A study was done to examine the possibility of acquiring water quality information on the lakes of Kanagawa Prefecture by satellite remote sensing. Water temperature and transparency, suspended solids, and chlorophyll-a concentration were examined by statistical techniques using actual measured data for lakes and Thematic Mapper (TM) data from the artificial satellite Landsat 5. Two correlation analyses were done: one among the water quality parameters, and the other between the water quality parameters and the TM data. The correlation between the TM data and each parameter of the surface water quality was high except chlorophyll-a. Therefore, the TM data allowed accurate estimation of water quality except for chlorophyll-a concentration. Data showing large differences in water quality from each lake were used to derive a linear regression expression for estimating water quality with TM data. Using this expression, estimated distribution images of water quality were made, except for chlorophyll-a concentration. The data for chlorophyll-a concentration, which is an index of water blooms showing deterioration of the lake environment, were separated into low and high, allowing a linear regression expression to be derived respectively from these data, and construction of chlorophyll-a estimation images. Our findings suggest that water quality estimation from artificial satellite data may be reliable, particularly with regard to water temperature and transparency, suspended solids and chlorophyll-a concentration.
