Assessing the potential of Medium-Resolution Imaging Spectrometer (MERIS) and Moderate-Resolution Imaging Spectroradiometer (MODIS) data for monitoring total suspended matter in small and intermediate sized lakes and reservoirs

Satellite remote sensing has been used extensively for many years to monitor the open oceans and coastal waters. These methods have been extended more recently to the study of inland waters. In this study we consider the potential application of data from two ocean color sensors, Moderate-Resolution Imaging Spectroradiometer (MODIS) and Medium-Resolution Imaging Spectrometer (MERIS), for monitoring the levels of suspended solids in small and intermediate sized lakes and reservoirs. We measured total suspended matter (TSM) in four southwestern United States lakes, Roosevelt Lake, Saguaro Lake, Bartlett Lake, and Lake Pleasant, and compared these field data with images obtained from these medium resolution satellite sensors. Our regression analysis of the complete data set identified a linear relationship between the field TSM values and both MODIS 250 m data (r² = 0.461) and MERIS 290 m data (r² = 0.521). This relationship improved substantially when data from the smallest lake in the study (Saguaro Lake) were excluded from the analysis (r² = 0.819 and r² = 0.888, respectively). The resultant linear models produced estimates with a root-mean-square error (RMSE) ranging from 3.14 mg/L (MODIS) and 2.04 mg/L (MERIS) for all four lakes combined, improving to 1.32 mg/L (MODIS) and 0.47 mg/L (MERIS) for a lake-specific regression. These results suggest that these satellite sensors have the potential to effectively monitor TSM in lakes and reservoirs, although a minimum practical lake size does appear to exist.