to sustain urban ecosystem is figured out in both theory fundamentals and quantitative models. The research specifically includes the followings:1. The concept of UECC is introduced with comprehensive understanding of urban system's structure and functions. Furthermore, its characteristics and connotation are also interpreted from aspects of objectivity, integrity, organism, hierarchy, threshold and relative balance etc. Compared with traditional concept, the UECC includes development ability, which makes it more dynamic.2. A comprehensive assessment model of UECC is introduced, which makes up of three parts, namely the urban ecosystem support model (included natural carrying model and the acquired carrying model), the urban ecosystem pressure model and the urban ecosystem carrying capacity model.3. A case study is conducted in Hangzhou City. With the assessment on dynamic changes of land use, landscape and environmental quality, the structure and function of urban ecosystem is analyzed, it is showed that there are various factors to restrict the urban ecosystem development, mostly including environmental quality, resource allocation, social-economic development and urban and rural structure.4. By the application of the assessment model of UECC, the integrated carrying capacity of Hangzhou City is evaluated and the result shows that, the UECC and pressure in Hangzhou is relatively balanced, and the urban ecosystem is basically healthy on the whole, but in some parts, adjustment should be taken in terms of economic activities and ecological restorations.5. Finally, series of policies and measures in resource, environment, economy and society should be established in order to improve the urban ecosystem carrying capacity.