Research Abstracts Online
January 2009 - March 2010
University of Minnesota Duluth
Swenson College of Science and Engineering
Department of Geological Sciences
PI: Karen B. Gran
Co-PI: Lesley A. Perg
An Integrated Sediment Budget for the Le Sueur River Basin, Minnesota
These researchers are developing an integrated sediment budget for the Le Sueur River basin in the Minnesota River watershed. The ultimate goal of this research is to support efforts currently underway by the Minnesota Pollution Control Agency to develop Total Maximum Daily Load allocations for reaches along the Minnesota River, tributary watersheds, and Lake Pepin. Supercomputing resources are used to store large spatial datasets used in the development and execution of the sediment routing model and facilitate data sharing between researchers.
The sediment budget will have several key elements. The group will create a complete budget, including detailed measurements of primary source contributors, movement in and out of storage, and sediment fluxes through the basin. The budget will specifically incorporate spatial scale, modeling watersheds from the scale of first-order basins up to the entire Le Sueur River basin (1,112 mi2). The budget will be based on two parallel approaches: a cosmogenic and fallout radionuclide budget to apportion sediment by sources, and a physical sediment budget utilizing in-field measurements, sediment gauging stations, and air photo analyses to determine sediment flux from the uplands through the watershed, including flux into and out of storage. Radionucleotide tracers provide an estimate of the proportional contribution from different sources and land uses, integrated over a large area, which is crucial for examining non-point source pollutants. The physical budget provides information on location and rates of sediment erosion and supply, allowing targeting of the most impaired areas. The two approaches apply different principles and methods and provide independent corroboration. The sediment budget will be linked to a network routing model, routing sand and fines through the basin.
Luam Azmera, Department of Civil and Environmental Engineering, Florida International University, Miami, Florida
Patrick Belmont, Research Associate
Stephanie Day, Graduate Student
Andrea Johnson, Graduate Student
Carrie Jennings, Adjunct Faculty Collaborator
J. Wesley Lauer, Department of Civil Engineering, Seattle University, Seattle, Washington