浒苔分布的大范围遥感监测是应对浒苔灾害的迫切要求。对于海面漂浮浒苔,已基本实现了有效的光学遥感监测。针对水下悬浮浒苔情形,开展了海面光谱响应的辐射传输模拟研究,分析了海面光谱随浒苔厚度、悬浮深度、水体浑浊度以及环境条件的变化规律。研究发现:随浒苔悬浮深度、水体浑浊度的增加以及浒苔厚度的减小,海面光谱所包含的浒苔信息减弱,海水颜色(光谱主波长和纯度)也随之发生变化;水气界面粗糙度、云覆盖程度以及太阳天顶角等环境因素的影响可忽略;可引起海面光谱变化的浒苔最大悬浮深度,在黄海清洁水体中约为30 m,在浑浊水体中约为1 m。
The accumulation of Enteromorpha prolifera in huge amount in the Yellow sea in June, 2008 draws the attention from all over the world. It is an urgent requirement to monitor the wide range of Enterornorpha prolifera distribution by remote sensing. As to the Enteromorpha prolifera floating on the sea surface, effective monitoring by optical remote sensing has been basically achieved. As far as the underwater suspended Enteromorpha prolifera is concerned, the present paper carried out the radiative transfer simulation research on the above water spectral response, its variation with the suspending depth, the water turbidity and environmental conditions. It was found that with the increase in Enteromorpha prolifera suspending depth and water turbidity as well as the decrease in the thickness of Enteromorpha prolifera, the Enteromorpha prolifera information contained in the surface spectra would decrease. The influence of environmental factors such as water-gas interface roughness, cloud cover extent and sun zenith angle on the underwater suspended Enteromorpha prolifera spectra can be ignored. The maximtma Enteromorpha prolifera depth that can cause surface spectrum changes is about 30 m in clean water and about 1 m in turbidity water.