Allocating countermeasures to defend water distribution systems against terrorist attack

Water distribution networks are critical infrastructure systems that are vulnerable to terrorist attack. Water utility management has the goal of protecting public health by allocating countermeasures, including security equipment and personnel, as a first line of defense. A malevolent actor may select an attack location, however, using a set of unknown priorities that include performance and susceptibility criteria. This research develops a multi-agent framework to simulate the attack and defense of a distribution system to analyze security resource allocation strategies for protecting against chemical contamination events. A single period attacker-defender game is simulated, in which an attacker seeks to contaminate a system node with high attack utility, and a group of defenders seeks to minimize the public health impact from intentional attack. Terrorist agent decisions are simulated using a multi-attribute utility function, and multiple cases are constructed to simulate alternative rankings of criteria. The water utility manager agent assigns security personnel and deterrent security equipment to nodes using one of three security resource allocation strategies. The agent-based modeling framework is applied to simulate attack and defense for a virtual municipality, D-town. Strategies are evaluated based on the number of consumers exposed to a critical dose when a contaminant is released.