, Bӧckingstr. 55, Kӧln Mülheim 51063, Cologne, Germany.
Department of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, UK.
Environ Sci Pollut Res Int. 2021 Feb;28(7):8936-8944. doi: 10.1007/s11356-020-11746-4. Epub 2021 Jan 6.
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, 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.
在全球对水、能源和粮食的需求迅速增长的情况下，修建大型水坝预计仍将继续。由于尼罗河东部流域人民面临着巨大的机遇和风险，尼罗河上的埃塞俄比亚复兴大坝（GERD）引起了地区和国际的关注。一旦建成，它将成为非洲最大的水电站，也是世界上最大的水电站之一。自 2011 年大坝开始建设以来，来自埃塞俄比亚、苏丹和埃及的科学家和谈判代表一直在就大坝的设计、初期蓄水和长期运行进行讨论，但尚未达成协议。迄今为止，讨论主要集中在对水电生产、水资源供应和灌溉农业的影响上，而对大坝的潜在环境影响关注甚少。在这里，我们根据其他大坝的知识和 GERD 的一些特点，就这一差距表达我们的观点。由于水温、盐度和含氧量可能发生变化，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。GERD 预计的淹没面积、在热带低纬度的位置和深涡轮进水口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。如果与清洁的间歇性太阳能和风能相结合，大坝的电力也可以减少区域温室气体排放。最大水库面积为 1904 平方公里，水面蒸发，进而当地极端降水和湿度可能会增加。上述影响可能会对跨界生态、农业和健康产生影响，因此，应与大坝的效益一并考虑。
