Atmospheric CO2 uptake by the chemical weathering of river basins was reviewed based on pioneering works.The chemical weathering of continents is the key linkage connecting the major carbon pools in the Earth. The chemical weathering of rocks, especially of silicate rocks, constitmes a major carbon sink in tbe global biogechemical cycles on a geological rime scale ,which is an important surficial geological proess that regulates the Earth's climate and makes the global changes relalively smooth. Rivers play a crucial role in the transferring of terrestrial material to the ocean, and the river system also records the signatures of various natural processes and human activities within the drainage basins. The contributions from chemical weathering of various rocks to the chemical runoff can be estimated and traced by surveying the chemical composition of river water and application of Gibbs diagram,mass balance method and isotopic tracer techniques. The rate of chemical weathering of rocks and consumption fluxes of atmospheric/soil CO2 can be calculated according to the chemical composition of river water within the drainage basins. Environmental factors affecting the rate of chemical weathering are different in different areas,which causes a significant difference in spatial distribution of geological carbon sequestration. The geological carbon sequestration potential of chemical weathering of rocks in humid tropieal and subtropical areas is about the mean annual fixing of 55kg CO2 per capita of China, which offsets partiaaly the earbon emissions in China.%通过对已有工作较为全面的分析,综述了流域化学风化过程对大气CO<,2>的吸收能力.陆地岩石的化学风化过程是联接地球各大碳库的关键环节.在地质时间尺度上陆地岩石的化学风化,尤其是硅酸盐岩的化学风化构成全球生物地球化学循环的重要碳汇,是调节地球气候性质使之相对稳定的关键表生地质过程.河流在陆地向海洋的物质输送中担任着重要角色,并且记录了流域内发生的各种自然过程和人类活动的信息.通过观测河流输送物质的化学组成,运用Gibbs图解法、质量平衡法和同位素示踪技术可以研究流域内各种岩石化学风化对化学径流组成的贡献,并据此计算出流域岩石化学风化的速率及其对大气CO<,2>的消耗通量.影响地表化学风化速率的环境因子存在地域差异,进而导致地质碳汇的空间分布也存在较大差别.北半球湿热季风地区的地质碳汇在全球碳的生物地球化学循环中具有重要意义.我国湿热地区化学风化过程的地质碳汇能力相当于13亿人口人均固定CO<,2>量大约为55kg/a,可抵消我国部分碳排放量.
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