Infrastructure Links Amplify Impacts

The authors develop a modelling framework to assess how natural hazards, intensified by climate change, propagate cascading failures across interdependent critical infrastructures. The framework is applied to interdependent power and water networks in North Italy under historical wind-gust conditions and under climate projections following Representative Concentration Pathways 4.5 and 8.5. The authors find that climate change primarily alters inoperability by increasing the frequency of extreme wind gusts rather than substantially shifting their typical intensity, and that its effects on cascading disruption between the two networks are scenario-dependent and non-monotonic, with the largest increase in cumulative water network inoperability occurring under late-century RCP 8.5 conditions. The analysis further identifies the transmission lines most critical to cascading failure across the system and shows that retrofitting these components reduces mean inoperability across all scenarios, while partial decoupling between the power and water networks, through backup generation capacity, further attenuates cascading effects. The authors conclude that the framework, though demonstrated on wind-gust hazards, is hazard-agnostic and can be transferred to other hazard types and infrastructure pairs, providing insights to inform the design of prevention and mitigation strategies for interdependent infrastructure systems under climate change.