Title: Distribution of major ions in waters and their response to regional climatic change in Tibetan lakes
Abstract: 于20092010年对西藏34个湖泊表层水体进行采样和水质参数测量,测试不同湖泊水体主要离子浓度,分析其分布特征和对区域气候变化的响应. 研究表明,不同湖泊水体的主要离子浓度及其水质参数存在差异,西藏大部分湖泊离子浓度高于全国甚至全球湖泊平均水平. 湖泊的水化学类型主要为氯化物型,少部分是硫酸盐型. 西藏湖泊受强烈蒸发作用的影响,水化学类型从东南到西北依次为碳酸盐型-硫酸钠型-硫酸钾型-氯化物型. 对比1990s前的研究发现,大部分湖泊水体的主要离子浓度较上世纪有所降低,且部分湖泊水化学类型也发生了变化,该变化反映了过去几十年来西藏湖泊水化学对区域气候变化的响应.;During 2009-2010, surface water samples from 34 Tibetan lakes were collected and measured for major ions. The distribution pattern of ionic concentrations and its response to regional climatic change were investigated. Results revealed a large range of major ionic concentrations as well as other water parameters for the lakes. Most lakes showed higher ionic concentrations than lakes in other regions of China and even the world. Most of the lakes' water types were found to be Na(K)-Cl with a few as Ca(Mg)-SO<sub>4</sub>. Due to the effect of evapoconcentration, water types of Tibetan lakes showed a gradient variation in the order of Ca(Na)-HCO<sub>3</sub>Na(K)-SO<sub>4</sub>Na(K)-Cl along the southeast-northwest transect. Compared with the pre-1990s data, the concentrations of major ions in the majority of the lakes decreased and the water type of several lakes also changed. The variation of major ions and water types of Tibetan lakes indicated an obvious response in lake water chemistry to the regional climatic changes over decades.