Estimation of Nutrient and Sediment Loading in the Mississippi River and Great Lakes Basins with Regional SPARROW Models
Project Number: 9KM30 and CRM60
Project Chief: Dale M. Robertson
Other Principal Investigators: Richard Alexander (Virginia), David Saad (Wisconsin), Richard Rebich (Mississippi), and Lori Sprague (Colorado)
Project Topics: Mississippi River and Great Lakes Basins
Cooperators: U.S. Environmental Protection Agency
Period of Project: October 2005 – Continuing
Enlarge map. This project will develop calibrated SPARROW models to estimate nutrient and sediment loading from streams in MARB and Upper Mississippi River/Great Lakes Basin (MRB3) for conditions similar to 1992 and 2002.
Problem
As part of the U.S. Environmental Protection Agency (USEPA) National Water Quality Inventory--1996 Report to Congress, water-quality conditions in 19 percent of the Nation’s rivers and streams were surveyed. Based on the results of the survey, nutrient over enrichment (and accompanying high productivity) and siltation were found to be the two most significant causes of impairment in those waters. Excessive export of nutrients from the Mississippi/Atchafalaya River Basin has also been linked to hypoxia in the Gulf of Mexico. One of the principal causes for the increasing size of the hypoxic zone is believed to be the increasing supply of nitrogen delivered to the Gulf from the Mississippi River Basin.
Objectives
The objectives of this study are to:
- Assemble a database containing nutrient (nitrogen and phosphorus) and suspended sediment concentration data and flow data from the USGS and the major sampling agency(s) for the entire Mississippi-Atchafalya Basins (MARB) and Great Lakes Basin (GLB).
- Estimate nutrient and sediment loading for 1970 to 2007 for sites in MARB and GLB with sufficient data using the USGS load program Fluxmaster. These data will be detrended and used to estimate loads typical for 1992 and 2002.
- Develop calibrated SPARROW models to estimate nutrient and sediment loading from streams in MARB and Upper Mississippi River/Great Lakes Basin (MRB3) for conditions similar to 1992 and 2002.
- Loading throughout the MARB
- 1992 Loading will be based on the 1992 National SPARROW models.
- 2002 Loading will be based on regional models developed just for MARB.
- Loading throughout the Upper Misssissippi/Great Lakes Basin (MRB3)
- 1992 and 2002 Loading will be based on regional models developed just for MRB3.
- Describe the distribution of nutrient and suspended sediment loading and the factors influencing these distributions throughout MARB and MRB3.
- Rank all of the basins based on the relative yields of nutrient and suspended sediment throughout the MARB and MRB3 for 1992 and 2002.
Web Links
Publications and Reports
Smith, R.A., Schwarz, G.E., and Alexander, R.B., 1997, Regional interpretation of water-quality monitoring data, Water Resources Research, 33, 12, 2781-2798.
Smith, R.A., Alexander, R.B., and Schwarz, G.E., 2003, Estimating the natural background concentrations of nutrients in streams and rivers of the conterminous United States, Environ. Sci. Tech., 37, 3039-3047.
Presentations
Robertson, Dale and Richard Alexander. 29 June 2007. SPARROW modeling in the Mississippi and Atchafalaya River Basins (MARB) (SPARROW_MARB_Ranking_1992.pps)
Robertson, Dale M., Saad, D.A., Alexander, R.A., and Schwarz, G.E. 24 July 2008. SPARROW Modeling – with special emphasis on modeling in the Mississippi River Basin and Upper Midwest. Upper Midwest Partnership Meeting. (MWPartnership_SPARROW_July2008.ppt)
Data Files
Ranking of Basins (to be added soon)
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