Simulation Study to Evaluate Temporal Aggregation and Variability of Stochastic Water Demands on Distribution System Hydraulics and Transport

Abstract

AbstractAs utilities move toward more detailed hydraulic and water quality network models, the potential for the stochastic nature of consumptive demands having an effect on transport characteristics increases. A nonhomogeneous Poisson rectangular pulse model (PRPsym) was used to generate stochastic water demands aggregated at 1-min, 10-min, and 1-h time steps for a small skeletonized network and a large all-pipe network; results were then linked with EPANET to simulate the impacts of water-demand variability on the underlying transport and water quality. In general, the impacts of temporal aggregation—as represented by flow rate and concentration variability and arrival times—increased as the evaluations moved from the main trunk lines toward dead-end nodes or pipes. More specifically, analysis of a Monte Carlo ensemble of results demonstrated that (1) a 10-min temporal aggregation captured most of the arrival time variability relative to the 1-min aggregation step; (2) hourly demand variability (e.g., f...