基于现场光谱的潮滩表层沉积物叶绿素-a含量遥感模式

Using In-Situ Reflectance to Monitor the Chlorophyll Concentration in the Surface Layer of Tidal Flat

提出了一种可实现潮滩表层叶绿素的现场快速、无损的光学检测方法。利用反射率光谱对我国潮滩表层沉积物叶绿素-a浓度进行了观测试验。基于高光谱650,675及700nm各波段的反射率,提出了用于叶绿素浓度反演的归一化底栖微藻差异指数(NDI-MPB)、及可消除呈直线或近似直线变化的背景噪声光谱的反射谷深度(T-depth)模型。研究结果表明,NDI-MPB指数与表层沉积物(3mm)中的叶绿素-a浓度(2.22～49.36mg.m-2)有极好的线性相关性(r>0.99);以叶绿素-a浓度表征底栖微型藻类生物量,NDI-MPB可用于潮滩表层底栖微型藻类生物量的遥感监测。

An optical monitoring method is proposed for the rapid,non destructive measurements of chlorophyll concentration（Chl-a）in the surface sediments of emerged tidal flat,and it can be further applied in remote sensing work.Hyperspectral reflectance of intertidal sediments were measured in day time at the tidal flats of the Sishili Bay,the Northern Yellow Sea,and surface sediments（3mm）were sampled for the in-door measurements of Chl-a.On the basis of the reflectance at 650,675and 700 nm,the indices of normalized difference index of microbenthos（NDI-MPB）and trough depth（T-depth）were proposed for the measurements of microphytobenthos biomass.T-depth can be used to remove the linear background spectral noises and indicate the existence of microphytobenthos;Good linear relationship was observed between NDI-MPB and Chl-a content in sediments（2.22～49.36mg.m-2,r0.99）,which may be used to monitor the biomass of microphy to benthos.