Twente Water Centre, University of Twente , P.O. Box 217, 7500 AE Enschede, The Netherlands.
Environ Sci Technol. 2015 Nov 3;49(21):12860-8. doi: 10.1021/acs.est.5b03191. Epub 2015 Oct 22.
This is the first global assessment of nitrogen-related water pollution in river basins with a specification of the pollution by economic sector, and by crop for the agricultural sector. At a spatial resolution of 5 by 5 arc minute, we estimate anthropogenic nitrogen (N) loads to freshwater, calculate the resultant gray water footprints (GWFs), and relate the GWFs per river basin to runoff to calculate the N-related water pollution level (WPL) per catchment. The accumulated global GWF related to anthropogenic N loads in the period 2002-2010 was 13×10(12) m3/y. China contributed about 45% to the global total. Three quarters of the GWF related to N loads came from diffuse sources (agriculture), 23% from domestic point sources and 2% from industrial point sources. Among the crops, production of cereals had the largest contribution to the N-related GWF (18%), followed by vegetables (15%) and oil crops (11%). The river basins with WPL>1 (where the N load exceeds the basin's assimilation capacity), cover about 17% of the global land area, contribute about 9% of the global river discharge, and provide residence to 48% of the global population.
这是首次对流域内与氮相关的水污染进行的全球性评估，具体说明了经济部门和农业部门的污染情况。我们以 5 乘 5 弧分的空间分辨率估算了向淡水中人为输入的氮（N）负荷，计算了由此产生的灰色水足迹（GWF），并将流域内的 GWF 与径流量相关联，以计算每个汇水区的与 N 相关的水污染水平（WPL）。2002 年至 2010 年期间，与人为 N 负荷相关的全球累计 GWF 为 13×10(12) m3/y。中国的贡献约占全球总量的 45%。四分之三的 GWF 与 N 负荷来自于分散源（农业），23%来自于国内点源，2%来自于工业点源。在农作物中，谷类生产对与 N 相关的 GWF 的贡献最大（18%），其次是蔬菜（15%）和油料作物（11%）。WPL>1（即 N 负荷超过流域的同化能力）的流域覆盖了约 17%的全球陆地面积，贡献了约 9%的全球河流径流量，为全球 48%的人口提供了居住地。
