Alteration of River Flow and Flood Dynamics by Existing and Planned Hydropower Dams in the Amazon River Basin
Alteration of River Flow and Flood Dynamics by Existing and Planned Hydropower Dams in the Amazon River Basin
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DOI：
10.1029/2021wr030555
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发表时间：
2022-05-01
影响因子：
5.4
通讯作者：
Pokhrel, Yadu
中科院分区：
文献类型：
--
作者：
Chaudhari, Suyog;Pokhrel, Yadu
水电大坝由于其有害的社会环境影响而受到越来越多的全球关注。这种关注导致了对水库运行对河流流量影响的研究增加；然而，对水电大坝对不同水文特征的复合影响缺乏全面的认识，特别是对亚马逊河等水电开发正在兴起的大流域。在这里，我们机械地量化了现有水坝的历史影响，以及1981-2019年期间亚马逊流域范围内现有和计划中的水坝集体运行的潜在影响。我们以最近开发的高分辨率（3-arcmin，类似于5公里）河流-洪泛平原-水库模型为基础，cama -洪水-大坝，该模型经过增强，可以真实地模拟考虑最大发电量的水电站大坝运行。洪水模拟进一步缩小到3弧秒（类似于90米）分辨率，以研究大坝对整个流域精细尺度洪水动态的影响。结果表明，现有的水坝大大改变了下游河流的流量和整个亚马逊河流域的洪水模式。具体来说，亚马逊流域的大型水坝，包括新古、马德拉和托坎廷斯，已经改变了下游河流的流量幅度，其幅度高达3个数量级。此外，现有和计划中的水坝的集体运作可能会越来越多地改变河流的流动模式，导致亚马逊河主干许多地区的洪水持续时间减少10%。我们的研究结果为大型水电大坝水文影响的严重性提供了定量证据，对亚马逊河流域乃至全球水电的可持续运行和发展具有重要意义。
Hydropower dams have received increased global attention due to their detrimental socioenvironmental ramifications. Such attention has led to an increase in studies on the impacts of reservoir operation on river flow; however, a holistic understanding of the compounded effects of hydropower dams on different hydrological characteristics is lacking, especially for large river basins such as the Amazon where hydropower development is on the rise. Here, we mechanistically quantify the historical impacts of existing dams and the potential impacts of the collective operation of existing and planned dams on a basin-wide scale in the Amazon for the 1981-2019 period. We build on the recently developed high-resolution (3-arcmin; similar to 5 km) river-floodplain-reservoir model, the CaMa-Flood-Dam, which is enhanced to realistically simulate hydropower dam operation considering maximized power production. Flood simulations are further downscaled to 3 arc-seconds (similar to 90 m) resolution to investigate the impacts of dams on fine-scale flood dynamics across the basin. Results indicate that existing dams have substantially altered downstream river flow and flooding patterns across the Amazon River basin. Specifically, large dams in the Amazonian subbasins, including the Xingu, Madeira, and Tocantins, have altered downstream river flow amplitude by up to 3 orders of magnitude. Further, the collective operation of existing and planned dams could increasingly alter river flow patterns, causing similar to 10% decrease in flood duration in many parts of the Amazon mainstem. Our results provide quantitative evidence on the severity of the hydrologic impacts of large hydropower dams and have important implications for sustainable hydropower operation and development in the Amazon and worldwide.