Graduate Program of Environmental Engineering, Federal University of Santa Catarina, Florianopolis, Brazil.
Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianopolis, Brazil.
Nat Commun. 2022 Sep 1;13(1):5136. doi: 10.1038/s41467-022-32580-x.
Increasing floods and droughts are raising concerns of an accelerating water cycle, however, the relative contributions to streamflow changes from climate and land management have not been assessed at the continental scale. We analyze streamflow data in major South American tropical river basins and show that water use and deforestation have amplified climate change effects on streamflow extremes over the past four decades. Drying (fewer floods and more droughts) is aligned with decreasing rainfall and increasing water use in agricultural zones and occurs in 42% of the study area. Acceleration (both more severe floods and droughts) is related to more extreme rainfall and deforestation and occurs in 29% of the study area, including southern Amazonia. The regionally accelerating water cycle may have adverse global impacts on carbon sequestration and food security.
日益增多的洪水和干旱引发了人们对加速水循环的担忧，然而，在大陆尺度上，还没有评估气候和土地管理对径流量变化的相对贡献。我们分析了南美洲主要热带河流流域的径流量数据，结果表明，在过去四十年中，水的利用和森林砍伐加剧了气候变化对极端径流量的影响。在研究区域的 42%，干旱（洪水减少，干旱增多）与农业区降雨量减少和用水量增加相一致。在研究区域的 29%，包括南亚马孙地区，加速（更严重的洪水和干旱）与更极端的降雨和森林砍伐有关。区域性加速的水循环可能会对全球的碳封存和粮食安全产生不利影响。
