REMOTE SENSING OF TOTAL SUSPENDED PARTICULATES IN THE WESTERN BASIN OF LAKE ERIE

The riverine influx of total suspended particulates (TSP) into the western basin of Lake Erie is one of the major non-point source pollution problems in the region. Ninety-five percent of Lake Erie's total inflow is transported by the Detroit River from the upper Great Lakes. Other major tributaries in the western basin of Lake Erie include the Huron River, Ottawa River, River Raisin, Maumee River, Toussaint River, and Portage River. We focused on assessing the river runoff into the western basin of Lake Erie because the majority of sediment enters Lake Erie via the western basin. We compared several remote sensing algorithms, generated based on different spectral regions of the dark object subtracted Landsat5 TM and Landsat7 ETM+ satellite data to determine which was most effective at identifying total suspended sediments. Our results indication that a version of the normalized difference water index (NDWI), which retrieves reflected satellite data from visible and shortwave infrared spectral regions of Landsat imagery, worked best as a tool for mapping TSP plumes. This is because suspended sediment is reflective in the visible, while clear water absorbs efficiently in the near infrared part of the electromagnetic spectrum. The NDWI index values were proportional to the concentration of TSP present in the water body. The temporal and spatial distribution patterns of the TSP in surface water were mapped to explore variation in suspended sediment concentration in Lake Erie.