Earth Science Frontiers ›› 2008, Vol. 15 ›› Issue (5): 194-202.

• Article • Previous Articles     Next Articles

Major ion chemistry in the Yangtze River.

  

  1. 1School of Earth Science and Resources, China University of Geosciences (Beijing), Beijing 100083, China
    2National Research Center of Geoanalysis, Beijing 100037, China
    3Department of Earth Sciences, Nanjing University, Nanjing 210093, China
    4College of Environmental Science and Engineering, Hohai University, Nanjing 210098, China

  • Online:2008-05-02 Published:2008-05-02

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Abstract:

 36 water samples were collected in the main Yangtze River channel and 40 in its tributaries. Concentrations of Ca2+,Mg2+,Na+,K+,HCO-3,SO2-4,Cl-and SiO2 in the water samples were determined. It was found that the chemistry of the Yangtze River is dominated by the weathering of carbonates and evaporites with high K+, Na+, Cl- and SO2-4 concentrations in the upstream of the Yangtze River, i.e. Tuotuohe, Tongtianhe and Jinshajiang, and Ca2+ and HCO-3 dominating the cations and anions in the middle and lower stream of the Yangtze River; All the major ions in Yangtze River water, especially Na+,K+,SO2-4 and Cl-, have increased significantly compared with data acquired from 1950s to 1990; Dongting Lake and Poyang Lake are the first two ion sources of the main Yangtze River channel. Besides the two lakes, the Minjiang River is the first source for Na+, K+, Ca2+, Mg2+, F- and HCO-3, and the Jialing River is the first source for SO2-4 and dissolved SiO2; the Yangtze River is the biggest source of Mg2+, SO2-4 and Cl- for the ocean, and its fluxes for Ca2+ and HCO-3 is next to the Amazon River.

Key words:

Key words: Yangtze River; geochemistry; major ion chemistry; weathering; flux

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