Fuzzy comprehensive evaluation of urban ecological safety in Shenzhen city

Urban ecological safety evaluation is the basis of the forecasting and early warning of ecological safety conditions. It is also an effective way to manage urban ecosystem. Based on pressure-state-response model, this paper established an evaluation index system of urban ecological safety. Then it introduced fuzzy mathematics into urban ecological safety evaluation and established a fuzzy comprehensive evaluation model. In the model, the paper used analytic hierarchy process (AHP) and entropy methods to endow indexes weights. This weighting method utilized the advantages of objective and subjective methods. Finally the paper evaluated urban ecological safety conditions in Shenzhen city from 1997 to 2008. The results show that ecological safety conditions in Shenzhen are satisfactory and there is a tendency of gradual improvement. Fuzzy comprehensive evaluation method can assess urban ecological safety conditions objectively and comprehensively. In addition, it provides a new way for urban ecological safety evaluation.