| 摘要: |
| 为探究补水型城市河湖人工湿地系统枯水期和丰水期溶解性有机质（DOM）的组成特征、来源及其与水质的关联性，以巢湖流域典型城市人工河湖湿地为研究对象。运用三维荧光光谱（EEMs）技术，结合平行因子分析法（PARAFAC）解析枯-丰水期湿地内水体DOM的含量组分变化和主要来源；分析常规水质指标pH、溶解氧（DO）、总磷（TP）、总氮（TN）、叶绿素a（Chla）和浊度的时空变化特征以及与DOM的关联性。研究结果表明：（1）PARAFAC识别出四种荧光组分，分别为紫外类富里C1、类色氨酸C2、类胡敏酸C3、类酪氨酸C4，DOM在丰水期荧光强度高于枯水期，水体DOM受内源和陆源的双重影响，以自生源为主；（2）受城市地表径流及夏季巢湖蓝藻爆发影响，各水质指标浓度的时空变化特征主要表现为丰水期高于枯水期、从上游到下游呈现先升高后下降趋势，枯水期时的生态补水和方兴湖湿地能够对水质具有改善作用；（3）水质理化指标、DOM组分和荧光指数相关性分析结果表明DOC与Chla、浊度和C4组分呈显著正相关（P ≤ 0.01）、TP与C1、C2和C3呈显著正相关（P ≤ 0.01），可见地表径流携带的有机污染物贡献了湿地中一部分DOM，浮游植物的内源产生是塘西河下游有机碳的重要来源。研究揭示了塘西河-方兴湖湿地DOM的荧光特征、组分来源、水期差异以及水质变化，为进一步探明城市河湖湿地生态系统DOM时空分布特性和来源以及生态补水对水质的影响等提供了基础资料。 |
| 关键词: DOM 人工湿地 光谱特征 巢湖 |
| DOI： |
| 分类号: |
| 基金项目:巢湖生物资源调查研究项目（2020-340181-77-01-037328）、安徽省自然科学基金优秀青年项目（2308085Y38）、安徽高校协同创新项目（GXXT-2023-081）和巢湖流域治理与高质量发展安徽省哲学社会科学重点实验室（皖教工委函〔2022〕558号） |
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| Sources analysis of dissolved organic matter and their correlation with water quality in ecological replenishment urban river-lake wetland systems |
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Ling Song,Yang Shenglin,Liu Xiaowei,Yuan Zhen,Yang Bo,Shang Qiannan,Zhong Tianyang,Zhang Ling
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Hefei University
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| Abstract: |
| In order to explore the composition characteristics, sources, and correlation with water quality of dissolved organic matter (DOM) in urban river and lake artificial wetland systems replenished with ecological flow, a typical urban artificial river and lake wetland in the Chaohu Basin was taken as the study case. Three-dimensional fluorescence spectroscopy (EEMs) technology combined with parallel factor analysis (PARAFAC) was used to analyze the changes in the content and main sources of dissolved organic matter (DOM) in the water body of wetlands during dry and wet seasons. The spatiotemporal variation characteristics of conventional water quality indicators including pH, dissolved oxygen (DO), total phosphorus (TP), total nitrogen (TN), chlorophyll a (Chlα), and turbidity were analyzed, as well as their correlation with DOM. The results indicated that: (1) PARAFAC recognized four fluorescent components, which were UV rich C1, tryptophan C2, humic acid C3, and tyrosine C4. The fluorescence intensity of DOM in the wet season was higher than that in the dry season, and the DOM in the water was influenced by both endogenous and terrestrial sources, of which endogenous sources were the main source; (2) Due to the influence of urban surface runoff and the blue algae bloom in Chaohu Lake in summer, the spatiotemporal variation characteristics of these water quality indicators were mainly higher in the wet season than those in the dry season, and their concentrations showed increased at upstream and then decreased at downstream. Ecological flow replenishment during the dry season and the wetland can play a role on the improvement of water quality; (3) The correlation analysis of water quality physicochemical indicators, DOM components, and fluorescence index showed that DOC was significantly positively correlated with Chlα, turbidity, and C4 components (P ≤ 0.01), and TP was significantly positively correlated with C1, C2, and C3 (P ≤ 0.01). It can be seen that terrestrial sources such as surface runoff has an impact on DOM, and the endogenous production of phytoplankton is an important source of organic carbon in the downstream of Tangxi River. The study revealed the fluorescence characteristics, component sources, water period differences, and water quality changes of DOM in the Tangxi River-Fangxing Lake wetland, providing basic data for further exploring the spatiotemporal distribution characteristics and sources of DOM in urban river lake wetland ecosystems, as well as the impact of ecological fowl replenishment on water quality. |
| Key words: DOM artificial wetlands spectral characteristics Chaohu Lake |
