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
water distribution network, a large population of consumers may become exposed
to the contaminant. A contamination event may be poorly predictable dynamic
process due to the interactions of consumers and utility managers during an
event. Consumers that become aware of a threat may select protective actions
that change their water demands from typical demand patterns, and new hydraulic
conditions can arise that differ from conditions that are predicted when
demands are considered as exogenous inputs. Consequently, the movement of the
contaminant plume in the pipe network may shift from its expected trajectory. A
sociotechnical model is developed here to integrate agent-based models of
consumers with an engineering water distribution system model and capture the
dynamics between consumer behaviors and the water distribution system for
predicting contaminant transport and public exposure. Consumers are simulated
as agents with behaviors defined for water use activities, mobility,
word-of-mouth communication, and demand reduction, based on a set of rules
representing an agents autonomy and reaction to health impacts, the
environment, and the actions of other agents. As consumers decrease their water
use, the demand exerted on the water distribution system is updated; as the
flow directions and volumes shift in response, the location of the contaminant
plume is updated and the amount of contaminant consumed by each agent is
calculated. The framework is tested through simulating realistic contamination
scenarios for a virtual city and water distribution system.
