李家河水库上游水体溶解性有机物组分与来源

Dissolved organic matter components and sources in upstream of Lijiahe Reservoir

以李家河水库上游水体为研究对象,运用三维荧光光谱法解析水体溶解性有机物(DOM)的来源和特性,并探讨了DOM组分干湿季变化特征及影响因素.结果表明,李家河水库上游水体DOM由3个荧光组分组成,分别为类络氨酸(220nm,270nm/300nm)、UVA类腐殖质(250nm/430nm)和类色氨酸(225nm,280nm/335nm),其中类络氨酸为主要组分,但其含量干湿季变化不大,而UVA类腐殖质和类色氨酸含量呈现出显著的季节差异.荧光特征指数表明,李家河水库上游水体DOM的来源具有显著的陆源特征,其特征在湿季更加显著.水体DOM各荧光组分在干湿季均与TP呈正相关;在湿季,类络氨酸组分与Chl-a、浊度和CODMn呈正相关,而在干季无相关性.UVA类腐殖质与DOC在干湿季均存在正相关关系,且在湿季相关性(P<0.01)大于干季(P<0.05).类色氨酸与CODMn相关性也表现出湿季(P<0.01)大于干季(P<0.05)的特征.

The source and characteristics of dissolved organic matter(DOM)in upstream waters of Lijiahe Reservoir were analyzed by three-dimensional fluorescence spectrometry,and the seasonal variation characteristics and influencing factors of DOM components were discussed.The results showed that the DOM of the upper reaches of the Lijiahe Reservoir consists of three fluorescent components,namely tyrosine(220nm,270nm/300nm),UVA humus(250nm/430nm)and tryptophan(225nm,280nm/335nm).Among them,tyrosine is the main component,but its content does not change much in the dry and wet seasons,while the UVA humus and tryptophan content showed significant seasonal differences.The fluorescence characteristic index indicated that the source of DOM in the upstream water of Lijiahe Reservoir has significant terrestrial characteristics,and its characteristics are more significant in the wet season.The fluorescent components of DOM in water body were positively correlated with total phosphorus in dry and wet seasons.In the wet season,the tyrosine-like component is positively correlated with Chl-a,turbidity and CODMn,but not in the dry season.A positive correlation between UVA humus and DOC in dry and wet seasons existed,and the correlation in wet season(P<0.01)was more significant than that in dry season(P<0.05).The correlation between tryptophan and COD Mn also showed that the wet season(P<0.01)was stronger than the dry season(P<0.05).