Mary Megison - Ecological Modeling
University of South Carolina, Columbia
Erosion Potential Based on Stream Characteristics:
Integrating Fluvial Geomorphology and Stream Ecology
Hillslope models (ie. those focusing outside the channel, on the landscape) are commonly used to predict sediment concentrations and nutrient loads in streams. However, these do not incorporate fluvial processes, such as bank erosion and deposition. Integrating stream characteristics should better predict sediment concentrations. This study uses Digital Elevation Models (DEMs) with 2 m resolution to identify and analyze stream characteristics in headwater catchments. Light Detection and Ranging (LiDAR) was able to capture the full extent of these headwater components of the stream and were analyzed in ArcGIS 9.2. Here the longitudinal profile data were analyzed; total stream length, total drainage area, drainage density, main stem stream length, main stem slope, and stream power were related to observed sediment concentrations (mg/L) in thirteen sub-watersheds within the Chesapeake Bay Watershed. In the final model, drainage area, total stream length, and main stem slope accounted for 80.1% of the observed variance in sediment concentrations. This preliminary analysis suggests that differences occur among physiographic provinces, yet has still successfully used stream characteristics as a source driving sediment concentrations. This study has potential for further implications in relation to ecological habitats, water quality, and management practices interested in total maximum daily loads (TMDL).
Funding was provided by Smithsonian Institution Women’s Committee