Urban agglomeration ecological risk transfer model based on Bayesian and ecological network

Urban ecological risk thinking and policies should address larger-scale and consider urban dependence and impacts on distant populations and ecosystems. In urban agglomeration perspective, some researchers examined the spatial heterogeneous distribution of ecological risk at different cities, but ignored the interaction effect between two cities. In this study, a Bayesian and Ecological Network model is used to simulate the ecological risk transfer process between two cities under (1) air pollution transmission pathway, (2) water pollution transmission pathway and (3) economic trade transmission pathway, and to test the ecological risk promotion degree after considering the risk transferring from other cities. Ecosystem services are adopted as the assessment endpoint of ecological risk. Taking the Pearl River Delta urban agglomeration as an example, the results show that, without considering the risk transferring in the urban agglomeration, the top three high risk cities are Dongguan, Zhongshan and Shenzhen. Risk transferring between two cities greatly increases the urban comprehensive risk probabilities, especially in Zhaoqing (134% increase rate), Zhuhai (73.0%) and Guangzhou (70.4%). Guangzhou and Shenzhen are both disseminators and victims of ecological risks in urban agglomerations. The Bayesian and ecological network model can support the decision-making process used for ecological risk prevention and ecosystem services improvement.