The object of this study was to use remotely sensed LANDSAT Thematic Mapper data

combined with the concurrent in situ water quality data

for the assessment and mapping of water pollution level in the area of Suzhou

.Jiangsu Province. The water quality parameters of interest included: （1） Dissolved oxygen （DO）; （2） Biochemical oxygen demand （BOD）; （3） Chemical oxygen demand （COD）; and （4） Organic pollution index A. Based on the statistical analysis of the relationship between TM digital values and the water quality parameters of 9 sampling sites on the Southern Grand Canal

a series of regression models were developed and examined for validity. The most effective model was chosen and extended to the entire study area to map the water quality with signature from the 3 Thematic Mapper visible bands. The spatial distribution of water quality information in this study area was color-coded via digital image processing techniques and successfully verified by the local environmental monitoring station.