青藏高原化学风化和对大气CO_2的消耗通量  

Chemical Weathering and Atmospheric CO_2 Consumption of Qinghai—Xizang(Tibet) Plateau

作　　者：吴卫华[1] 杨杰东[2] 徐士进[1] 

机构地区：[1]南京大学地球科学系,南京210093 [2]南京大学现代分析中心,南京210093

出　　处：《地质论评》2007年第4期515-528,共14页Geological Review

基　　金：国家自然科学基金资助项目(编号40473009和40331001)的成果

摘　　要：为了评估青藏高原化学风化对全球气候的影响,笔者等对中国境内源自青藏高原的七条主要河流(金沙江、澜沧江、怒江、黄河、雅砻江、岷江和大渡河)进行了采样和地球化学分析,估算了硅酸盐、碳酸盐风化对河水中主量离子的贡献,以及硅酸盐风化和碳酸盐风化所消耗的大气CO2。研究显示,七条河流流域中硅酸盐风化引起的大气CO2消耗约为0.7×105～3.7×105mol/(km2.a)。结合国外学者对于喜马拉雅山南缘三条河流(恒河、布拉马普特拉河和印度河)的研究结果可以得出,发源于喜马拉雅山—青藏高原的主要十条河流流域硅酸盐风化平均共消耗大气CO2328×109mol/a,仅占全球大陆硅酸盐岩风化所消耗大气CO28700×109mol/a的3.8%,并仅为全球通过河流向海洋输送有机碳(来自陆地上生物的消耗)通量的2.5%。In order to evaluate better the influence of weathering of the Qinghai-Xizang（Tibet） Plateau and the Himalaya on the global climate, we present river chemistry data for the seven Chinese rivers（the Jinsha River, Yalong River, Minjiang River, Dadu River, Lancang River, Nujiang River and Yellow River） originating in the Qinghai-Xizang（Tibet） Plateau, examine detailedly the geochemistry of these rivers and estimate contributions from silicate and carbonate weathering on the major ions in these river water, we also present CO2 consumption fluxes via silicate and carbonate weathering. The results show that in tlaese rivers, the long term COz consumption by silicate weathering in the seven Chinese river basins range from 0. 7 × 10^5 mol/（km^2 · a） to 3.7 × 10^5 mol/（km^2 · a）. Combined with the Ganges, Brahmaputra and Indus, the main ten rivers originating in the Himalaya and Qinghai--Xizang（Tibet） Plateau consume the atmospheric CO2 328 × 10^9 mol/a in all. But it is only 3.8% of the CO2 consumption derived by the global silicate weathering （8700 × 10^9 mol/a）, and only accounting for 2. 5% of the flux of organic carbon transported annually to the ocean by rivers.

关 键 词：青藏高原-喜马拉雅山 河流 大陆风化 CO2消耗通量 

分 类 号：P594.2[天文地球—地球化学]