太湖水体后向散射特性模拟

Simulation of backscattering properties of Taihu Lake

为研究太湖水体后向散射系数的光学特性，利用太湖实测数据和半分析方法与光学闭合（OpticalClosure）原理，对太湖水体的后向散射系数进行模拟，在此基础上对其光学特性和影响因子进行分析。研究结果表明：由于悬浮物浓度的差异，使得太湖水体后向散射系数具有明显的差异性，后向散射主要由无机悬浮物引起，浮游藻类对后向散射系数的贡献较小；由于悬浮物来源不同，使得悬浮物粒径分布、形状以及组成成分不同，导致太湖水体单位后向散射系数存在一定变化；以550nm作为参考波段对太湖后向散射系数进行参数化，得出该波段后向散射系数与悬浮物浓度具有很好的线性关系，其指数在1．32-2．8之间变化，平均值为2．09。

In order to study the properties of the backseattering coefficient in Taihu Lake, quasi-analytical algorithm and op- tical closure are used in this paper to stimulate the backscattering coefficient of Taihu Lake according to the field measurement data, and its properties and influence factors are also analyzed synchronously. The results indicate that, because of the varia- tion of the suspended sediment concentration, the backscattering coefficient varies over all sampling stations, and the backscat- tering is mainly caused by the inorganic suspended sediment in Taihu Lake, while the contribution of phytoplankton is slight. The specific backscattering coefficient also varies among the stations, and the variation mainly results from the difference of suspended particle size, shape and composition. Taking 550 run as reference to parameterize the backscattering coefficient of Taihu Lake, we can find that there is a greater linear relationship between the backscattering coefficient and the suspended sediment concentration, and the exponent index n ranges from 1.32 to 2.8 with a average value of 2.09.