EMS Publication

A new publication in the journal Environmental Modelling & Software (Srivastava et al., 2026) describes a new model, PSI-Cascade, to couple stormwater flooding and power outages for the analysis of cascading infrastructure failures, with an application to Phoenix, Arizona. Congratulations to the authors associated with the Center for Hydrologic Innovations!

Abstract: Urban infrastructure is typically designed in isolation, neglecting system interdependencies and the effects of spatiotemporal variability of climate forcings across systems. Here, these limitations are addressed by developing the PSI-Cascade Python-based framework, which simulates cascading failures from power to stormwater infrastructure under high-resolution space-time wind gust and precipitation forcings. PSI-Cascade couples open-source, spatially explicit stormwater and power infrastructure models and represents cascading failures on stormwater pumping stations caused by wind-induced power outages through user-defined fragility curves, linking wind gusts with the transmission line failure probability. Using Phoenix, AZ as a case study, it is shown that PSI-Cascade adequately captures the spatiotemporal variability of documented street flooding, particularly around pumping stations that likely stopped operating due to wind-triggered power outages. The case study also highlighted the importance of parameterizing the fragility curves based on local failures. The PSI-Cascadeframework is a valuable tool for increasing urban flood resilience.