The cascade failure model under ecological network is effective for quantifying the resilience of urban regions

Abstract

Human activities and natural disasters degrade urban ecosystems and cause ecological fragmentation at regional scale. It is therefore necessary to create or rehabilitate useful linkages between ecological spaces. Although ecosystem resilience is receiving increasing attention, most studies focus on the spatiotemporal changes of alternative indicators of ecosystem resilience, without considering the changes in the structure and function of internal ecological nodes. Therefore, this study presents a novel research framework that uses cascade failure model based on the ecological network (EN) to evaluate the resilience of typical urban areas. The framework combines “importance-vulnerability” scored ecological sources identification with minimum cumulative resistance simulation to quantitatively characterize the urban region as an EN and assesses the resilience of the urban EN using a capacity-load cascade failure model. The framework was tested in the Xi'an metropolitan region in China resulted in the regional EN with 191 nodes and 571 edges. It was found that the EN of the Xi'an metropolitan region was relatively stable. The network will completely break down only when the node failure rate exceeds 85 %. The framework we propose offers a novel and powerful approach for policymakers to plan for the conservation and development of ecological infrastructure and land uses in urban region context.