Cascading Failure - Infrastructures

Infrastructures

Today’s networks are becoming increasingly dependent on one another. Diverse infrastructures such as water supply, transportation, fuel and power stations are coupled together. Owing to this coupling, interdependent networks are extremely sensitive to random failure, and in particular to targeted attacks, such that a failure of a small fraction of nodes from one network can produce an iterative cascade of failures in several interdependent networks. Electrical blackouts frequently result from a cascade of failures between interdependent networks, and the problem has been dramatically exemplified by the several large-scale blackouts that have occurred in recent years. Blackouts are a fascinating demonstration of the important role played by the dependencies between networks. For example, the September 28, 2003 blackout in Italy resulted in a widespread failure of the railway network, health care systems, and financial services and, in addition, severely influenced communication networks. The partial failure of the communication system in turn further impaired the power grid management system, thus producing a negative feedback on the power grid. This example emphasizes how inter-dependence can significantly magnify the damage in an interacting network system. A framework to study the cascading failures between coupled networks based on percolation theory was developed recently.