长江口及邻近海域水体反射率的模拟

Modeling of seawater reflectance in the Yangtze Estuary and the adjacent sea

通过对2009年8月和11月水体光学特性的分析发现:长江口邻近海域夏秋两季反射光谱曲线由于悬浮泥沙、浮游植物以及黄色物质的影响呈现4种形状;叶绿素a浓度与浮游植物吸收系数可通过两种方式建立良好关系;将水体各组分光学特性参数化,并结合叶绿素a浓度与吸收系数的两种关系分别建立水体反射光谱参数模式,从而可以对水体遥感反射光谱进行模拟,模拟曲线的均方根误差分别为0.004 4和0.004 5.在模式的建立中,根据长江口海域水体组分浓度的分布状况,对悬浮泥沙浓度以及叶绿素a浓度进行分类,得到不同水体组分浓度下反射率光谱曲线;然后分别获得模式参数并进行模拟,得到的反射率模拟曲线与实测相对均方根误差为0.003 5,具有更高的模拟精度.

The optical properties of the Yangtze Estuarine waters were discussed based on two investigations conducted respectively in August and November of 2009. It was found that the waterleaving reflectance spectra in August and November presented four types caused by different chlorophylla concentrations, suspended sediment concentrations and colored dissolved organic matters （CDOM）. The relationships between chlorophylla concentration and absorption coefficient of the pigment particles were built by two ways, and two models used to simulate the reflectance spectra were established by using the parameterized optical properties, the RMSE of these models being 0. 004 4 and 0. 004 5, respectively. The accuracy of the model can be improved by classifying the concentrations of chlorophylla and suspended sediment, the RMSE was improved to 0. 003 5.