Ecological Security Assessment of Tianjin by PSR Model

Urban environmental pressure is increasing with acceleration of urbanization and urban ecological situation is not optimistic any more. It's very necessary to conduct ecological security assessment on cities. This paper employed the PSR (pressure-state-response) model and determined the weight of index based on improved analytic hierarchy process (IAHP) and entropy method. Index system of ecological security assessment of Tianjin with time scale from the year 2001 to 2007 was also established. From the evaluation result, the urban ecological security state in Tianjin from 2001 to 2007 was getting better, which can measure situation of ecological security in Tianjin in the past seven years and in order to assist early-warning, management and decision-making of city ecological safety.