太湖梅梁湾下行漫射衰减系数的特征分析  

Characteristic Analysis of the Fluctuation of the Downwelling Diffuse Attenuation Coefficient in Meiliang Bay of Taihu Lake

作　　者：赵巧华[1,2] 王鑫[1] 李俊生[3] 张运林[2] 

机构地区：[1]南京信息工程大学,环境科学与工程系,江苏南京210044 [2]中国科学院,南京地理与湖泊研究所,北京100101 [3]中国科学院,遥感应用研究所,江苏南京210008

出　　处：《遥感学报》2008年第1期128-134,共7页NATIONAL REMOTE SENSING BULLETIN

基　　金：南京信息工程大学校内基金(编号:y512);中国科学院方向性项目(编号:KZCX3-SW-350);国家自然科学基金(编号:40501078)联合资助

摘　　要：水体下行漫射衰减系数(Kd)不仅反映了水质的信息,而且是生物-光学模型中的关键参数,因而受到了广泛的关注。本文基于太湖梅梁湾水下光场的数据,分析了不同波长Kd的波动性随水深的变化特征,结果表明:由于水体表面波的作用,在60 cm以上,Kd随深度呈现较强烈的震荡现象,而到60 cm以下,随着光子的行程增大,介质散射对光场的改变趋于明显,造成该震荡幅度减弱,趋于稳定状态,甚至呈现出光场的渐进态特征。且在0—60 cm的区域,下行漫射衰减系数的波动程度与水体的吸收特性呈现明显的线性相关,即水体的吸收作用突显了表面波的效应。该水体中非藻类颗粒物和黄质具有对短波光强烈吸收的特性,减弱了介质散射使光场漫射比例提高的作用,加强了表面波对水下光场的扰动作用,使得相对长波而言,短波的Kd随水深呈现出相对较大的震荡现象。The downwelling diffuse attenuation coefficient(Kd) indicates the information of water quality.It is also key parameter of bio-optical model and attracting more and more attentions.Based on the data of light field under water in Meiliang bay of Taihu lake,the changes of Kd with water depth is analyzed.The results show that,Kd takes on significant fluctuation with the depth above 60cm,which is caused by the surface waves of water.But the fluctuation with depth weakens,and approximately levels off,even showing the characteristic of asymptotic light fields below 60cm,because the effect of scattering is gradually significant.In the region of 0—60cm,there is significant linear correlation between the degree of fluctuation of downwelling diffuse attenuation coefficient and the absorption of water,namely,the absorption of water strengthens the effect of surface wave on the light fields in water.The Kd of shortwave takes on evident fluctuation with the depth compared with that of longwave,because The detritus and CDOM in water significantly absorbs the radiation of shortwave,lowers diffuse light,and intensifies the effect of focusing or defocusing of surface waves.

关 键 词：下行漫射衰减系数 深度 散射 吸收 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置] X87[自动化与计算机技术—控制科学与工程]