ABSTRACT

Critical infrastructure provide essential goods and services to communities, supporting the population’s well-being. Their functionality is essential and any interruption or disruption may result in considerable losses and impacts on the economy as well as the well-being of communities. In the case of a damaging event, (inter)dependencies may propagate the impact of failure or reduction of functionality of one infrastructure to other dependent infrastructure, often resulting in widespread disruption and slower recovery. This chapter presents network-based models of interdependent critical infrastructure for regional risk and resilience analysis. Infrastructures are modeled mathematically as networks, extending to civil engineering applications well-established tools of graph theory. Topology and flow-based methods are used to translate the physical damage of the single components into loss or reduction of network functionality and to develop network capacity and demand models. These models are integrated in a time-varying network reliability and resilience analysis to assess the network response in the immediate aftermath of a damaging event and at different times during recovery process, as the network components are repaired. A multi-level heterogeneous network model is used to capture the role of interdependencies and propagate the loss or reduction of functionality across all dependent networks. This chapter applies the presented models to two example testbeds. Results shed light into the role of interdependencies among critical infrastructure.