水库水体近红外反射峰与叶绿素含量之间的关系初探  

The NIR peak of the reflectance spectrum associated with chlorophyll in the pool waters: preliminary results

作　　者：杨敏[1] 商少凌[1] 汪文琦[1] 林供[1] 王郝京[1] 

机构地区：[1]厦门大学近海海洋环境科学国家重点实验室,厦门361005

出　　处：《湖泊科学》2009年第2期228-233,共6页Journal of Lake Sciences

基　　金：国家863计划项目(2006AA09A302;2008AA09Z108);国家自然科学基金项目(40521003)联合资助

摘　　要：2007年8月至2008年9月,对厦门两个淡水水体(芙蓉湖、厦大水库)的叶绿素浓度和遥感反射率(Rrs)进行了连续观测.在叶绿素浓度6-322mg/m3的范围,Rrs光谱出现显著的近红外反射峰,中心位置在700-710nm之间,较之通常的荧光峰中心(683nm)向长波方向偏离.该峰在厦大水库始终出现在700nm,但在芙蓉湖存在时间变化,随着叶绿素浓度的增加,由705红移到710nm.由此,仿MODIS荧光高度(FLH)的定义,定义该峰的高度(简写为REH),对于水库和芙蓉湖中心波段分别确定为700和710nm.REH与叶绿素浓度呈现显著相关,芙蓉湖REH=0.016lg(chl)-7.8×10-6(R2=0.79,n=41),水库REH=0.0001chl+0.0002(R2=0.74,n=32).可见对于高散射的淡水藻华水体,可以并且需要通过改进FLH的波段选择,基于更长波段处的近红外峰的高度探测叶绿素浓度.Remote sensing reflectance （Rrs） and concurrent chlorophyll-a （Chl） concentration were measured from August 2007 to September 2008 in two pools （Furong Pool and XMU Reservoir） in Xiamen, Fujian. During most of the time, the measured Rrs spectra for Chl ranging between 6 to 322mg/m^3 show a prominent secondary peak in the far-red region of the spectrum. This is not from fluorescence alone, but appears to be caused by the red edge. Following the estimation of MODIS Fluorescence line height （FLH）, we defined a red edge height （REH） during 705 and 710nm. It was found that REH was highly correlated with Chl. The relation functions are REH-0.0161g（chl）-7.8×10^-6（R^2=0.79, n=41） in the Furong Pool, and REH=0.0001ch1＋0.0002 （R^2=0.74, n=32） in the XMU Reservoir. Our results suggest that the red edge may provide a good tool for researching and management in order to study and monitor the algal blooms in waters where there are dense suspensions of algal cells.

关 键 词：近红外反射峰 叶绿素 遥感反射率 淡水 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]