An Agent-based Modeling Framework for Sociotechnical Simulation of Water Distribution Contamination Events

In the event that a bacteriological or chemical toxin is intro- duced to a\nwater distribution network, a large population of consumers may become exposed\nto the contaminant. A contamination event may be poorly predictable dynamic\nprocess due to the interactions of consumers and utility managers during an\nevent. Consumers that become aware of a threat may select protective actions\nthat change their water demands from typical demand patterns, and new hydraulic\nconditions can arise that differ from conditions that are predicted when\ndemands are considered as exogenous inputs. Consequently, the movement of the\ncontaminant plume in the pipe network may shift from its expected trajectory. A\nsociotechnical model is developed here to integrate agent-based models of\nconsumers with an engineering water distribution system model and capture the\ndynamics between consumer behaviors and the water distribution system for\npredicting contaminant transport and public exposure. Consumers are simulated\nas agents with behaviors defined for water use activities, mobility,\nword-of-mouth communication, and demand reduction, based on a set of rules\nrepresenting an agents autonomy and reaction to health impacts, the\nenvironment, and the actions of other agents. As consumers decrease their water\nuse, the demand exerted on the water distribution system is updated; as the\nflow directions and volumes shift in response, the location of the contaminant\nplume is updated and the amount of contaminant consumed by each agent is\ncalculated. The framework is tested through simulating realistic contamination\nscenarios for a virtual city and water distribution system.\n