Department of Water Engineering and Management, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Proc Natl Acad Sci U S A. 2012 Feb 28;109(9):3232-7. doi: 10.1073/pnas.1109936109. Epub 2012 Feb 13.
This study quantifies and maps the water footprint (WF) of humanity at a high spatial resolution. It reports on consumptive use of rainwater (green WF) and ground and surface water (blue WF) and volumes of water polluted (gray WF). Water footprints are estimated per nation from both a production and consumption perspective. International virtual water flows are estimated based on trade in agricultural and industrial commodities. The global annual average WF in the period 1996-2005 was 9,087 Gm(3)/y (74% green, 11% blue, 15% gray). Agricultural production contributes 92%. About one-fifth of the global WF relates to production for export. The total volume of international virtual water flows related to trade in agricultural and industrial products was 2,320 Gm(3)/y (68% green, 13% blue, 19% gray). The WF of the global average consumer was 1,385 m(3)/y. The average consumer in the United States has a WF of 2,842 m(3)/y, whereas the average citizens in China and India have WFs of 1,071 and 1,089 m(3)/y, respectively. Consumption of cereal products gives the largest contribution to the WF of the average consumer (27%), followed by meat (22%) and milk products (7%). The volume and pattern of consumption and the WF per ton of product of the products consumed are the main factors determining the WF of a consumer. The study illustrates the global dimension of water consumption and pollution by showing that several countries heavily rely on foreign water resources and that many countries have significant impacts on water consumption and pollution elsewhere.
本研究以高空间分辨率量化和绘制了人类的水足迹（WF）。它报告了雨水（绿 WF）和地表水及地下水（蓝 WF）的消耗利用情况以及受污染的水量（灰 WF）。水足迹是从生产和消费两个角度按国家进行估算的。根据农产品和工业商品的贸易情况估算了国际虚拟水流量。1996-2005 年期间，全球年平均水足迹为 9087 亿立方米/年（74%为绿 WF，11%为蓝 WF，15%为灰 WF）。农业生产贡献了 92%。全球水足迹的约五分之一与出口生产有关。与农产品和工业产品贸易有关的国际虚拟水流量总量为 2320 亿立方米/年（68%为绿 WF，13%为蓝 WF，19%为灰 WF）。全球平均消费者的水足迹为 1385 立方米/年。美国消费者的水足迹平均值为 2842 立方米/年，而中国和印度的普通公民的水足迹分别为 1071 和 1089 立方米/年。粮食产品的消费对普通消费者水足迹的贡献最大（27%），其次是肉类（22%）和奶制品（7%）。消费的产品数量和模式以及产品每吨的水足迹是决定消费者水足迹的主要因素。本研究通过展示几个国家严重依赖外国水资源以及许多国家对其他地方的水资源消耗和污染产生重大影响，说明了水资源消耗和污染的全球性。
