| 摘要: |
| 2021年11月至2022年10月，每月于珠江下游广州段采集河水样品，并分析其中溶解有机碳(DOC)、发色溶解有机物(CDOM)和荧光溶解有机物(FDOM)的浓度和组成。采样期间，2022年6月珠江流域遭遇百年一遇的洪水。结果显示，洪水大幅度降低了河水中的DOC和CDOM浓度，并提高了溶解有机物(DOM)的芳香化程度。尽管洪水对DOM浓度产生了明显的稀释效应，但通过分析FDOM组成，进一步发现FDOM中不同组分对洪水的响应存在较大差异。FDOM短激发波长(230–235 nm)处的类蛋白质组分峰值在洪水期间出现高值；与此同时，长激发波长(280–285 nm)的类蛋白质组分和激发波长在345 nm处的类腐殖质组分峰值在洪水期间出现最低值。此外，与长江下游相比，珠江下游水体中往往具有较高的DOC和CDOM浓度、DOM芳香化程度以及CDOM分子量。本研究将有助于进一步了解珠江等世界大河DOM浓度和组成的变化规律和控制机制，以及揭示极端洪水对大河DOM动态变化产生的影响。 |
| 关键词: 珠江 洪水 溶解有机物 发色溶解有机物 荧光溶解有机物 |
| DOI：10.11693/hyhz20230700144 |
| 分类号: |
| 基金项目:国家自然科学基金, 42276217号; 国家自然科学基金联合重点项目, U2243207号 |
相关附件： （清水版）20230700144-傅芳敏-hyhz修改稿 （清水版）20230700144-傅芳敏-hyhz |
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| Impact of the basin flood in June 2022 on the concentrations and compositions of Dissolved Organic Matter in the lower Zhujiang (Pearl) River |
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fufangmin1, yaoailin1, mingyue2, Wang Xianye3, gaolei1
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1.State Key Laboratory of Estuarine and Coastal Research, East China Normal University ,Shanghai;2.State Environmental Protection Key Laboratory of Marine Ecosystem Restoration, National Marine Environmental Monitoring Center;3.The State Key Laboratory of Estuarine and Coastal Research
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| Abstract: |
| From November 2021 to October 2022, river water samples were collected monthly in Guangzhou section of the lower Zhujiang River, and the concentrations and compositions of dissolved organic carbon (DOC), chromophoric dissolved organic matter (CDOM), and fluorescent dissolved organic matter (FDOM) were analyzed. During sampling period, the Zhujiang River basin encountered a “once in a century” flood in June 2022. Results showed that the flood significantly reduced the concentrations of DOC and CDOM in the river water, and increased the DOM aromaticity. Although floods had a significant dilution effect on DOC and CDOM, further measurements of FDOM composition revealed that different FDOM components had different responses to this flood. The peaks of protein-like components at the shorter excitation wavelength (230–235 nm) reached its high value during the flood period. At the same time, the peaks of protein-like component with longer excitation wavelength (280–285 nm) and humic-like component (with excitation wavelength at 345 nm) showed the lowest values. In addition, compared with the lower Changjiang River, the lower Zhujiang River generally showed higher concentrations of DOC and CDOM, DOM aromaticity, and molecular size. The study will improve our understanding of the control mechanisms on the variations of DOM concentrations and compositions in the large rivers of the world like the Zhujiang River, and to elucidate the impacts of extreme floods on the DOM dynamics in those large rivers. |
| Key words: The Pearl River flood dissolved organic matter chromophoric dissolved organic matter fluorescent dissolved organic matter |