| 基于生物光学模型的二类水体光学活性物质估算：以晋江下游河段为例 |
| 摘要点击 2299 全文点击 1600 投稿时间：2008-06-21 修订日期：2008-09-02 |
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| 中文关键词 光学活性物质 吸收系数 后向散射系数 水面下反射率 |
| 英文关键词 optically active substances absorption coefficient backscattering coefficient sub-surface irradiance reflectance |
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| 中文摘要 |
| 水体中各组分对光谱的吸收和散射构成了水体的固有光学特性，是生物光学模型的重要参数，是建立水质遥感半分析模型的基础.目前该方法多应用于湖泊水质监测，很少用于河流.因此, 本研究以福建晋江下游河段为例, 探讨水面下反射率R(0-)与光学活性物质之间的关系，并建立了光学活性物质的估算模型.结果表明，利用R(0-)753与总悬浮物浓度、R(0-)702/R(0-)680与浮游植物色素浓度、R(0-)670/R(0-)423与CDOM吸收系数分别建立的估算模型能取得理想的效果，其决定系数分别是0.953、 0.820 5和0.621 3，对应的相对误差分别是6.1%、 21.87%和22.18%.三者中以悬浮物浓度的反演精度最高，然后依次为浮游植物色素浓度和CDOM.主要原因在于浮游植物色素的浓度相对较低，光谱信号较弱；CDOM的特征光谱波段很窄，而且该波段内的R(0-)受到其它２种物质存在的影响. |
| 英文摘要 |
| The water's Inherent Optical Properties (IOPs), including absorption and scattering coefficients of water components, are the essential parameters for bio-optical model and retrieval of water quality using the semi-analytical method. Nevertheless, the application of the bio-optical model in river water studies is still very rare. Therefore, taking the lower Jinjiang River of Fujian, SE China as an example, this study measured and calculated the bio-optical properties of river water and concentrations of optically active substances based on in situ water samples collected from river in 2007. It shows that R(0-)753, R(0-)702/R(0-)680 and R(0-)670/R(0-)423 can be used to estimate total suspended solids (TSS) concentration, phytoplankton pigment (PP) concentration and the CDOM absorption at 440nm, respectively. The determination coefficients (R2) of the retrieval model of TSS, PP and CDOM are 0.953, 0.820 5 and 0.621 3, respectively. The corresponding relative errors of the models (RE) are 6.1%, 21.87% and 22.18%. The results show that the model for estimating TSS can achieve the highest accuracy, the PP-estimating model has the second highest accuracy and the CDOM-estimating model has the lowest. The relatively lower concentration of phytoplankton pigments, narrow characterized spectral range of CDOM and influence of CDOM's R(0-) by TSS and PP within this spectral range contributed to their relatively lower accuracy. |
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