Li Xuan, Yuan Xin, Men Cong, Yang Jing-Yi, Zuo Jian-E
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Huan Jing Ke Xue. 2024 Aug 8;45(8):4932-4945. doi: 10.13227/j.hjkx.202308056.
Methane （CH） and nitrous oxide （NO） are concerning greenhouse gases. Urban rivers have been important emission sources of CH and NO in recent years. It is meaningful for city greenhouse gas reduction to provide a systematic analysis of spatiotemporal characteristics, mechanisms, and influencing factors of the production and emission of CH and NO from urban rivers. This study combed measured data of urban river CH and NO dissolution concentrations and emission fluxes from related literature published in the past 20 years and also concluded the spatiotemporal characteristics of urban river CH and NO emissions. This study estimated that CH and NO emissions （expressed by CO-eq） from urban rivers in Beijing were 234.63 and 59.53 Gg CO-eq in 2018, whereas CH and NO emissions （expressed by CO-eq） from urban rivers in Shanghai were 159.86 and 260.24 Gg CO-eq in 2018, respectively. These results demonstrated that urban rivers have become important CH and NO emission sources. This study summarized the production/consumption processes and import/export pathways of CH and NO in urban rivers. What is more, this study discussed the main influencing factors of urban river CH and NO production and emissions from the perspectives of river environmental conditions and urbanization effects. At last, the present work prospected the future research trends of urban river CH and NO emissions and provides urban rivers with scientific support for greenhouse gas reduction.
甲烷（CH₄）和一氧化二氮（N₂O）是令人关注的温室气体。近年来，城市河流已成为CH₄和N₂O的重要排放源。系统分析城市河流CH₄和N₂O产生与排放的时空特征、机制及影响因素，对于城市温室气体减排具有重要意义。本研究梳理了过去20年发表的相关文献中城市河流CH₄和N₂O溶解浓度及排放通量的实测数据，总结了城市河流CH₄和N₂O排放的时空特征。本研究估计，2018年北京城市河流的CH₄和N₂O排放量（以CO₂当量表示）分别为234.63 Gg CO₂当量和59.53 Gg CO₂当量，而2018年上海城市河流的CH₄和N₂O排放量（以CO₂当量表示）分别为159.86 Gg CO₂当量和260.24 Gg CO₂当量。这些结果表明，城市河流已成为重要的CH₄和N₂O排放源。本研究总结了城市河流中CH₄和N₂O的产生/消耗过程及输入/输出途径。此外，本研究从河流环境条件和城市化效应的角度讨论了城市河流CH₄和N₂O产生与排放的主要影响因素。最后，本研究展望了城市河流CH₄和N₂O排放的未来研究趋势，为城市河流温室气体减排提供科学支持。
