Journal of Geographical Sciences ›› 2010, Vol. 20 ›› Issue (1): 109-120.doi: 10.1007/s11442-010-0109-x

• Environmental Chemistry • Previous Articles     Next Articles

Composition, spatial distribution, and environmental significance of water ions in Pumayum Co catchment, southern Tibet

ZHU Liping1, JU Jianting1,2, WANG Yong1,3, XIE Manping1,3, WANG Junbo1, PENG Ping1,3, ZHEN Xiaolin1,3, LIN Xiao1,3   

  1. 1. Institute of Tibetan Plateau Research, CAS, Beijing 100085, China;
    2. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    3. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2009-04-23 Revised:2009-07-06 Online:2010-02-15 Published:2010-02-15
  • Contact: Ju Jianting (1977–), Ph.D, specialized in lake sediment and environmental change. E-mail:zhulp@igsnrr.ac.cn
  • About author:Zhu Liping (1965–), Professor, specialized in ostracod and paleo-environmental studies. E-mail: zhulp@igsnrr.ac.cn
  • Supported by:

    National Natural Science Foundation of China, No.40871099; National Basic Research Program of China, No.2005CB422002; Knowledge Innovation Project of CAS, No. KZCX2-YW-146-4

Abstract:

The chemistry of major cations (Mg2+, Ca2+, Na+, and K+) and anions (HCO3 ?, SO4 2?, and Cl?) in the water of Lake Pumayum Co and its inflow river was studied, revealing the obvious ionic difference among various inflow rivers and the lake. The chemical type of the lake water was Mg2+-Ca2+-HCO3 ?-SO4 2+, but the major ions of the main inflow rivers were Ca2+-Mg2+-HCO3 ?. In the lake inlet of Jiaqu River, the main inflow river, there was significant variance of water chemistry within the depth less than 2 m. However, it was almost homogeneous at other area of the lake. Therefore, with the evidence of distribution of water chemistry and oxygen isotope of lake water, a conclusion can be outlined that Jiaqu River had a distinct effect on the hydrochemistry of the water on the submerged delta, whereas this is not the case for other rivers. The Gibbs plot revealed that the dominant mechanism responsible for controlling chemical compositions of the lake water was rocks weathering in the drainage area. Ion ratios and ternary plots further explored the main processes controlling the water chemistry of the catchment, i.e., carbonate weathering, pyrite weathering, and silicate weathering. The different hydrochemistry characteristics between river water and lake water may result from the CaCO3 precipitation. The findings will benefit the explanation of the environmental significance of carbonate in paleolimnological studies in the lake.

Key words: Lake Pumayum Co, hydrochemistry, spatial distribution, sedimentary process, carbonate