Calculating the water dissipation of buildings in urban areas based on global nighttime light data

Abstract Urban water dissipation is increasing gradually as urbanization progresses. Urban water dissipation mainly includes the dissipation of water in buildings and natural water evapotranspiration. Previous studies have mainly focused on calculating natural evapotranspiration in urban areas and have overlooked the dissipation of water in buildings under the influence of strong human-related water use activities. In this paper, the concept of building water dissipation (BWD) was proposed to describe the phenomenon that water dissipation occurs inside buildings. Moreover, a BWD calculation model was established and applied to calculate global building water dissipation. To reveal the specific water dissipation inside buildings, it is necessary to obtain the urban building floor area first. This paper proposed a new method to calculate the urban building floor area based on global nighttime light data obtained from NPP-VIIRS. Taking the floor area results into the BWD calculation model, the global building water dissipation in urban areas was found to be 127 billion m3 in 2015. The vast building water dissipation that occurs in urban areas mostly results from rapidly developing economies and intense human activities. The results provide a basic understanding of the nexus between water resources and the energy-heat island effect in urban areas.