Warning assessment of urban ecological security based on fuzzy matter-element theory

The deterioration of ecological environment has aroused broad attention. This paper constructed an urban ecological security warning assessment index system. The index system was composed of vigor, organizational structure, resilience, maintenance of ecosystem service and human health. Then it established an assessment model of urban ecological security warning based on fuzzy matter-element theory. In the model, the paper used entropy method to endow indexes weights and it could decrease the influence of subjective factors. Then the paper used the model to assess the ecological security condition of Chongqing city from 1997 to 2007. The results show that ecological security conditions of Chongqing improve during the study time. Urban ecological security conditions from 1997 to 2000 and from 2001 to 2007 are in middle warning degree and ordinary warning degree respectively. However, urban ecological security of Chongqing need to be improved in the days ahead.