| Human activities impact the quality of water in lakes and bays in many ways. Eutrophication, one of the most pervasive problems that had been of concerned in both Michigan and Thailand, primarily caused by excessive nutrient export in runoff from urban and agricultural landscapes,{09}Traditional water quality monitoring techniques are costly and time-consuming, thereby often resulting in only a sporadic sampling over time and space. Satellite sensors, such as Landsat TM and ETM+, has the potential to enhance the environmental resource management as it was found to well correlated with Secchi Disc Transparency (SDT). The purpose of this study is to test the accuracy and the applicability of the satellite-based water clarity/trophic condition monitoring in Michigan lakes and the Bight of Bangkok, Thailand.; The results of this study showed that the accuracy of using satellite data for water clarity/trophic status measurement was quite high ( r2 values 0.57--0.70; p < 0.001) in Michigan and even higher (r2 > 0.83; p < 0.001) in Bangkok Bight, Thailand. These accuracies were achieved by converting digital numbers to radiance before correlating to water clarity. Therefore, this method can be used with both Landsat-5 TM and Landsat-7 ETM+ allowing a finer temporal scale monitoring. An advantage of this study is to provide a potentially water monitoring on a regional scale within a single day at low cost. |
