Ni Jinren, Wang Haizhen, Ma Tao, Huang Rong, Ciais Philippe, Li Zhe, Yue Yao, Chen Jinfeng, Li Bin, Wang Yuchun, Zheng Maosheng, Wang Ting, Borthwick Alistair G L
Key Laboratory for Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
Laboratoire des Sciences du Climat et de l'Environnement, Institut Pierre Simon Laplace, Commissariat à l'Énergie Atomique et aux Ènergies Alternatives, CNRS, Université de Versailles Saint-Quentin-en-Yvelines, Gif-sur-Yvette 91191, France.
Natl Sci Rev. 2022 Jan 28;9(6):nwac013. doi: 10.1093/nsr/nwac013. eCollection 2022 Jun.
Dams are often regarded as greenhouse gas (GHG) emitters. However, our study indicated that the world's largest dam, the Three Gorges Dam (TGD), has caused significant drops in annual average emissions of CO, CH and NO over 4300 km along the Yangtze River, accompanied by remarkable reductions in the annual export of CO (79%), CH (50%) and NO (9%) to the sea. Since the commencement of its operation in 2003, the TGD has altered the carbonate equilibrium in the reservoir area, enhanced methanogenesis in the upstream, and restrained methanogenesis and denitrification via modifying anoxic habitats through long-distance scouring in the downstream. These findings suggest that 'large-dam effects' are far beyond our previous understanding spatiotemporally, which highlights the fundamental importance of whole-system budgeting of GHGs under the profound impacts of huge dams.
大坝通常被视为温室气体排放源。然而,我们的研究表明,世界上最大的大坝——三峡大坝,已使长江沿线4300多公里的一氧化碳、甲烷和一氧化氮年平均排放量显著下降,同时向海洋的一氧化碳年输出量(79%)、甲烷(50%)和一氧化氮(9%)也大幅减少。自2003年运行以来,三峡大坝改变了库区的碳酸盐平衡,增强了上游的甲烷生成,并通过下游的长距离冲刷改变缺氧生境,抑制了甲烷生成和反硝化作用。这些发现表明,“大坝效应”在时空上远远超出了我们之前的理解,这凸显了在大型大坝的深远影响下进行温室气体全系统预算的根本重要性。