ZhariNamco位于西藏西北部的高寒草原带,生态环境脆弱。作为西藏第三大湖泊,长期以来,缺乏有关其流域水环境的研究数据。为了阐明流域地表水环境特征及其影响因素,2021年8月至2022年6月进行了广泛的调查,包括高流量时期,低流量,和基础流。Further,该研究还涉及通过使用数理统计对流域湖泊采样点的水化学特征和时空变化进行综合评估,水化学分析,相关分析,和主成分分析。研究结果表明:①扎里纳姆科盆地的水呈碱性,湖中的主要离子成分包含Na+,SO42-,和Cl-,而河流的主要特征是Ca2+,HCO3-,和SO42-。②超过既定标准的主要污染物包括硫酸盐,砷,氯化物,和总磷。该研究确定了水质的显着时空变化。暂时,硫酸盐的过量,砷,总磷在高流量时期最为明显,其次是在低流量和基本流量期间,氯化物水平显示出较小的时间变化。空间上,河流水质超过湖泊,砷,总磷,TDS,硫酸盐,氯化物,K+,湖泊中的Na浓度比河流中的Na浓度高1至2个数量级。超过既定标准的水质主要是在湖中发现的,湖泊内部的空间变化较小。③发现流域内的水化学过程主要受自然现象的影响,包括蒸发浓缩和岩石风化。各种元素通过地表径流进入湖泊,它们在蒸发浓缩过程的影响下不断积累,最终导致超越。④水质的时间变化主要归因于高流量时期元素损失增加和蒸发加剧。水质的空间差异主要是由于流动水体和封闭水体之间的水动力条件不同。
Zhari Namco is situated in the alpine grassland belt of northwestern Xizang with a fragile ecological environment. As the third-largest lake in Xizang, there has been a long-term lack of research data concerning its basin water environment. In an effort to elucidate the surface water environment characteristics of the basin and the factors influencing them, an extensive investigation was conducted from August 2021 to June 2022, encompassing periods of high flow, low flow, and base flow. Further, the study also involved comprehensive assessments of the water chemistry characteristics and spatial-temporal variation in lake sampling sites of the basin that were not significant by using mathematical statistics, hydrochemical analysis, correlation analysis, and principal component analysis. The findings revealed the following: ① The water in the Zhari Namco Basin exhibited an alkaline nature, with dominant ionic compositions in the lake comprising Na+, SO42-, and Cl-, whereas the rivers were primarily characterized by Ca2+, HCO3-, and SO42-. ② The main pollutants exceeding established standards included sulfates, arsenic, chlorides, and total phosphorus. The study identified significant spatiotemporal variations in water quality. Temporally, the exceedance of sulfates, arsenic, and total phosphorus was most pronounced during high-flow periods, followed by that during low-flow and base flow periods, with chloride levels showing less temporal variation. Spatially, river water quality surpassed that of the lakes, with arsenic, total phosphorus, TDS, sulfate, chloride, K+, and Na+ concentrations in lakes 1 to 2 orders of magnitude higher than those in rivers. Water qualities exceeding the established standard were primarily found in the lake, with less spatial variations within the lake itself. ③ Hydrochemical processes within the basin were found to be primarily influenced by natural phenomena, including evaporation-concentration and rock weathering. Various elements entered the lakes via surface runoff, where they continuously accumulated under the influence of evaporation-concentration processes, ultimately leading to exceedances. ④ Temporal variations in water quality were primarily attributed to increased elemental loss and intensified evaporation during high-flow periods. The spatial discrepancies in water quality were predominantly a consequence of the differing hydrodynamic conditions between flowing water bodies and enclosed water bodies.