基于MODIS资料的太湖蓝藻浓度监测

Monitoring the concentration of cyanobacteria in Taihu Lake based on MODIS data

为反演太湖蓝藻浓度分布,可以根据MODIS卫星资料绘制1、2、6三通道合成图,但该方法只能定性分析太湖蓝藻的分布区域和分布范围,难以定量分析各蓝藻分布区的蓝藻浓度。为了克服这一局限性,本文主要采用MODIS卫星资料中第2、第1波段的反射率比值和第6波段反射率值,运用二维光谱空间函数分割方法,反演出太湖区域蓝藻浓度的分布情况,定量确定各蓝藻分布区域的蓝藻浓度大小。在此基础上再加上实测数据资料的支持,就可建立蓝藻预警系统,对蓝藻的爆发与防治起到未雨绸缪的作用。

The color composition of wave bands based on the MODIS data is often used to extract the information of cyanobacteria bloom in Tai Lake.Although this method could define the macroscopic distribution region of cyanobacteria bloom,the relative concentration of cyanobacteria bloom remains unknown.To eliminate this restriction,in this paper the ratio between band 2 and band 1,the reflectance of band 6 are used to get the reflectance extent of cyanobacteria of different concentration levels,through which we can obtain more detailed information of the relative content of the cyanobacteria bloom.With the observation data added up,a real time monitoring system in Tai Lake is developed to detect the cyanobacteria bloom effectively,which will play an important role in the prevention and control of cyanobacteria bloom.