|ZHANG Fei,JIN Zhang-dong,SHI Yue-wei,QIU Xin-ning,QI Ru-gui.2013.Seasonal and spatial variations of water chemistry in Lake Qinghai and its influence by authigenic carbonate precipitation[J].Journal of Earth Environment,(3):1314-1321
|关键词: 青海湖 季节变化 空间变化 水化学 沉积物捕获器
|Seasonal and spatial variations of water chemistry in Lake Qinghai and its influence by authigenic carbonate precipitation
ZHANG Fei1, JIN Zhang-dong1, SHI Yue-wei2, QIU Xin-ning2, QI Ru-gui2
1.State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi′an 710075, China; 2.The Bureau of Hydrology and Water Resources of Qinghai Province, Xining 810001, China
|Seasonal and spatial variation characteristics of lake water within the Lake Qinghai catchment are of significance for understanding precipitation process and environmental significance of authigenic carbonates and the lake′s evolution trend. In this study, seasonal lake waters were collected once a month over a whole year period by a sediment trap in Lake Qinghai, and spatial samples were collected in Lake Qinghai and its satellite lakes. The analyses for seasonal samples showed that the cations reached the highest values during the dry season (December to next April), and decreased during the rainy season. Ca- and/or Mg-carbonate precipitation started from February to March, and such precipitation process would reach maximum during the rainy season, resulting in stable concentrations of Ca2+ and Mg2+. During the late rainy season, partial dissolution of Mg containing carbonates might also happened. The analyses for spatial water samples showed that Ca2+ and Sr2+ concentrations of lake water would be basically stable owing to precipitation of authigenic carbonates, whereas Mg2+, Na+, and K+ would continue to accumulate in the future evolution processes of Lake Qinghai. Its water chemistry will change towards that of Haiyan-wan Lake and further towards that of Gahai Lake. This study further reveals the potential response of authigenic carbonate precipitation to climate change over a longer time scale.
|Key words: Lake Qinghai seasonal variation spatial variation water chemistry sediment trap