Wiley Handbook of Science and Technology for Homeland Security, 4 Volume Set

ANALYSIS OF CASCADING INFRASTRUCTURE FAILURES

IAN DOBSON

University of Wisconsin-Madison, Madison, Wisconsin

1 SCIENTIFIC OVERVIEW

Cascading failure is the primary mechanism by which an attack or accident of limited scale can yield a major and widespread failure of networked infrastructures. For example, disabling a limited number of components of an electric power grid can induce a cascade of failures leading to a widespread blackout, and this blackout can lead to further failures in other infrastructures, such as transportation, communication, and water supply. The characteristic feature of cascading failure is that a series of failures weakens the system and makes further failures increasingly more likely as the failures become widespread. Cascading failure is of interest to terrorists because a modest attack on a suitably chosen set of system components can propagate via cascading failure to become a widespread failure that is much more visible and destructive. Strategies of preventing and deterring an attack need to be augmented with strategies of limiting the propagation of infrastructure failures consequent to the attack.

We think of cascading failure as having some initial failures that are followed by the propagation of a series of further failures. The failures may propagate within a single infrastructure or between infrastructures [1, 2]. The initial failures can arise from different causes, such as terrorism, sabotage, errors, accidents, weather, or system overload ...