Ecological risk and resilient regulation shifting from city to urban agglomeration: A review

The study of urban resilience from a risk perspective is crucial for reducing urban ecological risks and achieving sustainable development in cities. However, the large scale of urban areas (urban agglomeration) poses challenges to maintaining resilience. Under the influence of the inter-city relationship, urban ecological risk transmission process and the relationship with resilience have the characteristics of nonlinear network transmission. Current relative researches ignored the transmission effect on the ecological risk complexity and relationship between ecological risk and resilience. To fill this gap, it is necessary to explore innovative methods and develop a theoretical framework for studying ecological risk and resilience regulation in urban agglomerations. This study proposes a new ecological risk and resilient regulation framework for urban agglomeration. This framework should encompass ecological risk transmission, resilience regulation and optimization, and collaborative management. The results indicate several important trends: 1) Future research should integrate urban interconnectivity into ecological risk assessment and urban network structure resilience assessment. 2) Ecological risks in urban agglomerations exhibit cumulative and infectious characteristics. 3) Factors such as water resource sharing, air pollution diffusion, ecological protection and restoration, and geographic information sharing contribute to the complexity of ecological risk and resilience research in urban agglomerations compared to individual cities. 4) The proposed new framework enables comprehensive representation of multi-source risk superposition and multi-risk levels, aiming to enhance the resilience of urban agglomerations.