Contrasting water footprints of cities in China and the United States

摘要: We examined production and consumption patterns of freshwater, a critical ecosystem service, for selected cities in China the United States. Ecosystem freshwater varies with precipitation evapotranspiration rates, which are affected by climate, topography, vegetation cover, soil characteristics. Urban demand is spatially distributed due to location cities, variation per-capita usage, urban population size. To link heterogeneous service rates we calculated ecological footprints (HEF) land area required provide needs. asked, what determines footprint States China? Are same factors operating fashion both countries? Our results show strong interaction between size local resource determining footprint. These suggest extending I=PAT identity include term describing productivity determination human impact. By using methodology this manner, can address questions concerning relationship social systems identify urban-scale constraints sustainable withdrawal particular service. D 2005 Elsevier B.V. All rights reserved.