MODIS卫星遥感监测太湖蓝藻的初步研究

APRIMARY STUDY OF BLUE ALGAE BLOOM MONITORING WITH MODIS REMOTELY SENSED DATA IN TAIHU LAKE

依据2007年1～6月MODIS卫星遥感影像反演得到的太湖MODIS卫星表层水温、表层叶绿素浓度分布图,以及真彩色(1,4,3波段)合成图像,监测分析了太湖蓝藻的分布和变化情况。水温、表层叶绿素浓度分布图显示,1～6月,太湖表层水温和叶绿素浓度的分布具有明显的区域性和季节性变化特征,且可以很好的显现藻类的迁移与堆积状况,其分布及变化趋势与实测的太湖蓝藻爆发的强度、地点、分布范围基本一致。MODIS真彩色合成图像直观地反映了湖中藻类的宏观信息,其趋势与叶绿素a浓度的分布极其一致。结果表明,利用MODIS遥感数据探测太湖蓝藻水华的分布状况是可行的,MODIS可用于监测内陆湖泊藻类水华的污染情况。

In this paper, the distribution and variation of algae was monitored and analyzed according to the retrieved surface water temperature （SWT） and chlorophyll-a concentration as well as true colour （1, 4, 3-band） synthetic images of MODIS in Taihu lake from January to June, 2007. The results show that from January to June, there are several regional and seasonal characteristics both of the surface water temperature and chlorophyll-a concentration in the Taihu Lake, which obviously show the transference and accumulation of algae. The distribution and the trend of change are found to be consistent with the factual data about the intensity, location, the scope of the outbreak algae in Taihu Lake. The true colour synthetic images of MODIS can directly reflect the macro-scopical distribution of algae and distribution of algae from the synthetic images are extremely consistent with that of chlorophyll-a concentration. The results indicate that using MODIS remote sensed data to monitor distribution of algae in large scale lake is feasible. This study gained a good experiment in monitoring the number of algae, spatial distribution, which will do good to future study on assessing the severity of the algae bloom and discussing conter-meature to the outbreak of algae.