Study On Urban Ecological Security Assessment

With the rapid development and advance of urbanization, the relationshipbetween ecological security and the economic and social development of humanbecomes increasingly close. As the gathering area of population and economy, urbanecological security is the basis and core of both national and regional ecologicalsecurity. It is of great significance for the sustainable development of a city’seconomy and society to explore and research the construction of the evaluationsystem of urban ecological security so as to give scientific and reasonable assessment.The article discussed the connotation of ecological security, defined the conceptof urban ecological security and summarized the latest research progress in ecologicalsecurity and its assessment. Literature research method was used to draw lessons fromexisting literature of its relatively mature evaluation index system of urban ecologicalsecurity. Besides, the dominant factors influencing the urban ecological security werefound out through analyzing the problems that urban ecological security faced. Thus,the paper builded up the evaluation index system of urban ecological security,including4levels and8indicators, on the basis of the conceptual model ofPressure-State-Response. And it divided urban ecological security level into differentgrades. The empirical part adopted Analytic Hierarchy Process (AHP) and PrincipalComponent Analysis (PCA) respectively to longitudinally evaluate and study theecological security of Ningbo city from2002to2011. Such approaches were alsoused to carry out horizontal comparison and research among the following cities,Ningbo city, Huzhou city, Hangzhou city and Shaoxing city of their evaluation resultsin2011.The comprehensive index of Ningbo city’s ecological security under AHP was0.5739,0.5789,0.5998,0.6258,0.6282,0.6262,0.6656,0.6654,0.6725and0.7162respectively from2002to2011. According to the grade division of urban ecologicalsecurity assessment, the ecological security of Ningbo city kept at the level ofrelatively safety in the last decade.The comprehensive score of Ningbo city’s ecological security under PCA was-1.3213,-0.7930,-0.4963,-0.0377,0.0795,0.0559,0.3868,0.3130,0.7645and1.0486respectively. The sequence of ecological securitylevel of Ningbo city under the two evaluation methods mentioned above from high tolow was2011,2010,2008,2009,2006,2007,2005,2004,2003,2002, which showeda trend of increase year by year on the whole. When compared with the ecologicalsecurity of Huzhou city, Hangzhou city and Shaoxing city in2011horizontally, thecomprehensive index of these four cities under AHP was0.7223,0.6831,0.7780and0.7136respectively. Combined with the grade division of urban ecological securityassessment, the ecological security of Hangzhou city was in the state of ideal safety,while the other ones were in the state of relatively safety. Meanwhile, thecomprehensive score of the four cities’ ecological security under PCA was-0.1769,-0.4013,0.9138and-0.3356respectively. The sequence of ecological security level ofthe four cities under the two evaluation methods from high to low was Hangzhou city,Ningbo city, Shaoxing city and Huzhou city. Finally the paper analyzed the problemsof ecological security that Ningbo city faced and put forward relevantcountermeasures and suggestions.