潮汐对闽江感潮河段水体DOM含量及其光谱特征的影响  

The Influence of Tides on the Content and Spectral Characteristics of Dissolved Organic Matter in the Tidal Section of the Minjiang River

作　　者：林晓皓 陈瑶[1,2] 朱贵青 吴福忠 LIN Xiaohao;CHEN Yao;ZHU Guiqing;WU Fuzhong(Institute of Geography,Fujian Normal University,Fuzhou 350117,China;Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350117,China)

机构地区：[1]福建师范大学地理研究所,福州350117 [2]福建师范大学湿润亚热带生态-地理过程教育部重点实验室,福州350117

出　　处：《亚热带资源与环境学报》2024年第1期44-52,共9页Journal of Subtropical Resources and Environment

基　　金：国家自然科学基金项目(32171641)。

摘　　要：可溶性有机质(DOM)虽然只占生态系统中有机质的一小部分,但易被微生物利用,在河流生态系统的养分供应与物质循环中具有关键作用。感潮河段的水体可溶性有机质极易受到潮汐作用引起的径流变化影响,但目前对其仍缺乏必要认识。以闽江感潮河段(117 km)为研究对象,在巨潮日分析涨、落潮过程中水体可溶性有机质的含量及其光谱特征变化。结果表明,潮汐作用显著影响距河口20 km范围水体可溶性有机质的含量、结构、组成以及来源,涨潮阶段水体DOC含量的上升程度较落潮增加35.9%,水体CDOM浓度下降程度较落潮增加26.2%,涨潮期近河口可溶性有机质的分子量增加,而芳香化程度降低,内源性增强。综合分析表明,潮汐主要通过促进河水与海水混合的物理过程,影响水体环境、可溶性有机质含量及其稳定性,增强pH、电导率、盐度和溶解氧与可溶性有机质的相关性,但减弱水体温度与可溶性有机质的相关性。这些结果对于深入认识潮汐过程对河流生态系统的影响,了解感潮河段的物质循环规律具有一定的科学意义。Dissolved Organic Matter(DOM)only accounts for a small portion of organic matter in ecosystems,while it is easily utilized by microorganisms and plays a crucial role in nutrient supply and material cycling in river ecosystems.The dissolved organic matter in the water of tidal river sections is highly susceptible to the impact of tidal runoff changes,however there is still a lack of necessary understandings.Taking the tidal section of the Minjiang River(117 km)as the research object,the content and spectral characteristics of dissolved organic matter in the water during the rising and falling tide processes were analyzed on giant tide days.The results show that tidal effects significantly affect the content,structure,composition,and source of dissolved organic matter in water within a range of 20 km from the estuary.The increase in DOC content during the rising tide stage is 35.9%higher than that during the falling tide stage,and the decrease in CDOM concentration is 26.2%higher than that during the falling tide stage.During the rising tide stage,the molecular weight of dissolved organic matter near the estuary increases,while the degree of aromatization decreases and endogenous enhancement occurs.Comprehensive analysis suggests that tides mainly promote the physical process of mixing river water and seawater,affecting the water environment,dissolved organic matter content and stability,enhancing the correlation between pH,conductivity,salinity,dissolved oxygen and dissolved organic matter,but weakening the correlation between water temperature and dissolved organic matter.These results have certain scientific significance for a deeper understanding of the impact of tidal processes on river ecosystems and for understanding the material cycling laws of tidal river sections.

关 键 词：潮汐作用 闽江 感潮河段 可溶性有机质 紫外-可见光谱 

分 类 号：X522[环境科学与工程—环境工程]