水库拦截改变了河流天然径流和物质循环过程，水库碳通量及其生物地球化学循环过程复杂，是当前内陆水文和生态环境研究的前沿，水库碳通量同时也是关系到水电绿色能源属性和可持续发展的重大问题。 相关理论研究十分薄弱，相关机制的认知缺位，严重制约了对大型水电工程温室气体减排效益的科学评估。 三峡工程的水库碳通量问题直接关系到我国能源安全和水电可持续发展的国家战略，是长江大保护和推动长江经济带发展的重要工作内容。
Reservoir interception has altered the natural runoff and material cycle process of rivers. The reservoir carbon flux and its biogeochemical cycle process are complex, which are the frontiers of the current inland hydrology and ecological environment research. The reservoir carbon flux is also a major issue related to the green energy attribute of hydropower and sustainable development. The weak theoretical research and the lack of awareness of relevant mechanisms seriously restrict the scientific evaluation of greenhouse gas emission reduction benefits of large hydropower projects. The reservoir carbon flux of the Three Gorges Project is directly related to the national strategy of China ’ s energy security and sustainable development of hydropower, and it is an important work for the protection of the Yangtze River and the development of the Yangtze River Economic Belt.
项目开展了长期定位观测和关键过程研究，在深大水库碳通量及生物地球化学循环机制方面取得重要理论创新。
The project has carried out long-term observation of fixed station and key process research, and made important theoretical innovation in carbon flux and biogeochemical cycle mechanism of deep reservoirs.
（1）三峡水库重要水域碳通量及其环境影响因素定位观测。 研发了具有自主知识产权的水气界面碳通量动态连续观测技术及装备，突破了当前学术界的技术瓶颈，首次在三峡水库干流及支流开展连续性高精度分辨率的走航式温室气体在线观测，系统提高了三峡水库不同深度溶存温室气体的观测效率和精度，获取了长序列的科学观测数据，填补了亚热带地区水库碳通量数据空白，同时，掌握三峡水库水化学变化特征、水环境碳转化的热力学平衡关系，深刻认识三峡水库湖沼化过程中水环境热力学平衡关系。
(1) Observation in fixed location of carbon flux and its environmental impact factors in important water areas in the Three Gorges Reservoir. Having developed the technology and equipment for the dynamic and continuous observation of air-water interface carbon flux with independent intellectual property, which has broken through the technical bottleneck of the current academic circles; carried out for the first time the continuous and high-resolution underway online observation of greenhouse gas in the main stream and tributaries of the Three Gorges Reservoir, systematically improving the observation efficiency and accuracy of greenhouse gas dissolved in different depths of the Reservoir, obtaining the long-term observation data and filling the carbon flux data gap of reservoirs in subtropical regions; and mastered the hydrochemical change characteristics and the thermodynamic equilibrium relationship of carbon transformation in the water environment, reaching a further understanding of the thermodynamic equilibrium relationship of water environment of the Three Gorges Reservoir in its process of swampiness.
（2）三峡水库碳生物地球化学循环关键过程的理论研究。 综合交叉应用同位素示踪、分子生物学、环境微生物学的多学科现代技术，针对三峡水库关键界面与重要过程开展了机理研究，基于深大水库“点—线—面—体”立体角度认识水体温室气体的赋存状态及驱动过程，阐明三峡水库碳源汇通量动态及关键界面与过程的生物地球化学机制。
(2) Theoretical study on key processes of carbon biogeochemical cycle in the Three Gorges Reservoir. With the combined use of multidisciplinary modern technologies, including isotope tracing, molecular biology and environmental microbiology, this project has studied the mechanism of key interfaces and important processes of the Three Gorges Reservoir, understood the occurrence state and driving process of greenhouse gas in water body from the three-dimensional point-line-surface-body perspective of deep reservoir, and clarified the dynamics of carbon source flux and biogeochemical mechanism of key interfaces and processes in the Three Gorges Reservoir.
（3）三峡水库碳排放量核算校核及综合影响评估。 基于关键过程的定量解析，修订和纠正了三峡水库水-气碳交换通量的前期估算结果，提出了定量计算三峡水库不同调度模式下的碳排放通量的新方法，客观认识三峡水库产生的排放量水平，为科学评价三峡工程的绿色能源效益提供数据和理论基础。
(3) Carbon emissions accounting check and comprehensive impact assessment of the Three Gorges Reservoir. Having revised and corrected the preliminary estimation results of water-air carbon exchange flux of the Three Gorges Reservoir based on the quantitative analysis of key processes, put forward a new method to quantitatively calculate the carbon emission flux of the Reservoir in different operation modes, reaching an objective understanding of the emission level generated by the Reservoir, providing data and theoretical basis for the scientific evaluation of the green energy benefit of the Project.
图1 水化学分析及不同深度 pCO 2 分布特征
Fig. 1 Hydrochemical Analysis and pCO 2 Distribution Characteristics at Different Depths
图2 三峡水库水体溶解甲烷浓度分布图
Fig. 2 Distribution of Dissolved Methane Concentration in the Three Gorges Reservoir
Fig. 3 Distribution of Dissolved Methane and Carbon Dioxide Concentration in the Mainstream of the Three Gorges Reservoir
