Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu 610041, China.
Sci Total Environ. 2018 Jan 1;610-611:641-650. doi: 10.1016/j.scitotenv.2017.08.088. Epub 2017 Aug 17.
There is little available information on hydrochemistry of waters from glacial source to downstream of glacierized catchments. Here we examine the water chemistry of the snowpacks, lakes and streams at eight sampling sites within glacial basin in Mt. Dagu, east Tibetan Plateau. An air mass trajectory model, correlation analysis, Gibbs model, Piper diagram and hydrograph separation analysis were utilized to investigate the characteristics and solutes sources of these waters. Generally, the TDS (Total dissolved solids; 7.54, 13.95 and 18.70mg/L for snowpacks, lakes and streams respectively) and concentrations of main chemicals in all samples exhibited downstream trend from snowpacks to streams. Of the cations, Ca appeared with the highest concentration followed by K and Na. Of the anions, HCO was most abundant, followed by Cl, SO and NO. For snowpack samples, the air masses arriving at the sampling sites were typically prevailing from the western Tibet Plateau, central Asia and the northern Mongolia plateau. The fine particulate matter in the Mt. Dagu snowpacks was most likely transported long range from three arid regions above-mentioned. High concentrations of SO and NH in snowpacks, with twice as much NH as SO, implying that the soluble part of the finer particles was transported as a form of ammonium sulfate. Rock weathering determined the ion components of the meltwater and the water could be classified as calcium and bicarbonate type based on the Piper diagram. The chemical contributions from glacier-snow meltwater were 20%-131% for lake and 5%-79% for stream, while the runoff contribution to lake varied from 65.4% to 84.9%, and 66.1% to 81.6% for stream. This study suggested that glacier-snow meltwater was the mainly runoff contributor to lake and stream water and that snowpack solutes derived from eolian additions exert a significant influence on lake and stream chemistry.
关于冰川源至冰川流域下游水体的水化学性质，相关资料十分有限。本研究以青藏高原东部大巴山冰川流域内 8 个采样点的积雪、湖泊和溪流为研究对象，运用大气轨迹模式模型、相关分析、Gibbs 模型、Piper 图和水文学分离分析，探讨了这些水体的特征及其溶质来源。总的来说，TDS（总溶解固体）在积雪、湖泊和溪流中的浓度分别为 7.54、13.95 和 18.70mg/L，所有样本中的主要化学物质浓度均表现出从积雪到溪流的下游趋势。在阳离子中，Ca 的浓度最高，其次是 K 和 Na。在阴离子中，HCO 最丰富，其次是 Cl、SO 和 NO。对于积雪样本，到达采样点的气团通常主要来自青藏高原西部、中亚和蒙古高原北部。大巴山积雪中的细颗粒物很可能是从上述三个干旱地区长距离传输而来的。积雪中 SO 和 NH 的浓度较高，NH 的浓度是 SO 的两倍，这表明更细小颗粒的可溶性部分是以硫酸铵的形式输送的。岩石风化决定了融水的离子成分，根据 Piper 图，水可分为钙和碳酸氢盐型。湖泊中冰川融水的化学贡献为 20%-131%，溪流中为 5%-79%，而湖泊的径流量贡献为 65.4%-84.9%，溪流为 66.1%-81.6%。本研究表明，冰川融水是湖泊和溪流的主要径流来源，而积雪中的溶质主要来源于风成物质的添加，对湖泊和溪流的化学性质有重要影响。
