摘要
针对2005年8月、11月及2006年2月、5月太湖31个采样点的水样,测定了其中黄质（chromophoric dissolved organicmatter）和颗粒物的吸收系数.通过次氯酸钠漂白法及数值分离法,将颗粒物吸收系数分离为藻类颗粒物及非藻类颗粒物的吸收系数,并对2种结果进行了比较.同时分析了太湖水体介质吸收有效光合辐射能量的谱特征及其季节变化.结果表明,水体中的绝大部份光合有效辐射能量主要由黄质和非藻类颗粒物所获取,对夏季的400-473nm、秋季的400-461nm、冬季的400-476nm、春季的400-569nm的能量而言,黄质的吸收贡献大于非藻类颗粒物;而在其余波段中,非藻类颗粒物的吸收贡献相对较大.藻类颗粒物的吸收贡献谱在490nm、676nm左右处存在2个主峰区,620nm左右处存在一次峰区,且该次峰在夏、秋季尤为明显,春季次之,冬季最小.藻类的吸收贡献也呈现出较为明显的季节特征,夏季吸收贡献最大达到22.1%,平均为16.4%;秋季最大为18.4%,平均为13.1%;春季最大为15.1%,平均为9.7%;冬季最大为10.1%,平均为6.8%.由于太湖颗粒物的吸收系数主要由非藻类颗粒物决定,因而用次氯酸钠漂白法从中提取藻类颗粒物的吸收系数会造成较大的误差,而改进的数值分离法在此基础上有了一定的提高.
In Aug.and Nov.,2005,and Feb.and May,2006,the absorption coefficients of particles and chromophoric dissolved organic matter（CDOM）in Taihu Lake were measured,based on water samples from 31 fixed sampling locations.The spectral absorption of algal particles was separated from that of total particles by NaClO bleaching or numerical partitioning,and the results were compared.The spectral characteristics of the photosynthetically active radiation absorbed by the water samples were analyzed.Most of the photosynthetically active radiation was absorbed by the CDOM and non-algae particles.The absorption contribution of CDOM is larger than that of non-algae particles in the waveband 400-473 nm in summer,400-461 nm in autumn,400-476 nm in winter and 400-569 nm in spring,.For the other wavelengths,the opposite is observed.There are two main peaks at 490 nm and 676 nm and a smaller peak at 620 nm in the spectrum of algae absorption.The peak at 620 nm showed an obvious seasonal variation,being largest in summer and autumn,and smallest in winter.The absorption contribution of algae particles also showed obvious seasonal variation.The maximum values of the absorption contribution spectrum were 22.1% in summer,18.4% in autumn,15.1% in spring and 10.1% in winter.The average absorption contributions by algae were 16.4% in summer,13.1% in autumn,9.7% in spring and 6.8% in winter.The significant error may be caused by the partitioning method of the NaClO bleaching.The partitioning precision was improved by numerical computations because the absorption coefficient could be determined by that of non-algae particles.
出处
《环境科学学报》
CAS
CSCD
北大核心
2008年第9期1813-1822,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.40701168
40671138)
中国科学院创新战略行动项目(No.KZCX1-SW-12)~~
关键词
吸收贡献谱
藻类
非藻类
黄质
absorption contribution spectrum
algae
non-algae particles
CDOM
