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Abstract 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; ∼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 (∼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 ∼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.
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Why we should not build large hydropower dams in the Amazon (or anywhere else)
Large hydropower dams and plants have been an engineering feat and a source of national pride in both the Global North and South. They were promoted as a source of clean energy almost unquestionably until the environmental awakening of the 60’s. Since then, the growing number of documented socioenvironmental impacts caused by large dams have put this energy source under scrutiny. Nevertheless, dam builders continue to promote this solution based on outdated arguments and unfulfilled promises connected to the creation of jobs, stimulation of the regional economy by the production of vast amounts of cheap electricity, improvement of local water quality and infrastructure, amongst others. Considering that most of the large dams currently planned or under construction are situated in socioenvironmentally sensitive areas, such as the Amazon, which conservation is of high importance for reaching of climate goals, this paper deconstructs myths created by dam boosters in order to reach the conclusion that large dams should not be built in the Amazon (or anywhere else).
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- Award ID(s):
- 2020790
- PAR ID:
- 10543557
- Editor(s):
- Fuchs, Vanessa Boanda
- Publisher / Repository:
- La Revista
- Date Published:
- Edition / Version:
- 82
- Page Range / eLocation ID:
- 64-73
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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