SPARROW models used to understand nutrient sources in the Mississippi/Atchafalaya River Basin

Journal of Environmental Quality
By:  and 



Nitrogen (N) and phosphorus (P) loading from the Mississippi/Atchafalaya River Basin (MARB) has been linked to hypoxia in the Gulf of Mexico. To describe where and from what sources those loads originate, SPAtially Referenced Regression On Watershed attributes (SPARROW) models were constructed for the MARB using geospatial datasets for 2002, including inputs from wastewater treatment plants (WWTPs), and calibration sites throughout the MARB. Previous studies found that highest N and P yields were from the north-central part of the MARB (Corn Belt). Based on the MARB SPARROW models, highest N yields were still from the Corn Belt but centered over Iowa and Indiana, and highest P yields were widely distributed throughout the center of the MARB. Similar to that found in other studies, agricultural inputs were found to be the largest N and P sources throughout most of the MARB: farm fertilizers were the largest N source, whereas farm fertilizers, manure, and urban inputs were dominant P sources. The MARB models enable individual N and P sources to be defined at scales ranging from SPARROW catchments (∼50 km2) to the entire area of the MARB. Inputs of P from WWTPs and urban areas were more important than found in most other studies. Information from this study will help to reduce nutrient loading from the MARB by providing managers with a description of where each of the sources of N and P are most important, thus providing a basis for prioritizing management actions and ultimately reducing the extent of Gulf hypoxia.

Study Area

Publication type Article
Publication Subtype Journal Article
Title SPARROW models used to understand nutrient sources in the Mississippi/Atchafalaya River Basin
Series title Journal of Environmental Quality
DOI 10.2134/jeq2013.02.0066
Volume 42
Issue 5
Year Published 2013
Language English
Publisher American Society of Agronomy
Contributing office(s) Wisconsin Water Science Center
Description 19 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Journal of Environmental Quality
First page 1422
Last page 1440
Country United States
Other Geospatial Mississippi/atchafalaya River Basin
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