新安江水库夏季CDOM吸收光谱特征及来源分析

为探讨夏季新安江水库有色可溶性有机物(CDOM)吸收光谱特征、空间分布及潜在来源,于2013年7月份在新安江水库采集了53个表层水样,分析了CDOM吸收系数a(350)、比吸收系数a*(350)和光谱斜率S值的空间分布规律及CDOM吸收系数与水质参数的相关关系.结果表明:通过系统聚类分析,夏季新安江水库CDOM吸收系数空间分布可划为3类,吸收系数大小呈现出A类区(西北河流区)>B类区(库心区及东北库区)>C类区(西南库区及东南库区)的规律,空间分布与CDOM比吸收系数相似而与S值相异.CDOM吸收系数a(350)与叶绿素a(Chla)浓度、浮游植物吸收系数及悬浮物浓度存在极显著性正线性相关,表明夏季新安江水库CDOM主要来源于浮游植物新陈代谢及降解产物.

Absorption characteristics and sources analysis of CDOM in Xin'anjiang Reservoir in summer

To investigate the spectral absorption characteristics, spatial distribution and source of colored dissolved organic matter (CDOM), 53 surface water samples were collected from Xin'anjiang Reservoir in July, 2013. The spatial distribution of CDOM absorption coefficient at 350nm a(350)], carbon-specific CDOM absorption coefficient a*(350)], the spectral slope (S), as well as the relationships between CDOM and water quality parameters were studied. Using hierarchical cluster analysis, we divided a(350) into three districts (A, B, and C districts). a(350) decreased from north western area (A district) to the central reservoir and the north eastern area (B district), and to the south western area and the south eastern area (C district). The distribution pattern of a (350) was similar to the distribution of a*(350) but different from that of S. Significantly positive linear correlations between a (350) and chlorophyll a concentration, phytoplankton absorption coefficient and suspended solids indicated a critical contribution of phytoplankton metabolism and degradation products of CDOM.