Interoperating Infrastructures in Emergencies

The great challenge in handling the security and resilience in emergency situations is that threats will typically affect more than one infrastructure. A fire is not only a direct hazard for people but it will also short the electrical system, cutting off the lights and possibly the communications and sensor infrastructure and even create more fires. The Tsunami in Japan in 2011 flooded the nuclear reactors but also cut of the pumps that were designed to respond to any flooding situations. This paper is part of a project that addresses these cascaded failures and studies them via simulation. To provide some quantitative estimates of the effect of such cascaded threats, we use the Distributed Building Evacuation Simulator (DBES) to represent the effect of a hazard (in this case a fire) which destroys the sensor system which is used to compute the best advice given to people that are evacuated during the fire. Our simulations compare the situation when the sensor system is intact, and also when it is compromised. As expected, some results highlight the poor overall system performance when the underlying infrastructures are damaged. However, in some scenarios, the degraded system appears to perform as well as the intact one. An analysis into the fault-tolerance of the system leads to some design guidelines which can be applied to design systems fault-tolerant systems.