闽江下游有机碳及CDOM的季节动态  

Seasonal Variations of Organic Carbon and CDOM in the Lower Reaches of Min River

作　　者：钱伟[1,2,3] 江淼华 黄佳芳 李小飞[1,2,3] 陈莹[1,2,3] 胡文钦 仝川[1,2,3] QIAN Wei;JIANG Miaohua;HUANG Jiafang;LI Xiaofei;CHEN Ying;HU Wenqin;TONG Chuan(Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350007,China;Research Centre of Wetlands in Subtropical Region,Fujian Normal University,Fuzhou 350007,China;School of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China;Department of Geography,Ocean College,Minjiang University,Fuzhou 350108,China)

机构地区：[1]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350007 [2]福建师范大学亚热带湿地研究中心,福州350007 [3]福建师范大学地理科学学院,福州350007 [4]闽江学院海洋学院地理科学系,福州350108

出　　处：《亚热带资源与环境学报》2020年第3期1-8,共8页Journal of Subtropical Resources and Environment

基　　金：国家自然科学基金面上项目(41877335);福建省教育厅中青年教师教育科研项目(JT180071);福建师范大学大学生创新创业训练计划项目(cxxl-2019232)。

摘　　要：有机碳及有色溶解有机物(Chromophoric Dissolved Organic Matter,CDOM)是陆海物质传输的重要组成部分。通过对不同季节闽江下游的水样进行采集与分析,结果表明:闽江下游有机碳变化范围在136~295 mol·L^-1,溶解态有机碳(Dissolved Organic Carbon,DOC)占闽江有机碳的比例最大,但在调查期内月流量最高的2014年5月,颗粒态有机碳(Particulate Organic Carbon,POC)含量超过DOC。CDOM呈现显著的季节变化特征,秋季和冬季CDOM含量较低,春季和夏季含量较高;通过平行因子模型识别三维荧光光谱数据集中4个荧光组分,分别为:类腐殖质组分C1(270,360/450 nm),C2(240,320/422 nm),类蛋白组分C3(230,280/328 nm)和有机污染物组分C4(<200/382 nm)。样品的腐殖化指数(HIX)可有效地指示水体类腐殖质来源的季节变化特征;自生源指数(BIX)在秋、冬季较高而夏季较低,与类蛋白组分的季节变化一致。颗粒有机碳含量为1.12%~4.76%,存在明显的季节变化,随着颗粒物减少,颗粒中有机碳含量呈现缓慢增加趋势。闽江有机碳含量、有色溶解物质的光谱特征呈现显著的季节变化,对下游河口、近岸的生物地球化学过程影响有待进一步研究。The transport of organic carbon including chromophoric dissolved organic matter(CDOM),from river to coastal zone is of importance in linking land and ocean.The organic carbon concentrations varied between 136~295 mol·L^-1.DOC was dominant in the lower reaches of Min River,while the concentration of particulate organic carbon overwhelmed the DOC in May 2014 when the largest runoff occurred during surveys.Meanwhile spectroscopies of CDOM display substantial seasonality,the absorption was relatively lower in autumn and winter,and higher in spring and summer.Fluorescence excitation-emission matrices data set were decomposed into four components with parallel factor analysis,resulting in two humic-like components C1(270,360/450 nm),C2(240,320/422 nm),one protein-like C3(230,280/328 nm)and one xenobiotic-like component C4(<200/382 nm).Moreover,humification index(HIX)effectively indicated seasonal variations of humic substance.The autotrophic index(BIX)also displayed relatively higher values in autumn and winter while lower values in spring and summer,showing similar temporal pattern with protein-like florescence component.Concentrations of particulate organic carbon(POC)ranged from 1.12%~4.76%of total suspended solid(TSM)while lower TSS possessed slightly higher POC content within intra-annual scale.The impact of the biogeochemical processes in the downstream and estuary resulted from this prominent seasonality of organic carbon content and CDOM needs further study.

关 键 词：有色溶解有机物 三维荧光光谱 平行因子分析 闽江 

分 类 号：X522[环境科学与工程—环境工程]