摘要
基于2004年夏季水华暴发期和冬季在梅梁湾及大太湖各2次采样,分析了夏季、冬季CDOM的特征及其可能的来源,发现夏季CDOM吸收系数、叶绿素a浓度均明显高于冬季,DOC浓度、CDOM吸收系数a(355)的变化范围分别为5.17～12.42 mg/L、2.57～6.77 m-1,最大值均出现在冬季(12月15日)的直湖港入湖口。CDOM吸收系数与DOC浓度、定标后的荧光值一般都存在显著正相关,但夏季由于受浮游植物降解的影响,与DOC浓度和荧光的相关性明显低于冬季。表征CDOM组成和来源的参数比吸收系数、M值、S值存在显著的季节差异,夏季吸收系数a*(355)值明显要大于冬季,而S值、M值则要小于冬季。夏季水华暴发时CDOM吸收系数与叶绿素a浓度空间分布较为一致,吸收系数与叶绿素a浓度存在正相关,浮游植物降解产物可能是水体中CDOM的重要来源;相反,冬季CDOM吸收系数呈现从梁溪河入湖口、湾内往湾口递减的趋势,其来源可能主要以陆源为主,受入湖河流的影响较大。
The feature Chromophofic dissolved organic matter （CDOM） and its source in Meiliang bay and Da Taihu lake in Taihu Lake are analysed based on every 2 time＇s samplings in summer with algal bloom and winter. CDOM absorption coeffi cients and chlorophyll a concentration are significant higher in summer than winter. The DOC concentration and the CDOM absorption coefficients a （355） are in the range of 5.17 - 12.42 mg/L, 2.57 - 6.77 m^- 1, respectively, with the maxima at the mouth of Zhihu fiver on Dec. 15. Significant positive correlations are generally found within a（355）, DOC concentration and normalized fluorescence Fn （355）. The determination coefficients between a （355）, DOC concentrations and Fn （355） are sig- nificantly lower in summer than winter due to the phytoplankton degradation. As the parameters representing the CDOM composition and the source, the DOC-specific absorption coefficients a^＊ （355） are remarkably larger in summer than winter. However, M and S values are smaller in summer than winter with the seasonal variations. The spatial distribution of the CDOM absorption coefficients is similar to that of chlorophyll-a concentration in summer with algal bloom. A significant and positive correlation is found between a （355） and chlorophyll-a concentration, which shows that phytoplankton degradation is one of the potentially important sources of CDOM. By contrast, no significant correlation is found between a （355） and chlorophyll a concentration in winter. The CDOM absorption coefficient generally decreases from the mouth of river to the inlet and outlet of Meiliang bay, which shows that river terrestrial input is the potentially main source of CDOM.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2007年第3期415-423,共9页
Advances in Water Science
基金
江苏省自然科学基金资助项目(BK2006580)
中国科学院优秀博士学位论文
院长奖获得者科研启动专项资金资助项目
中国科学院南京地理与湖泊研究所所长科研专项基金资助项目~~
