| 三峡库区溶解性有机质空间分布特征及来源解析 |
| 摘要点击 830 全文点击 101 投稿时间：2024-04-19 修订日期：2024-06-19 |
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| 中文关键词 三峡库区 溶解性有机质（DOM） 空间变化 三维荧光光谱（3D-EEMs） 平行因子分析（PARAFAC） |
| 英文关键词 Three Gorges Reservoir Area dissolved organic matter （DOM） spatial variations three-dimensional fluorescence spectroscopy （3D-EEMs） parallel factor analysis （PARAFAC） |
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| 中文摘要 |
| 内陆水体溶解性有机质（DOM）在区域及全球碳循环中扮演着重要角色. 然而,对于重要水利工程影响区域河流DOM光谱特征及溯源分析的综合研究尚不充分. 基于此,以三峡库区干流与典型支流为研究对象,采用紫外-可见吸收光谱（UV-Vis）和三维荧光光谱（3D-EEMs）,结合平行因子分析（PARAFAC）,对库区内干流与典型支流DOM的光谱特性及空间分布规律进行系统研究. 结果表明,三峡库区河流DOM为内源和陆源共同驱动,以内源贡献为主,总体呈弱腐殖化特征,自生源信号较强. 其中干流DOM相对分子质量更大,碳骨架聚合程度更高且结构更为复杂. 三峡库区干流和典型支流FI值范围分别为1.79~2.48和1.62~2.03,均值分别为1.95和1.93；干、支流BIX均值分别0.92和0.85. FI和BIX结果表明库区河流DOM为内源和陆源共同驱动,且以内源为主. EEMs-PARAFAC分析表明除了相似的C1（腐殖质）和C2（酪氨酸）组分,干流DOM还包括混合类腐殖质组分C3. 相关性分析显示,由于人为干扰、土地利用和支流累积等影响,三峡库区干流与典型支流DOM的光谱特性具有明显的空间异质性和关联性. 以上结果为三峡库区河流水生态系统的保护与管理提供了科学参考. |
| 英文摘要 |
| Dissolved organic matter （DOM） in inland waters plays an important role in the regional and global carbon cycles. However, limited comprehensive studies are available on the spectral characterization and traceability analysis of DOM in river systems affected by crucial hydraulic projects. This study focuses on the main stream and typical tributaries within the Three Gorges Reservoir Area. Ultraviolet-visible absorption spectroscopy （UV-vis） and three-dimensional fluorescence spectroscopy （3D-EEMs）, combined with parallel factor analysis （PARAFAC）, were used to systematically investigate the spectral properties and spatial distribution patterns of DOM in the reservoir area. The findings demonstrated that the riverine DOM in the Three Gorges Reservoir Area was influenced by a combination of endogenous and terrestrial sources, where endogenous contributions were predominant. Moreover, the riverine DOM displayed a weak humification characteristic and strong autochthonous signal. Notably, DOM in the main stream exhibited a higher relative molecular weight, greater degree of carbon skeleton polymerization, and more complex structure. The FI values of the main stream and typical tributaries in the Three Gorges Reservoir Area ranged from 1.79 to 2.48 and 1.62 to 2.03, with mean values of 1.95 and 1.93, respectively. Additionally, the mean values of BIX in the main stream and tributaries were 0.92 and 0.85, respectively. The results of the FI and BIX analyses indicated that the riverine DOM of the reservoir area was driven by both endogenous and terrestrial sources, with the prevalence of endogenous sources. EEMs-PARAFAC analysis revealed that, in addition to the analogous C1 （humic-like） and C2 （tyrosine-like） fractions, DOM in the main stream also included a mixed humic-like fraction, C3. Correlation analysis revealed that the spectral characteristics of DOM in the main stream and representative tributaries in the Three Gorges Reservoir Area exhibited pronounced spatial heterogeneity and correlation because of the effects of anthropogenic disturbances, land use, and cumulative effects of the tributaries. These findings provide scientific insights for the conservation and management of aquatic ecosystems in the Three Gorges Reservoir Area. |
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