Author(s): James P. Selegean

Linked Author(s):

Keywords: No Keywords

Abstract: Sediment movement through the St. Joseph River Watershed has been subject to significant human modification over the past 200 years. These modifications include logging, development of agricultural land, dam construction, urbanization, river channel alteration, and the construction of harbor works. The firs major dam was constructed in 1850 and 65 large dams now exist in the 12,000 km2watershed. Only 13 % of the watershed now drains directly to the river mouth, and dams form a significant trap for sediment sources from the remaining 87 % of the watershed. A variety of techniques were used to assess the roles of land-use change and dam construction in altering sediment movement through the watershed. Watershed sediment yield and delivery under changing land uses were assessed using the SWAT model. Historic dredging records of the navigable lower river over a 150-year period were evaluated to determine sedimentation rates. A two-dimensional hydrodynamic and sediment transport model (RMA2-SED2D) was used to examine the effects of upstream sediment delivery on the morphodynamics of the harbor and river mouth and to use the dredging data to evaluate the sediment delivery model through establishment of historic harbor sediment trapping rates.

DOI:

Year: 2009