Agricultural green and blue water consumption and its influence on the global water system
Agricultural green and blue water consumption and its influence on the global water system
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DOI：
10.1029/2007wr006331
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发表时间：
2008-09-04
影响因子：
5.4
通讯作者：
Schaphoff, Sibyll
中科院分区：
文献类型：
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作者：
Rost, Stefanie;Gerten, Dieter;Schaphoff, Sibyll
本研究量化，空间明确和一致的建模框架（隆德-波茨坦-耶拿管理的土地），全球消费的“蓝”水（从河流，湖泊和含水层中提取用于灌溉）和“绿”水（降水）的灌溉和灌溉农业和非农业陆地生态系统。此外，量化了人类引起的土地覆盖变化和灌溉的个别影响，以评估过去世纪全球农业的总体水文影响。不可再生（化石地下水）和非本地蓝水（e。例如，在一个实施例中，来自改道河流）是从一个模拟，其中这些资源被隐含考虑（IPOT）和模拟，其中他们被忽略（ILIM）之间的差异。结果表明，1971-2000年全球农田耗水量大于7200 km 3/a，分别占作物总耗水量的92%（ILIM）和85%（IPOT）。即使在灌溉农田，35%（ILIM）和20%（IPOT）的水消耗由绿色水组成。另外8155 km 3年（-1）的绿色水消耗在牧场上;另外44，700 km 3年（-1）维持生态系统。蓝水消耗量仅在集中灌溉地区占主导地位，全球范围内估计为636 km 3年（-1）（ILIM）和1364 km 3年（-1）（IPOT），这表明目前几乎一半的灌溉水来自不可再生和非本地来源。土地覆被转换减少了2.8%的全球蒸散量，增加了5.0%（1764公里3年（-1）），而灌溉增加蒸散量高达1.9%，减少排放量至少0.5%（IPOT，1971-2000）。由于气候变化以及全球耕作和灌溉面积的不断增加，不同的水通量表现出相当大的年际和年代际变化。
This study quantifies, spatially explicitly and in a consistent modeling framework (Lund-Potsdam-Jena managed Land), the global consumption of both "blue'' water (withdrawn for irrigation from rivers, lakes and aquifers) and "green'' water (precipitation) by rainfed and irrigated agriculture and by nonagricultural terrestrial ecosystems. In addition, the individual effects of human-induced land cover change and irrigation were quantified to assess the overall hydrological impact of global agriculture in the past century. The contributions to irrigation of nonrenewable ( fossil groundwater) and nonlocal blue water (e. g., from diverted rivers) were derived from the difference between a simulation in which these resources were implicitly considered (IPOT) and a simulation in which they were neglected (ILIM). We found that global cropland consumed > 7200 km 3 year(-1) of green water in 1971-2000, representing 92% (ILIM) and 85% ( IPOT), respectively, of total crop water consumption. Even on irrigated cropland, 35% (ILIM) and 20% (IPOT) of water consumption consisted of green water. An additional 8155 km 3 year(-1) of green water was consumed on grazing land; a further similar to 44,700 km 3 year(-1) sustained the ecosystems. Blue water consumption predominated only in intensively irrigated regions and was estimated at 636 km 3 year(-1) (ILIM) and 1364 km 3 year(-1) ( IPOT) globally, suggesting that presently almost half of the irrigation water stemmed from nonrenewable and nonlocal sources. Land cover conversion reduced global evapotranspiration by 2.8% and increased discharge by 5.0% ( 1764 km 3 year(-1)), whereas irrigation increased evapotranspiration by up to 1.9% and decreased discharge by 0.5% at least (IPOT, 1971-2000). The diverse water fluxes displayed considerable interannual and interdecadal variability due to climatic variations and the progressive increase of the global area under cultivation and irrigation.