Wetland degradation risk assessment method and its application: a case study of Tianjin City

Due to the acceleration of the climate change and human activities, the wetlands, which are important ecosystem on the earth, are continuously appropriated, damaged and even disappearing. It is thus very urgent and necessary to establish a reliable evaluation model for the wetlands degradation. Based on the theory of regional ecological risks, a multi-index evaluation system including 22 indexes was established from the two aspects of stress degree and degradation degree, and the risks of wetland degradation in Tianjin from 1990 to 2015 was assessed. The results showed that the risk of wetland degradation in Tianjin City showed a trend of decreasing first and then increasing due to the fluctuation change of stress degree and the increase of degradation degree of the wetland itself. The value of degradation risk in 2015 increased by 10.08% compared to 1990. And the risk value of the areas with originally low risk of wetland degradation presented a phenomenon of rapid increase of risk. Therefore, it is urgent to formulate more strict policies and build up a better management system to strengthen the protection and restoration of wetlands in Tianjin City.