基于2009年9月在滇池的野外采样,分析了滇池水体中光学活性物质的吸收特性及其空间分布、与水体组分浓度的关系、各光学活性物质吸收对总吸收的贡献率、滇池水体吸收特性与其他二类水体的异同性等.结果表明,总颗粒物吸收光谱曲线与浮游藻类吸收光谱曲线形状相似,浮游藻类吸收在总颗粒物吸收中占主导;440、624和675 nm处的浮游藻类吸收aph与叶绿素a浓度呈现显著正相关,蓝藻是滇池水体的优势藻种;滇池北部湖区藻类密集,富营养化程度较南部湖区严重.与其他二类水体的吸收特性相比,滇池水体既表现出相似性,又表现出一定的差异性.滇池各吸收特性的数值都落在之前二类水体的研究结果范围之中,这体现了相似性;而差异性主要表现在:①非藻类颗粒物吸收光谱曲线斜率Sd均值略高于其他二类水体;②有色可溶性有机物(chromophoric dissolved organic matter,CDOM)吸收光谱曲线斜率Sg均值相对其他二类水体偏小;③浮游藻类比吸收系数大致处于中间水平,造成浮游藻类比吸收不同的原因是其受不同地区、不同季节和浮游植物种群结构等的影响.
A field investigation in Lake Dianchi was carried out in November,2009,and a dataset including absorption coefficients and concentration of water components was collected.Absorption properties and its spatial distribution of Lake Dianchi have been systematically analyzed,the results show that: ① Absorption spectral curve of total particles(ap) are similar with that of phytoplankton(aph),which indicates that phytoplankton absorption dominates absorption of total suspended particles;② Significant relationships are found between aph(440),aph(624),aph(675) and concentration of chla,and cyanophyta dominats the quantity of the algae in water columns;③ There are more phytoplankton existed in northern lake than other areas because of higher level of eutrophication.Comparing with other water columns,discrepancies mainly appear as below: ①The mean value of slope of absorption spectral curve of non-algal particles(Sd) in Lake Dianchi is much bigger than that in other case-Ⅱ waters;② The mean value of slope of absorption spectral curve of chromophoric dissolved organic matter(CDOM) Sg in Lake Dianchi is much smaller than that in other case-Ⅱ waters;③ Specific absorption of phytoplankton(ap*h) at 440 nm and 675 nm is at intermediate level,and ap*h value is susceptible to different regions,seasons,population structure of phytoplankton and so on.