Would Africa's largest hydropower dam have profound environmental impacts?
Would Africa's largest hydropower dam have profound environmental impacts?
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DOI：
10.1007/s11356-020-11746-4
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发表时间：
2021-01-06
影响因子：
5.8
通讯作者：
Basheer, Mohammed
中科院分区：
文献类型：
--
作者：
Elagib, Nadir Ahmed;Basheer, Mohammed
面对全球对水、能源和粮食需求的快速增长，预计建造大型水坝的工作将继续下去。由于对东尼罗河流域人民的潜在机会和风险，尼罗河上的埃塞俄比亚复兴大坝（GERD）引起了区域和国际的关注。一旦建成，它将成为非洲最大的水电大坝，也是世界上最大的水电大坝之一。自2011年开工以来，来自埃塞俄比亚、苏丹和埃及的科学家和谈判代表就GERD的设计、初始填充和长期运营进行了讨论，但尚未达成协议。迄今为止，讨论的重点是对水电生产，水的可用性和灌溉农业的影响，很少注意到大坝的潜在环境影响。在这里，我们交流我们对这一差距的看法，借鉴世界各地其他大坝的知识和一些GERD的特点。与GERD相关的水文变化可能会对下游的鱼类、水生植物和生物多样性产生不利影响，因为水温、盐度和氧含量可能会发生变化。GERD的预计淹没区，在热带低纬度的位置，以及深涡轮机的摄入量可能会加剧温室气体排放，而大坝的高水库深度将减少排放。如果与更清洁的间歇性太阳能和风能相结合，大坝的电力还可以减少区域温室气体排放。最大水库面积为1904 km（2），地表蒸发量可能会增加，从而导致当地极端降水和湿度增加。上述影响可能具有跨界生态、农业和健康影响，因此，应与大坝的好处一起考虑。
In the face of rapid growth in the global demands for water, energy, and food, building large dams is expected to continue. Due to its potential opportunities and risks for the people of the Eastern Nile Basin, the Grand Ethiopian Renaissance Dam (GERD) on the Nile River has commanded regional and international attention. Once completed, it will rank the largest hydropower dam in Africa and among the largest worldwide. Discourse among scientists and negotiators from Ethiopia, Sudan, and Egypt on the design, initial filling, and long-term operation of the GERD is ongoing since the construction started in 2011, but no agreement has yet been reached. The discourse has hitherto focused on the impacts on hydropower production, water availability, and irrigated agriculture, with little attention to the dam's potential environmental impacts. Here, we communicate our viewpoint on this gap, drawing on knowledge from other dams around the world and some GERD characteristics. The hydrological alterations associated with the GERD could adversely impact fish, aquatic plants, and biodiversity in the downstream due to possible changes in water temperature, salinity, and oxygen content. The GERD's expected flooded area, location at low latitude in the tropics, and the deep turbine intakes could intensify greenhouse gas emissions, whereas the dam's high reservoir depth would abate the emissions. The dam's electricity could also reduce regional greenhouse gas emissions if combined with cleaner intermittent solar and wind energy sources. With a maximum reservoir area of 1904 km(2), surface evaporation and consequently local extreme precipitation and humidity could increase. The aforementioned impacts could have transboundary ecological, agricultural, and health implications and, therefore, should be taken into consideration alongside the benefits of the dam.