Modeling Societal Consequences of Damage Cascades in Critical Infrastructures to Quantify Resilience Benefits of Nature-Based Solutions

Modern societies rely on intricate critical infrastructure networks to satisfy essential needs. Quantifying and characterizing their resilience is crucial for pinpointing vulnerabilities that may interrupt operations and for judging mitigation measures that enhance crisis preparedness, prevention, response, or recovery. Nature-based solution (NBS) approaches have recently attracted attention in this context. To evaluate their efficacy against adverse events under varied initial conditions and disaster intensities, robust modeling frameworks are necessary. Prior studies introduced a graph-based modeling framework that offers a comprehensive view of the resilience of critical infrastructures during natural disasters, notably flash floods, via simulations of cascading failures and subsequent recovery phases. Based on this foundation, this paper presents an approach to simulate the societal consequences of such failures to widen the understanding of disaster consequences. Key services provided by critical infrastructures are identified and a process model is developed that captures the local population's demand for each service, e.g., hospital treatments or cash provision by ATMs. Once a natural disaster occurs, these demands may increase while the critical infrastructures are impaired by disaster effects. In consequence, service-specific backlogs emerge that depend on the disaster and local vulnerabilities. Inspecting exemplary simulation results, this paper shows how such estimations can be used to assess NBS mitigated and unmitigated floods.

Keywords: resilience quantification, societal consequences, cascading failure modeling, critical infrastructure, natural disasters, nature-based solutions.