Absorption characteristics of optically complex inland waters: Implications for water optical classification
Absorption characteristics of optically complex inland waters: Implications for water optical classification
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DOI：
10.1002/jgrg.20071
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发表时间：
2013-06
期刊：
影响因子：
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通讯作者：
Kun Shi;Yunmei Li;Lin Li;Heng Lu
中科院分区：
文献类型：
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作者：
Kun Shi;Yunmei Li;Lin Li;Heng Lu
在中国内陆沃茨中进行了多次生物光学测量，包括太湖[春季和秋季]、巢湖、滇池和三峡水库。分析了有色溶解性有机物（CDOM）、浮游植物和非藻颗粒物（NAP）的吸收特征及其在各沃茨总吸收中的相对贡献。所获得的结果表明，这些地区是具有代表性的光学复杂的内陆沃茨，其特征在于其吸收特性的强烈的区域变化。通过NAP和浮游植物对550和675 nm处总吸水量的相对贡献，将这些沃茨分为三种光学水类型，每种类型都具有特定的地球化学和光学性质。两种类型是不同的，对应的沃茨，是光学控制的NAP（I型）和浮游植物为主（III型）。第二类是相对光学混合沃茨的吸收性能控制的NAP和浮游植物。此外，澄清了三种分类的水类型之间的遥感反射率（Rrs）光谱的差异，以建立识别这些水类型的光学标准。在此基础上，MERIS图像的分类标准，它允许一个聚类每个Rrs光谱的三种类型之一，通过比较的MERIS图像的波段6，波段8，波段9的值。提出的标准，随后进行了利用MERIS图像的太湖水类型图。
Multiple bio‐optical measurements were conducted in inland waters of China, including Lake Taihu [spring and autumn], Lake Chaohu, Lake Dianchi, and Three Gorges Reservoirs. The variations in the absorption characteristics of chromophoric dissolved organic matter (CDOM), phytoplankton, and non‐algal particles (NAP) and their relative contributions to total absorption among these waters were analyzed. The obtained results indicated that these areas are representative of the optically complex inland waters characterized by strong regional variations of their absorption properties. By means of the relative contributions of NAP and phytoplankton to the total water absorption at 550 and 675 nm, these waters were classified into three optical water types, each one having specific biogeochemical and optical properties. Two of the types were distinct and corresponded to waters that are optically controlled by NAP (Type I) and dominated by phytoplankton (Type III). Type II was related to relatively optically mixed waters where the absorption properties are controlled by NAP and phytoplankton. Additionally, the differences in remote‐sensing reflectance (Rrs) spectra among the three classified water types were clarified to establish optical criteria for identifying these water types. On this basis, the classification criteria for MERIS images were developed, which allowed one to cluster every Rrs spectrum into one of the three water types by comparing the values from band 6, band 8, and band 9 of MERIS images. The proposed criteria were subsequently conducted to map the water types of Lake Taihu using MERIS images.