Comprehensive Evaluation Of Sustainable Development Of Urban Ecosystem In Lanzhou City

Lanzhou is a city with a very long history. Its rich cultural heritage, the uniquegeographical location and political status that becomes more and more important, whichmakes the research for ecosystem representative and unique. The results have a certainreference value for the further improvement of social and economic development andurban construction in China’s current stage. In recent years, with the rapid developmentof economy and urban construction, there appeared some new problems in Lanzhoucity.In recent years the research for Lanzhou urban ecosystem mainly focuses onecosystem health evaluation and, despite the emphasis on the objectiveness andpracticability, there is no further extension of the basic theory. In this paper, insustainable development perspective, the whole running status of urban ecosystem isconsidered as a single topic based on the previous studies, using the systemic sciencemethod to make a research for status of operation and development of urban eco system,focusing on analyzing status of sustainable development urban ecosystem. On the basisof the connotation of sustainable development, an evaluation index system ofsustainable development of Lanzhou urban ecosystem is established. The evaluationindex system included28indicators. Lanzhou urban ecosystem was comprehensivelyevaluated using set pair analysis (SPA) from the viewpoint of the level, coordinationdegree and persistence degree of development. The“obstacle degree” was cited andobstacle factors were calculated that influenced sustainable development of Lanzhouurban ecosystem. The results showed that:(1)In2004-2011，sustainable development of Lanzhou urban ecosystem was in themedium level, with a higher level of coordination degree and a lower level ofpersistence degree.(2)There was obvious divergence of development where the level declined rapidlyin natural resources and environmental subsystem, increased in economic subsystem,and rose greatly in fluctuation in social subsystem. In this sense, the structure ofLanzhou urban ecosystem is unstable so far.(3) obstacle factors which influenced sustainable development of Lanzhou urbanecosystem were as follows: GDP per capita; Average annual GDP growth rate; Gross export per GDP; Number of college students per10000persons; Emergence of floatingdust and sand dust weather; Number of hospital beds per1000persons; Industrialwastewater discharged quantity.After analyzing and diagnosing these obstacle factors, the paper finally put forwardto some suggestions on sustainable development against obstacle factors.