【摘要】 运用三维荧光光谱(excitation-emission matrices,EEMs)与平行因子分析模型(parallel factor analysis,PARAFAC)技术手段对南水北调东线枢纽湖泊洪泽湖、骆马湖两个水体中CDOM的来源组成特征进行分析.结果表明:①解析出两湖泊均得到3个荧光组分,陆源类腐殖质C1、类色氨酸C2和类酪氨酸C3.②两湖泊3种组分荧光强度在入湖河口附近明显高于其他水域,且丰水季节3种组分荧光强度均显著大于枯水季节(t-test,P <0. 01),其中陆源类腐殖质C1的荧光强度在丰水期最大.表明两湖水体CDOM来源与组成受上游水系来水量和水文过程的影响较大,尤其是陆源类腐殖质浓度的高低.③相关性分析得出,陆源类腐殖质C1与DOC浓度、吸收系数a(254)有极显著相关性(r~2=0. 60,P <0. 01; r~2=0. 88,P <0. 01),相关性高于其余两种组分,表明陆源类腐殖质为CDOM的主要来源.另外,陆源类腐殖质C1与SUVA、S275-295、IC∶IT具有很好的相关性(r~2=0. 49,P <0. 01; r~2=0. 61,P <0. 01; r~2=0. 93,P <0. 01),进一步说明了两湖泊CDOM来源与组成受陆源影响较大.洪泽湖、骆马湖CDOM来源与组成受到不同水文情景和入湖河流的影响,应加强丰水期对入湖河流的水质管理.更多还原

【Abstract】 Lake Hongze and Lake Luoma are two key lakes located in the middle reaches of the east line of the South-to-North Water Diversion Project. We attempted to unravel the sources and optical composition of CDOM for samples collected from these lakes using excitation-emission matrices( EEMs) and parallel factor analysis( PARAFAC). ① Three fluorescent components were obtained using PARAFAC,including a terrestrial humic-like C1,a tryptophan-like C2,and a tyrosine-like C3. The sources and optical composition of CDOM in the two lakes were,to a large extent,affected by upstream inflow. ② Specifically,fluorescence intensity( Fmax) of the three components C1-C3 in the inflowing river mouths of the two lakes was notably higher than in the other lake regions,and Fmaxof the three components during the flood season was significantly higher than during the dry season( t-test,P < 0. 01). During the flood season,the fluorescence intensity of the terrestrial humic-like component was the highest. This indicates that the source and composition of CDOM in the two lakes are greatly affected by the inflow from the upstream water system,and that the hydrological processes control the abundance and sources of CDOM,especially the terrestrial humic-like C1. ③ Significant positive relationships were found between the terrestrial humic-like C1 and the DOC concentrations and CDOM absorption a( 254)( r~2= 0. 60,P < 0. 01; r~2= 0. 88,P < 0. 01),and the correlation was higher than the other two components. This indicated that the terrestrial humic-like component was the main source of CDOM. In addition,the terrestrial humic-like C1 had a significant positive correlation with SUVA,S275-295,and the integration ratio of the fluorescence peak C to peak T( IC∶ IT)( r~2= 0. 49,P < 0. 01; r~2= 0. 61,P < 0. 01; r~2= 0. 93,P < 0. 01). It is further revealed that the source and composition of CDOM in the two lakes are greatly affected by land sources. This study reveals the response of CDOM source and composition in Lake Hongze and Lake Luoma to different hydrological scenarios and water transfer processes. Based on these results,the water quality management of the rivers entering the lake should be strengthened during the flood season.更多还原