Dynamic assessment and early warning of ecological security: a case study of the Yangtze river urban agglomeration

Ecological security is vital to the survival of human beings and critical to the sustainable development of socioeconomic environment. In view of the deficiencies of the static assessment of ecological security, in this paper ,a dynamical evaluation on the ecological security of urban agglomerations is conducted by utilizing an index system developed from the Driving Force-Pressure-State-Response model. Further, an empirical study is carried out for the Yangtze River Urban Agglomeration to explore the ecological security alarms and change rules: Incorporating the statistical data from 2005 to 2017 into the investigation, the combined weight method is applied to calculate the weight of ecological safety over ecological security contribution, and the Moran's I index is implemented to analyze the changes in the spatial pattern. The results show that (1) The ecological security index of the Yangtze River Urban Agglomeration exhibits a smaller fluctuation primarily caused by the transformation of economic development mode, and the overall ecological security has been improved since 2005 from less safe to security level in general. (2) Spatial differences exist between North and South as well as between urban agglomerations, and the overall ecological security is improved due to ecological protection measures and industrial structure adjustment, and (3) The levels of early warning for these cities in the Yangtze River Urban Agglomeration differ, Varying between medium level and severe level. Furthermore, It is also found that human activities greatly impact the ecological security, and the intensity of land development is the greatest threat.