Using rem ote sensed data and G IS technique to estimate surface chlorophyll-a of Chaohu Lake

The thematic mapper(TM)images from Landsat-V satellite are characterized by a short acquired period(16 days per cycle)，and high spatial and spectral resolution．It is cheap and convenient to establish a dynamic monitoring system for water quality in large lakes by combining TM image data and measured data with a chemical method．In this paper the TM image digitized and GIS technology have been used to acquire digital remote sensing data．At the time the TM image were taken，samples ofchlorophyll-afrom the surface water of Chaohu Lake were colleeted and analyzed．Comparing the TM image digitized data with the measured ehlorophyll-a data，the relationships have been found and quantitative models have been established．Applying the model as supported by a GIS，the map ofchlorophyll-a distribution in the surface of Chaohu Lake has been produced．The average concentration of surface chlorophyll-a of Chaohu Lake is calculated．