Wang Xiaodan, Li Shijie, Liu Cong-Qiang, Mostofa Khan M G, Zhao Zhiqi, Luo Rongqin
a State Key Laboratory of Environmental Geochemistry , Institute of Geochemistry, Chinese Academy of Sciences , Guiyang , Guizhou , China.
b University of Chinese Academy of Sciences , Beijing , China.
Isotopes Environ Health Stud. 2018 Mar;54(1):89-105. doi: 10.1080/10256016.2017.1343825. Epub 2017 Jun 30.
This study established the hydrochemistry and stable isotope variations in three lakes, namely brackish Zigetang Co, freshwater Cona and Ranwu lakes located in the central and southeastern Tibetan Plateau of China. Vertical profile fluctuations in the water column, such as temperature and dissolved oxygen (DO) concentration, displayed significant differences which were linked to the thermocline. The hydrochemistry of the three lakes showed that [Formula: see text] as the dominant anion, whereas Na is the main cation in Zigetang Co and Cona lake and Ca is the prevailing cation in Ranwu lake. In Zigetang Co, K and Na concentrations decreased by 42 % from 1999 to 2012, caused by the enlargement of the lake area, documented by field investigations carried out in 1998, 2002, 2006 and 2012. The δC and δO values analysed from the three lakes varied from -6.0 to 2.0 ‰, and from -14.8 to -6.4 ‰, respectively. The closed Zigetang lake showed higher δC and δO values compared to those of the rivers, the semi-closed Cona and open Ranwu lakes. The δC values of lake water in Zigetang Co were mainly controlled by CO exchange between lake water and atmosphere; the δO values were dominated by the evaporation/freshwater input ratios.
本研究确定了中国青藏高原中部和东南部的三个湖泊（微咸水的兹格塘错、淡水的错那湖和然乌湖）的水化学特征及稳定同位素变化。水柱中的垂直剖面波动，如温度和溶解氧（DO）浓度，显示出与温跃层相关的显著差异。这三个湖泊的水化学特征表明，[公式：见原文]为主要阴离子，而在兹格塘错和错那湖中，Na是主要阳离子，在然乌湖中，Ca是占主导地位的阳离子。在兹格塘错，1999年至2012年期间，K和Na浓度下降了42%，这是由于湖泊面积扩大导致的，1998年、2002年、2006年和2012年进行的实地调查记录了这一情况。从这三个湖泊分析得到的δC和δO值分别在-6.0至2.0‰和-14.8至-6.4‰之间变化。与河流、半封闭的错那湖和开放的然乌湖相比，封闭的兹格塘湖显示出更高的δC和δO值。兹格塘错湖水的δC值主要受湖水与大气之间的CO交换控制；δO值则主要受蒸发/淡水输入比的影响。
