三峡坝区水体吸收系数的特征研究

三峡坝区水体吸收系数的特征研究 Absorption coefficient characteristics of the Three Gorges Dam water 盖利亚 1 2 first-author 刘正军 1 张继贤 1 中国测绘科学研究院对地观测技术国家测绘局重点实验室 中国测绘科学研究院对地观测技术国家测绘局重点实验室 中国地质调查局水文地质环境地质调查中心 中国地质调查局水文地质环境地质调查中心 利用2007年11月在三峡坝区现场实测的水色要素吸收系数数据,对总颗粒物、浮游植物、CDOM的吸收系数特征进行了分析和研究。结果表明,对于三峡坝区区域的水体:（1）总颗粒物吸收光谱分布与非藻类的吸收光谱相似;（2）非藻类颗粒物的吸收系数随波长的变化分布接近指数衰减规律,且不同波段的吸收系数之间存在一定的关系;（3）多项式关系能较好的表达浮游植物吸收系数与叶绿素a浓度之间的关系;（4）分段函数能很好的表达CDOM的吸收系数特性,对500nm以下光谱的吸收呈现负指数衰减的规律,不同采样点拟合精度R2接近1;501—700nm波段范围的光谱曲线采用多项式能进行很好的拟和,且拟合精度R2达到95%以上。 The absorption coefficient of water color constituents is an inherent optical parameter. It is the main factor which influences the distribution of the water optical field, and plays a very important role in the researches of water optics remote sensing. This paper analyses the absorption coefficient characteristics for particle matter, phytoplankton and colored dissolved organic matter（CDOM）, using the absorption coefficient of water color constituents in situ measured at the Three Gorges Dam in April, 2007. The results show that, for the Three Gorges Dam water: （1） the absorption spectrum of non-algal particles is similar with that of total particle matter; （2） the absorption coefficient of non-algal particles decreases power exponentially from short to long wavelength, and the absorption coefficient in different bands has a definite relationship; （3） the absorption coefficient of phytoplankton has a better polynomial relationship with chlorophyll a concentration in the Three Gorges Dam water; （4） piece- wise function can express the absorption coefficient characteristics of CDOM. The absorption spectrum below 500nm decreases power exponentially from short to long wavelength, and the precision of the fitting R2approaches to 1; the absorption spectrum between 501 and 700nm fits well using polynomial relationship, and the precision R2 is above 95%. 三峡坝区 吸收系数 颗粒物 浮游植物 CDOM Three Gorges Dam absorption coefficient particle matter phytoplankton colored dissolved organic matter （CDOM） TP79 国家科技部科研院所社会公益研究专项（编号:2004DIB3J107）;地理空间信息工程国家测绘局重点实验室经费资助项目（编号:A1714）;中国科学院遥感应用研究所北京师范大学遥感科学国家重点实验室开放研究基金~~ 2021-06-09 2 14