Assessment of subsystem interactions and coupling coordination in flood resilience evaluation: Comparative analysis and policy recommendations

This study investigates how regional variations in socioeconomic status, land use patterns, and critical infrastructure affect flood resilience by distinguishing between areas experiencing mild and severe flooding using the Flood Resilience Index (FRI). The FRI framework conceptualizes flood resilience as an integrated system comprising three subsystem indicators: hazard, exposure, and sensitivity. To understand flood resilience dynamics, this research emphasizes subsystem interactions through coupling coordination analysis. Results demonstrate that exposure is the primary determinant of FRI severity, while hazard drives FRI temporal variations. Sensitivity exhibits lesser overall impact but plays a relatively larger role in mildly flooded areas. Autocorrelation analysis confirms exposure and hazard as dominant indicators, with exposure achieving autocorrelation coefficients of 0.98 in non-urban areas and 0.96 in urban areas. In non-urban regions, topography-induced water retention prolongs exposure duration, contributing to sustained vulnerability. The study introduces an evaluation framework using coupling coefficient (Cn) analysis to quantify subsystem interactions. Findings reveal that severe flooding areas exhibit substantially lower FRI scores (minimum 0.18 in urban areas) due to prolonged flood durations and significant infrastructure damage, whereas mild flooding areas demonstrate faster recovery with socioeconomic resilience playing a more influential role. Critical infrastructure disruptions amplify FRI impacts, with 39 of 42 analysis units showing increased vulnerability when infrastructure factors are incorporated. These insights advance understanding of subsystem interdependencies and provide a robust foundation for developing targeted disaster prevention and resilience enhancement strategies across diverse urban and non-urban environments.