珠江口水体表观光谱特性与类型分析

珠江口海域是典型的二类水体，光谱特性复杂，一直是国内学者研究的热点区域。本文基于2014年春（5月）、夏（8月）、秋（11月）、冬（2月）珠江口海域四个航次实测的表观光谱资料，探讨了珠江口海域遥感反射率的类型及时空分布特性。结果发现珠江口海域四季水体遥感反射率呈5大类型，每一类光谱都具有典型的区域性和季节变化特征，其谱峰在450~575 nm范围内随季节变化而移动，A类型常年分布在珠江口内，B类型冬春季节分布在珠江口外混合过渡类水体中，C类型主要分布在珠江口口门外水深较深的离岸海域，D类型春夏季在万山群岛附近海域出现，E类型与大洋水体的光谱特征类似。分析表明5种光谱类型的谱型变化趋势由不同的水质因子主导。该研究对深入探讨珠江口等我国近海二类复杂水体的光谱特性及其水色要素的遥感反演具有重要的参考价值。

Apparent spectral types and characteristics of Pearl River Estuary

With complex spectral characteristics, the Pearl River Estuary sea area belongs to typical Case Ⅱ waters, which has always been a hot area researched by domestic scholars.Based on the apparent spectral data detected from four voyages in Pearl River Estuary in spring (May), summer (August), autumn (November) and winter (February) in 2014, this paper illustrated the types of remote sensing reflectivity and its spatial and temporal distribution characteristics.The results suggest that there are five types of remote sensing reflectivity in the four seasons in Pearl River Estuary, and each type of the spectrum has typical regional and seasonal variation characteristics.The peaks of the spectrum range from 450 nm to 575 nm, with the variation of the seasons, i.e., Type A perennially distributed in Pearl River estuary; Type B distributed in mixed transitional waters outside the Pearl River Estuary in winter and spring; Type C is mainly distributed in the offshore area with deeper depth; Type D distributed in the waters near Wanshan Islands in spring and summer and Type E similar to that of Case Ⅰ waters.The analyses show that the spectral pattern of the five spectral types are dominated by different water quality parameter.The research has shed new light on remote sensing retrieval of color elements and further exploration of the spectral characteristics in our coastal Case Ⅱ waters such as Pearl River Estuary.