内陆水体后向散射系数模拟研究  

Simulation of Backscattering Coefficients of Inland Waters

作　　者：张红[1] 李云梅[1] 黄家柱[1] 刘忠华[1] 徐祎凡[1] 徐昕[1] 郭宇龙[1] 檀静[1] 

机构地区：[1]南京师范大学教育部虚拟地理环境重点实验室,南京210046

出　　处：《环境科学》2011年第9期2522-2530,共9页Environmental Science

基　　金：国家自然科学基金项目(40971215);高分水环境遥感监测示范关键技术研究项目(E0203/1112-07)

摘　　要：在利用半分析方法结合光学闭合原理模拟水体后向散射系数的过程中,参考波长的选择对最终结果有较大影响.为了得出最佳参考波长的影响因子,利用太湖、巢湖和滇池的野外实测数据,对后向散射系数进行模拟,进而分析水体的最佳参考波长与其对应的水质参数浓度之间的变化规律.同时,建立了太湖、巢湖和滇池水体的后向散射系数曲线的幂函数光谱模型,获得的光谱指数分别为2.643±0.317、2.719±0.242、1.638±0.534.结果表明:①以整个湖泊为研究对象时,最佳参考波长随着湖泊水体中总颗粒物浓度cSPM、有机颗粒物浓度cSPOM和叶绿素浓度cCHL平均值的增大而向长波方向移动,太湖、巢湖和滇池水体的最佳参考波长分别为695、720和730 nm;②以单个湖泊的各个样点为研究对象时,由于内陆湖泊光学特性的复杂性,最佳参考波长的影响因子存在一定差异,但cSPM是一个共同的影响因子.此外,过高的cCHL将削弱水质参数浓度与最佳参考波长间的规律性;③在以无机颗粒物为主的水体中,后向散射系数与总颗粒物浓度之间存在更好的相关性,如在太湖水体中,R2达到0.852.When we simulated backscattering coefficients（bbp） using quasi-analytical algorithm and optical closure theory,it was found that the position of reference wavelength（λ0） had great impact on final results.In order to identify influence factors of the optimum λ0,datasets of Lake Taihu,Lake Chaohu and Lake Dianchi were used.After simulating of bbp,the relationship between optimum λ0 and associated water quality parameters were analyzed.Meanwhile,power functions were utilized to model bbp spectra,and spectral slope parameters of Lake Taihu,Lake Chaohu and Lake Dianchi were 2.643±0.317,2.719±0.242,1.638±0.534,respectively.The results indicate that： ①When the whole lakes are taken as objects of study,the λ0 should be changed to longer wavelength with the increasing of total suspended particle matter concentration（cSPM）,suspended organic particle matter concentration（cSPOM） and chlorophyll a concentration（cCHL）,the optimum location of λ0 of Lake Taihu is 695 nm,Lake Chaohu is 720 nm and Lake Dianchi is 730 nm;②When the samples in lakes are taken as objects of study,the influence factors are different due to the complexity of optical properties of inland waters.But it is to be noted that,cSPM is a key factor in common.Besides,the regularity mentioned above should be weakened with high cCHL.③ The relationship between bbp and cSPM is much stronger in the waters with suspended particles dominated by inorganic particles,in Lake Taihu,for example,relationship between these two variables is strong with R2=0.852.

关 键 词：半分析方法 光学闭合原理 后向散射系数 最佳参考波长 影响因子 

分 类 号：X87[环境科学与工程—环境工程]