| The Chesapeake Bay is the largest estuary in North America, borders six states and is over 64,000 square miles. It is home to more than 3,600 species of plants and animals, and approximately 17 million residents. Water quality and ecological habitat has degraded over time due to anthropogenic processes. The Environmental Protection Agency (EPA) has set Total Maximum Daily Load (TMDL) goals to restore the Bay. Of the pollutants, sediment is of particular concern. This remote sensing study used Visual Data 8.2 and Landsat 7 satellite images to detect and evaluate the spatial distribution of sediment within the water column through the creation of natural and false color composites and image ratios. In the natural color composite, browner shades of suspended sediment appear to represent river input sediment while coastal erosion sediment appears to be in a light green color. In the standard false color composite, green shades of suspended sediment coincide with the river input sediment, while lighter blue and teal shades are concurrent with the coastal erosion sediment. While sediment can be detected using an image ratio, results are not as favorable as using a color composite. The standard false color composite is an improvement over the natural color composite due to the fact that the contrast is enhanced and features such as urbanization and vegetation are more easily discerned. Although all three of the methods evaluated proved useful, the creation of a color composite using three bands was superior and provided the best tool in evaluating sediment sources and distribution patterns. |
