Towards dynamic resilience from static control of urban rainfall-induced pollution: a multi-stress pathway framework for ecological infrastructure

Urban rainfall-induced pollution is an increasingly severe global challenge. Although ecological infrastructure (EI) is widely used, its effectiveness remains uncertain due to the lack of resilience assessment methods. By analyzing 133 sponge city projects and six-year monitoring data from Wuxi’s Binhu District, one of the National Demonstration Sponge Cities in China, we identified three dominant, yet distinct, stress pathways to EI failure: structural limit from volume capture ratio of annual rainfall (VCR), fatigue from consecutive wet days (CWD), and overload from heavy rainfall frequency (R_{P = 60%}). This tripartite mechanism exposes a critical flaw in the prevailing static design paradigm, which primarily addresses single-event rainfall. We therefore propose a Multi-Stress Pathway Resilience Framework that quantifies EI vulnerability across these pathways. Results show that enhancing CWD resistance offers the greatest resilience potential. As CWD and R_{P = 60%} threaten sponge cities across China’s climate zones, we recommend climate-adaptive design, stress adjustment, and dynamic management to advance urban water resilience. This study advocates for a fundamental transition from static control standards to dynamic, pathway-specific resilience management, charting a course for next-generation EI.