基于光谱特征的三峡坝区水色要素反演

Retrieval of water constituents based on spectrum characters in Three Gorges Dam

基于野外测定的水质参数,通过研究三峡坝区水体中水色要素浓度与反射率之间的关系,选择反演叶绿素、悬浮物、溶解性有机物的最佳波段,建立了反演水色要素浓度的遥感定量模型。研究表明,在波段比值的基础上进行幂次修正的波段组合反射率与SS浓度相关性较好(R2=0.76),可以用来估算悬浮物浓度;悬浮物浓度影响叶绿素浓度的反演精度,通过在模型中增加一个红绿波段比值指数项的方法能够抑制或削弱悬浮物的影响,提高了叶绿素浓度的反演精度(R2=0.75);DOC反演模型中,绿光波段与红光波段反射率的对数值能较好的估算DOC浓度,且与log(DOC)相关程度最高,决定系数为0.85,反演精度较高。

Based on water quality parameters measured in fields and the relation between water constituents consistence and irradiance reflectance in Three Gorges Dam, we choose the best bands that can retrieve Chlorophyll(Chl),Suspended Solids(SS) and Dissolved Organic Carbon(DOC) and establish the Remote Sensing quality model of water constituents consistence retrieval.The results show that the correlation between SS consistence and irradiance reflectance of bands combination that have exponential ameliorations based on the ratio of bands is better(R2=0.76),which can estimate SS consistence.SS consistence influences the retrieval of Chl, adding a band ratio exponent of red and blue in retrieval model can weaken the infection of SS, which increases the precision of Chl retrieval effectively(R2=0.75);in DOC retrieval model, the logarithm of band red and band green can estimate DOC consistence better and has better precision, the correlation between it and log(DOC) is better,up to 0.85.