鹤地水库有色溶解性有机物来源与组成特征
- Characterizing sources and optical composition of chromophoric dissolved organic matter in Hedi Reservoir
- 基金项目：广东省水利科技创新项目(2024-01),广州市科技计划项目(SL2022A04J01045)
- 摘要：鹤地水库作为集中式饮用水源地以及环北部湾水资源配置工程重要节点,水环境与水生态变化对当地用水安全影响重大。有色溶解性有机物(CDOM)是水体有机物重要组成部分,其来源与组成不仅影响水质,也反映污染源特征。因此研究CDOM来源与组成特征对保障鹤地水库供水安全的管理工作有着重要支撑作用。在枯、平与丰水期采集鹤地水库水样,运用吸收光谱与荧光光谱等揭示鹤地水库CDOM的组成与来源的时空特征。结果显示,鹤地水库CDOM库中,陆源类腐殖质(32.2%~38.4%)、微生物源类腐殖质(26.6%~32.1%)与类色氨酸(25.2~41.2%)贡献均衡,意味着鹤地水库受外源输入与内源自生的协同影响。时空分布特征显示上游九洲江、长径河与塘拱河是类腐殖质的主要贡献来源,自河口至库心类腐殖质递减；类色氨酸则随Chl a的分布特征而变化。结合相关性分析与冗余分析结果,类腐殖质与NH4+相伴输入(p<0.05),类色氨酸与藻类活动密切相关(p<0.05)。相关研究结果可为鹤地水库营养状态判断与污染物质溯源提供有效指示作用。
- Abstract：As a centralized drinking water source and a crucial node in the Beibu Gulf Water Resources Allocation Project, changes in the water environment and ecology of the Hedi Reservoir significantly impact local water security. Chromophoric dissolved organic matter (CDOM) is an essential component of aquatic organic matter. Its sources and composition not only influence water quality but also reflect pollution characteristics. Therefore, studying the sources and compositional characteristics of CDOM is crucial for ensuring the safety of the Hedi Reservoir"s water supply. Water samples from the Hedi Reservoir were collected during dry, normal, and wet seasons. Utilizing absorption and fluorescence spectroscopy, the spatial and temporal characteristics of CDOM composition and sources in the Hedi Reservoir were elucidated. The results indicated that terrestrial humic substances (32.2%-38.4%), microbial humic substances (26.6%-32.1%), and tryptophan-like substances (25.2%-41.2%) contributed almost equally to the CDOM pool of the Hedi Reservoir, suggesting that the reservoir is influenced by both external inputs and internal production. The spatial and temporal distribution patterns revealed that the Jiuzhou River, Changjing River, and Tanggong River upstream are the primary sources of humic substances, which decrease from the estuary to the reservoir center. In contrast, the distribution of tryptophan-like substances varied with the distribution of chlorophyll a (Chl a). Correlation analysis and redundancy analysis further indicated that humic substances are associated with NH4+ input (p<0.05), while tryptophan-like substances are closely related to algal activity (p<0.05). These findings provide effective indicators for assessing the nutritional status and tracing the sources of pollutants in the Hedi Reservoir.
