Stochastic model applied to water demand management in Brazil

Abstract

The increasing scarcity of water sources near urban areas, coupled with urbanization and population growth, necessitates the development of solutions that optimize water demand management, which entails a more accurate estimation of consumption patterns and implementing measures that promote the rational use of water. A stochastic residential water demand model was built based on the superposition of pulses of constant intensity and variable arrival time and duration applied to the microcomponent consumption at a 1-minute resolution, reflecting the aggregate system contributions to the total instantaneous demand. The model can support the planning of water supply systems (WSSs) and was calibrated using data from Brazilian institutes combined with a literature review of statistical data on users and end uses of water in Brazilian dwellings. Innovatively, it proposes using water demand forecasting to apply demand management measures evaluating the replacement of conventional devices for water-saving ones by analyzing hydrographs of 50–50,000 households, in addition to detailing the influence of the K2 peak factor. The results demonstrated a new water consumption profile with about a 40% reduction in water demand. A new equation for K2 is proposed as an alternative to estimate the demand for small populations fittingly. HIGHLIGHTS The model can support the planning of water supply systems (WSS).; From its use, it is possible to obtain essential characteristics for the dimensioning and operation of supply networks, such as maximum, average, and minimum flows, peak hours, per capita consumption, and consumption per appliance, among others.; A new formulation for the peak coefficient is available from the data used in the model.;

Keywords

• computational model
• demand management
• efficient appliance
• end uses