Global water availability boosted by vegetation-driven changes in atmospheric moisture transport
Global water availability boosted by vegetation-driven changes in atmospheric moisture transport
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DOI：
10.1038/s41561-022-01061-7
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发表时间：
2022-10-31
影响因子：
18.3
通讯作者：
Piao, Shilong
中科院分区：
文献类型：
--
作者：
Cui, Jiangpeng;Lian, Xu;Piao, Shilong
地表水的有效性，即降雨量减去蒸散量，可能会受到植被变化的影响。这些影响可以是局部的，这是由于蒸散和降水的改变，也可以是非局部的，因为大气水分输送的变化。然而，植被变化对下风区可用水的遥相关仍然很少受到观测的限制。通过将当地降水量的测量与一个新的水文加权叶面积指数联系起来，我们证明了在2001-2018年期间，植被变化以0.26 mm yr(-2)的速度增加了全球可用水。关键的是，这一增长缓解了最近观察到的全球水资源供应下降的约15%。水可获得性的增加是由于全球53%以上的陆地表面的降雨量相对于蒸散量的增加更大。我们还量化了全球陆地地区任何给定地点区域植被增加的潜在水文影响。我们发现，在接近45%的陆地表面，增强的植被对当地和顺风向水的有效性都是有利的，而在其他地方，主要是在缺水或高海拔地区，这是不利的。我们的结果突出了刻意的植被变化，如植树造林计划，对超出地方和区域尺度的水资源的潜在强烈影响。
Surface-water availability, defined as precipitation minus evapotranspiration, can be affected by changes in vegetation. These impacts can be local, due to the modification of evapotranspiration and precipitation, or non-local, due to changes in atmospheric moisture transport. However, the teleconnections of vegetation changes on water availability in downwind regions remain poorly constrained by observations. By linking measurements of local precipitation to a new hydrologically weighted leaf area index that accounts for both local and upwind vegetation contributions, we demonstrate that vegetation changes have increased global water availability at a rate of 0.26 mm yr(-2 )for the 2001-2018 period. Critically, this increase has attenuated about 15% of the recently observed decline in global water availability. The water availability increase is due to a greater rise in precipitation relative to evapotranspiration for over 53% of the global land surface. We also quantify the potential hydrological impacts of regional vegetation increases at any given location across global land areas. We find that enhanced vegetation is beneficial to both local and downwind water availability for similar to 45% of the land surface, whereas it is adverse elsewhere, primarily in water-limited or high-elevation regions. Our results highlight the potential strong effects of deliberate vegetation changes, such as afforestation programmes, on water resources beyond local and regional scales.