Abstract
Critical infrastructure (CI) networks—such as power, water, and transportation—are increasingly exposed to compound hazards, where natural events like flooding coincide with cyber-physical attacks. Traditional resilience assessments often treat these threats in isolation, underestimating cascading failures and interdependencies. This study proposes a multi-dimensional resilience assessment framework that integrates flood risk modeling, cyber threat analysis, and network interdependency metrics. Using a realistic regional case study of an urban area in Europe, we simulate compound flood-cyber scenarios and evaluate resilience across three phases: absorption, adaptation, and recovery. Results indicate that compound hazards reduce system resilience by up to 40% compared to single hazards, with cyber disruptions amplifying flood-induced failures in power and water networks. The framework identifies critical nodes where targeted hardening yields disproportionate resilience gains. We also present a cyber-physical resilience index (CPRI) to quantify performance under combined stressors. Our findings underscore the need for integrated planning and cross-sector coordination to enhance CI resilience in an era of escalating climate and cyber risks. The methodology offers a scalable tool for policymakers and infrastructure operators to prioritize investments and improve preparedness.