Analysis of the effects of the spatiotemporal distribution of intense rainfall on flood resilience in urban catchments

Study region Ribeirão dos Meninos watershed, located in the São Paulo Metropolitan Region, Brazil, a highly urbanized catchment with a history of severe flooding events. Study focus This study investigates how the spatiotemporal characteristics of intense rainfall influence urban flood resilience. An integrated framework combining hydrological–hydraulic modeling using the Personal Computer Storm Water Management Model (PCSWMM) and multicriteria analysis was applied to 15 rainfall events, classified by peak timing, rainfall-core location, and spatial variability (coefficient of variation, Cv). Resilience was quantified using an entropy-weighted Urban Flood Resilience Index (UFRI) at the sub-catchment scale. New hydrological insights for the region Resilience showed significant variability (0.27–0.84), with upstream areas presenting higher and more stable resilience, while downstream regions were more sensitive to concentrated storms. Some upstream sub-catchments, however, exhibited event-dependent reductions in resilience, revealing hidden vulnerabilities not captured by uniform rainfall approaches. A significant negative correlation between UFRI and Cv indicates that spatially concentrated rainfall reduces resilience. Temporally concentrated events also decreased resilience, whereas more uniform rainfall patterns produced more balanced responses. Overall, spatially concentrated and temporally peaked rainfall events significantly reduce urban flood resilience, highlighting the critical role of rainfall heterogeneity in shaping system response and risk distribution and providing relevant insights for urban flood management and planning.