An Agent-Based Modeling Approach to Simulate the Dynamics of Water Supply and Water Demand

Abstract

Water resources management requires an insightful balance between water demand and water supply. US water supply is at risk of shortage due to population growth, land use changes, climate change, and water use behaviors of customers. Long-term water supply planning is conventionally based on projections of population growth and demands; however, the sustainability of water resources depends on the dynamic interactions among the environmental, technological, and social characteristics of the water system and local population. This research develops a sociotechnical model to simulate the interactions among the social and engineering systems. An agent-based model (ABM) is used to simulate households and water-use behaviors and is coupled with a set of technical models, including climate change projections, a hydrological watershed model, and a water reservoir model. The ABM framework simulates population growth as an increase in the number of household agents, which affects the water supply and demand balance through increasing demands. Household agents increase irrigation demands due to climate change and decrease indoor demands as they adopt low-flow appliances. Agents also respond to drought restrictions by limiting their use of water for outdoor application. The effects of these actions on the reservoir storage are simulated using engineering models and data describing the climatological and hydrological conditions of the watershed. The ABM framework is developed and demonstrated for the Raleigh, NC, water supply system, which withdraws water from the Falls Lake Reservoir. The model is tested against historic data (1983-2013) and is used to explore the effectiveness of policies for the period 2013-2033. Conservation programs and drought restrictions are simulated and to evaluate the need to develop new water source in the future. The ABM framework facilitates simulations that generate new insight about the dynamics involved in the sustainability of water supply and demands. 1806 World Environmental and Water Resources Congress 2014: Water without Borders © ASCE 2014