基于R_(rs)(0^-)太湖秋季水体固有光学量分类研究

Classification Research of Inherent Optical Property Base on R_(rs)(0^-) in Autumn Taihu Lake

基于2007年11-12月太湖全湖40个样点采集的固有光学属性、表观光学属性和水质参数等数据,选择受光线条件影响最小的水表面以下反射率Rrs(0-)作为分类依据,探索建立太湖水体固有光学属性分类体系。结果表明,利用Rrs(0-)能较好地将太湖水体固有光学属性分为4类,其中吸收系数为:Class1:色素和非色素物质共同作用,同时黄质占有重要地位;Class2:色素和非色素物质共同作用,其中色素物质作用偏强,但非绝对主导因素,同时黄质作用较弱;Class3:非色素物质吸收系数主导类型,色素和黄质作用较低;Class4:色素、非色素物质和黄质共同作用。平均散射系数及其线性衰减斜率4种类型的大小顺序分别为:Class2>Class3>Class1>Class4和Class2<Class3<Class1<Class4。4种类型的后向散射系数在<588nm波长范围内大小顺序为:Class2>Class3>Class1>Class4,而在>588nm波长范围内,难以区分4种类型的后向散射系数。

Based on the measurement and calculation parameters such as inherent optical properties,the apparent optical properties and water quality parameters of 40 sites on the whole Taihu Lake during November to December in 2007,choosing the remote sensing reflectance Rrs（0-）just under water surface that the smallest light conditions affect on it classification results as a basis for the inherent optical properties class,the paper gropes for the method to establish classification system of inherent optical properties in Taihu Lake.Results show that,using Rrs（0-）the inherent optical properties of Taihu Lake can be classified into four categories preferably,the four categories of absorption coefficients：Class1：pigment and non-pigment material has the common role,while yellow substance also occupies an important position;Class2：pigment and non-pigment material has the common role,but pigment material is stronger than non-pigment occupying an important position,but not the dominant factor,while the effect of yellow substance is much weaker;Class3：non-pigment material is the dominant factor,the effect of pigment and yellow substance is low;Class4：pigment,non-pigment material and yellow substance has the common roles.The order of four types of average scattering coefficient and linear attenuation slope are：Class2〉Class3〉Class1〉Class4and Class2〈Class3〈Class1〈Class4,respectively.In〈588nm wavelength range,the order of four types of back-scattering coefficient is：Class2〉Class3〉Class1〉Class4,In〉588nm wavelength range,it is difficult to distinguish the four types of back-scattering coefficient.