Measuring Suspended-Sediment Concentration and Turbidity in the Middle Mississippi and Lower Missouri Rivers Using Landsat Data

The Middle Mississippi River (MMR) and lower Missouri River (MOR) provide critical navigation waterways, ecological habitat, and flood conveyance. They are also directly linked to processes affecting geomorphic and ecological conditions in the lower MR and Delta. For this study, a method was developed to measure suspended-sediment concentration (SSC) and turbidity along the MMR and the lower MOR using Landsat imagery. Data from nine United States Geological Survey water-quality monitoring stations were used to create a model-development dataset and a model-validation dataset. Concurrent gaging data were identified for available Landsat images to generate the datasets. Surface-reflectance filters were developed to eliminate images with cirrus cloud coverage or vessel traffic. Using the filtered model-development dataset, unique reflectance-SSC and reflectance-turbidity models were developed for three Landsat sensors: Landsat 8 Operational Land Imager, Landsat 7 Enhanced Thematic Mapper Plus, and Landsat 4-5 Thematic Mapper. Coefficient of determination values for the models ranged from 0.72 to 0.88 for the model-development dataset. The model-validation dataset was used to evaluate the performance of the models and had coefficient of determination values ranging from 0.62 to 0.79.