HydroUrbanMap (HUM): Delineating city boundaries for global urban water scarcity assessment

Rapid urbanization has increased water demand in cities worldwide, and global urban water scarcity assessments should be carried out at city-scale. We developed the Hydro Urban Map (HUM), a global dataset of city boundaries for 1,604 cities at 5 arcmin resolution. HUM delineates city masks and integrates information relevant to urban water supply and drainage. By combining multiple geospatial datasets, HUM identifies the uppermost and lowermost grid cells along each city’s main river, which are designated as the city water inlet and city water outlet, respectively. In addition, HUM identifies potential aqueduct source locations by selecting grid cells with sufficient annual streamflow in the vicinity of each city mask.