基于ETM+影像的千岛湖叶绿素a浓度卫星遥感反演研究

Inversion of Chlorophyll-a Concentration Based on Satellite Remote Sensing in Qiandao Lake

以千岛湖为研究对象,利用Landsat 7 ETM+遥感影像与野外实测数据,建立叶绿素a浓度的遥感定量反演模型。将叶绿素a浓度与波段反射率组合进行Pearson相关性分析,选择(B4+B2)/B3波段组合构建叶绿素a反演模型,并得到千岛湖叶绿素a浓度的时空分布。结果表明:(1)2007年千岛湖叶绿素a浓度低于4μg/L的水体面积占水体总面积达到99%以上,整体水质优良;(2)千岛湖叶绿素a浓度随季节变化特征明显,夏季容易出现局地高值,秋季平均浓度整体升高;(3)通过反演不同时期的叶绿素a浓度分布,可以刻画出千岛湖藻类的消长过程,从空间上发现易爆发富营养化的区域。该反演模型能较为精确地估算千岛湖的叶绿素a浓度,对今后水体富营养化的监测和预警具有重要意义。

Taking Qiandao Lake as the research object,the remote sensing quantitative retrieval model of chlorophyll a concentration was established using the Landsat 7 ETM + remote sensing image and field measurement data. Make Pearson correlation analysis of chlorophyll concentration and spectral reflectance combination,select( B4 + B2) / B3 band combination construction of chlorophyll-a retrieval model,and obtain chlorophyll-a concentration of temporal and spatial distribution. Results show that:( 1) in 2007 from Qiandao Lake chlorophyll a concentration below 4 ug / L water area accounted for the total water ara reaches above 99%,the overall good water quality;( 2) chlorophyll-a concentration with characteristics of the seasonal change obviously,the summer to local high value,autumn average concentration of whole body increased.;( 3) by inversion of the distribution of chlorophyll a concentration in different periods,the growth and Octline of the algae in Qiandao Lake can be described. This inversion model can estimate the concentration of chlorophyll a in Qiandao Lake,which is of great significance for the monitoring and early warning of water eutrophication in the future.