乌伦古湖冰封期溶解性有机质分布特征及来源解析

乌伦古湖作为新疆第二大湖泊，对维护西北地区生态平衡具有重要意义。为探究乌伦古湖在冰封期有机指标超标原因，以冰封期水体溶解性有机质（DOM）为研究对象，运用紫外-可见光吸收光谱与三维荧光光谱结合平行因子模型（PARAFAC）、相关性分析等手段，对乌伦古湖DOM进行空间分布特征以及来源解析的探讨。结果显示：1）冰封期乌伦古湖水体DOM紫外-可见吸收光谱参数（E₃/E₄）大于3.5，表明水体腐殖质以富里酸为主，PARAFAC分析得出乌伦古湖水体DOM包含3种主要荧光组分，即陆源腐殖质（C1，39.03%）、类色氨酸物质（C2，38.20%）和富里酸物质（C3，22.77%）。2）乌伦古湖水体荧光指数（FI）平均值为1.64、腐殖化指数（HIX）为1.66、自生源指数（BIX）为1.03，荧光特征参数表明水体DOM由陆源及自生源共同组成，且具有腐殖化程度较低、新近自生源高的特征，表明乌伦古湖水体DOM以内源产生为主。3）乌伦古湖水体腐殖质（C1、C3）与类蛋白组分（C2）显著相关（P<0.01），表明腐殖质与类蛋白组分的产生及来源具有一致性。

Dissolved organic matter distribution characteristics and source analysis of Ulungur Lake during ice sealing period

As the second largest lake in Xinjiang, Ulungur Lake is of great significance in maintaining the ecological balance in the northwest region of China. In order to explore the reasons why the organic indexes of Ulungur Lake exceeded the standard during the ice sealing periods, the dissolved organic matter (DOM) of water body during the ice sealing period was taken as the research object, and the spatial distribution characteristics and source analysis of DOM in Ulungur Lake were discussed by means of ultraviolet-visible absorption spectroscopy and three-dimensional fluorescence spectroscopy combined with parallel factor model (PARAFAC) and correlation analysis. The results showed that the ultraviolet-visible absorption spectrum parameters (E3/E4) of DOM in Ulungur Lake during the ice-sealing period were greater than 3.5, indicating that the water humus was mainly fulvic acid. PARAFAC analysis showed that DOM of Ulungur Lake contained three main fluorescent components, namely terrestrial humus (C1, 39.03%), tryptophan-like substance (C2, 38.20%) and fulvic acid substance (C3, 22.77%). The average fluorescence index (FI), humification index (HIX ) and autochthonous index (BIX) of the water body of Ulungur Lake were 1.64, 1.66 and 1.03, respectively. The fluorescence characteristic parameters showed that the DOM of the water body was composed of terrestrial and autochthonous sources, and had the characteristics of low humification and high autochthonous sources, indicating that the DOM of the water body of Ulungur Lake was mainly produced by endogenous sources. Humus (C1, C3) was significantly correlated with protein-like components (C2) (P< 0.01), indicating that the production and source of humus and protein-like components were consistent. The study on the characteristics of DOM in Ulungur Lake during the ice sealing period could provide a theoretical basis for the treatment of organic pollution in Ulungur Lake.