High-resolution mapping of global surface water and its long-term changes
High-resolution mapping of global surface water and its long-term changes
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DOI：
10.1038/nature20584
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发表时间：
2016-12-15
期刊：
影响因子：
64.8
通讯作者：
Belward, Alan S.
中科院分区：
文献类型：
--
作者：
Pekel, Jean-Francois;Cottam, Andrew;Belward, Alan S.
地表水（内陆和沿海）的位置和持续性既受到气候和人类活动(1)的影响，又影响气候(2,3)、生物多样性(4)和人类福祉(5,6)。记录地表水位置和季节性的全球数据集是根据清单和国家描述(7)、区域数据的统计外推(8) 和卫星图像(9-12) 生成的，但以高分辨率测量长期变化仍然是一个挑战。在这里，我们使用 300 万张 Landsat 卫星图像(13)，以 30 米的分辨率量化了过去 32 年中全球地表水的变化。我们记录水存在的月份和年份、发生变化的地点以及季节性和持久性变化的形式。 1984年至2015年间，近90,000平方公里的永久地表水已经消失，大致相当于苏必利尔湖的面积，尽管其他地方已经形成了覆盖184,000平方公里的新的永久地表水体。所有大陆地区的永久水量均出现净增加，但大洋洲除外，该地区出现了小部分（百分之一）的净损失。尽管气候变化(14)也与此有关，但大部分增加是由于水库蓄水造成的。损失比收益在地域上更加集中。全球永久净水损失的 70% 以上发生在中东和中亚，这与干旱和人类活动有关，包括河流改道或筑坝以及不受管制的取水(15,16)。澳大利亚(17) 和美国(18) 与长期干旱相关的损失也很明显。这个全球一致的、经过验证的数据集表明，可以测量气候变化和气候振荡对地表水发生的影响，并可以收集证据来表明人类活动如何改变地表水。我们预计这些免费数据将改进地表强迫的建模，提供湿地生态交错带（生物群落之间的过渡区域）的状态和变化的证据，并为水管理决策提供信息。
The location and persistence of surface water (inland and coastal) is both affected by climate and human activity(1) and affects climate(2,3), biological diversity(4) and human wellbeing(5,6). Global data sets documenting surface water location and seasonality have been produced from inventories and national descriptions(7), statistical extrapolation of regional data(8) and satellite imagery(9-12), but measuring long-term changes at high resolution remains a challenge. Here, using three million Landsat satellite images(13), we quantify changes in global surface water over the past 32 years at 30-metre resolution. We record the months and years when water was present, where occurrence changed and what form changes took in terms of seasonality and persistence. Between 1984 and 2015 permanent surface water has disappeared from an area of almost 90,000 square kilometres, roughly equivalent to that of Lake Superior, though new permanent bodies of surface water covering 184,000 square kilometres have formed elsewhere. All continental regions show a net increase in permanent water, except Oceania, which has a fractional (one per cent) net loss. Much of the increase is from reservoir filling, although climate change(14) is also implicated. Loss is more geographically concentrated than gain. Over 70 per cent of global net permanent water loss occurred in the Middle East and Central Asia, linked to drought and human actions including river diversion or damming and unregulated withdrawal(15,16). Losses in Australia(17) and the USA(18) linked to long-term droughts are also evident. This globally consistent, validated data set shows that impacts of climate change and climate oscillations on surface water occurrence can be measured and that evidence can be gathered to show how surface water is altered by human activities. We anticipate that this freely available data will improve the modelling of surface forcing, provide evidence of state and change in wetland ecotones (the transition areas between biomes), and inform water-management decision-making.