Exposing inequitable risk estimation of emergency service disruptions during urban floods

Abstract Emergency service (ES) disruption is a major impact of urban flooding. As a critical safety and health safeguard, ES disruption risk mitigation must consider the equity of risk across populations with varying social vulnerability. A key prerequisite in this equitable risk management endeavor is the estimation of risk distributions and their spatial relationship to vulnerability. Assuming estimated risk is a good indicator of the real risk levels, extant research and practice overlook the potential biases in risk estimation errors regarding vulnerability. Greater risk underestimation for more vulnerable populations could lead to inequitable risk estimation and less effective risk mitigation. By implementing the routing-based risk estimation and investigating the error against a real-world ES dataset, we found evidence of inequitable risk underestimation and analyzed the underlying urban dynamics for the inequity. The results could deepen our understanding of ES flood risk inequity and promote more accurate and equitable estimation method development.