Simulation model for urban water dissipation

Rapid urbanization have resulted in increasing water supply in urban areas and further led to more water dissipation from urban water uses. When calculating water dissipation, traditional hydrological models only considered evaporation from precipitation, usually ignoring the dissipation due to human water consumption. In order to analyze the urban water consumption process and better understand the urban water dissipation (UWD) mechanism, the UWD calculation model was developed based on the observation of the urban water consumption process and the categorization of UWD units. According to the results from statistical analysis, experiments and the mathematical model, the UWD of one region in Beijing in 2014 was estimated as 820.0 mm, which was significantly higher than that from the traditional hydrological model (494.0 mm averaged over many years). The results showed that the contributions of water dissipation from the green land, building, hardened ground and water surface were respectively 40.58%, 38.70% (including 31.22% from human activities and 7.48% from building roofs), 18.32% and 2.40%. It was concluded that water dissipation inside buildings was one main component of artificial water consumption and was non-negligible for the computation of the total UWD. The quantity of water dissipation of a building was proportional to the number of floors and residents in the building.