SPARROW models for the Great Lakes, Ohio River, Upper Mississippi River, and Red River Basins predict long-term mean annual loads, yields, concentrations, and source contributions of water, nitrogen, phosphorus, and sediment throughout the Midwest.
SPARROW (SPAtially Referenced Regression On Watershed attributes) models track the transport of water, nutrients (particularly nitrogen and phosphorus), and sediment from local inland watersheds to regional, coastal waters by explaining spatial patterns in
stream water-quality conditions in relation to human activities and natural processes.
Ongoing 2012 Midwest SPARROW Models

As part of the National Water-Quality Program, the capabilities of SPARROW were expanded to include streamflow and suspended sediment. Updated SPARROW models were developed using nutrient input data from management practices similar to 2012. These models were developed using smaller catchments (average of 2 square kilometer catchments) to enable improved spatial descriptions of nutrient and sediment sources. The models were calibrated using streamflow and total phosphorus, total nitrogen, and suspended sediment loads from sites throughout the Midwest. These four models are described in U.S. Geological Survey Scientific Investigation Report 2019-511.
SPARROW simulated incremental nitrogen yields from the Midwest part of the United States. Results from all four models can be obtained with a SPARROW Mapper (link the figure and Mapper to: https://sparrow.wim.usgs.gov/sparrow-midwest-2012/ ).
2002 MRB3 SPARROW Models
The Great Lakes, Ohio, Upper Mississippi and Red River Basins (MRB3; Upper Midwest) SPARROW models were based on 2002 nutrient-input data and included watersheds that deliver nitrogen and phosphorus to the Great Lakes (published in the Journal of the American Water Resources Association in 2011) and Upper Mississippi and Ohio River Basins.
The 2002 MRB3 models indicated:
- 2002 U.S. nutrient loadings to Lakes Michigan and Ontario were similar to those in the 1980s, whereas loadings to Lakes Superior, Huron, and Erie had decreased.
- Highest loads were from tributaries with the largest watersheds, but the highest yields were from areas with intense agriculture and large point sources of nutrients.
- Input from agricultural areas was a dominant source of nutrients, contributing 33-44% of the phosphorus and 33-58% of the nitrogen to each of the Great Lakes, except for areas around Superior with little agriculture.
- Point sources were also important in some areas, contributing 14-44% of the phosphorus and 13-34% of the nitrogen to each of the Great Lakes.
- Watersheds around Lake Erie contributed nutrients at the highest rate (similar to intensively farmed areas in the Midwest) because they have the largest nutrient inputs and highest amount delivered downstream, while those around Lake Superior contributed the least nutrients.
- Nutrient deposition in lakes and reservoirs intersecting the tributaries to the Great Lakes was important in reducing nutrient delivery to the lakes.
Read the full press release on the 2002 MRB3 SPARROW model results.
Binational (Canada and U.S.) SPARROW Models
SPARROW models have been developed for the entire binational Great Lakes, Lake of the Woods basin. See the Binational SPARROW modeling page.
Mississippi/Atchafalaya River Basin Models
SPARROW models have been developed for the entire Mississippi/Atchafalaya River Basin. See the Mississippi/Atchafalaya modeling page.
National SPARROW Website
SPARROW models have been developed for many other areas of the U.S. and other countries. See the National SPARROW web page.
Below are other science projects associated with this project.
SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
SPARROW nutrient modeling: Mississippi/Atchafalaya River Basin (MARB)
SPARROW nutrient modeling: Binational (US/Canada) models
Below are publications associated with this project.
Nitrogen and phosphorus sources and delivery from the Mississippi/Atchafalaya River Basin: An update using 2012 SPARROW models
Estimates of long-term mean daily streamflow and annual nutrient and suspended-sediment loads considered for use in regional SPARROW models of the Conterminous United States, 2012 base year
Spatially referenced models of streamflow and nitrogen, phosphorus, and suspended-sediment loads in streams of the midwestern United States
Simulated impacts of climate change on phosphorus loading to Lake Michigan
Spatial variability in nutrient transport by HUC8, state, and subbasin based on Mississippi/Atchafalaya River Basin SPARROW models
Effects of future urban and biofuel crop expansions on the riverine export of phosphorus to the Laurentian Great Lakes
Nutrient inputs to the Laurentian Great Lakes by source and watershed estimated using SPARROW watershed models
Below are data or web applications associated with this project.
2012 SPARROW Models for the Midwest: Total Phosphorus, Total Nitrogen, Suspended Sediment, and Streamflow
2012 SPARROW (SPAtially Referenced Regressions On Watershed attributes) interactive mappers are available for 5 regions of the conterminous U.S. These mappers simulate river streamflow, and nutrient and sediment loads and yields, that would occur under long-term average hydrologic conditions for the time period 1999 through 2014, and source inputs that occurred during or near 2012.
Below are partners associated with this project.
- Overview
SPARROW models for the Great Lakes, Ohio River, Upper Mississippi River, and Red River Basins predict long-term mean annual loads, yields, concentrations, and source contributions of water, nitrogen, phosphorus, and sediment throughout the Midwest.
SPARROW (SPAtially Referenced Regression On Watershed attributes) models track the transport of water, nutrients (particularly nitrogen and phosphorus), and sediment from local inland watersheds to regional, coastal waters by explaining spatial patterns in
stream water-quality conditions in relation to human activities and natural processes.2012 SPARROW Models for the Midwest: Total Phosphorus, Total Nitrogen, Suspended Sediment, and Streamflow Ongoing 2012 Midwest SPARROW Models
Sources/Usage: Public Domain. Visit Media to see details.(a) Total phosphorus delivered to each of the Great Lakes, (b) total phosphorus deliveries to the Great Lakes, subdivided by each contributing source, and (c) total phosphous delivered from the entire MRB3 basin. As part of the National Water-Quality Program, the capabilities of SPARROW were expanded to include streamflow and suspended sediment. Updated SPARROW models were developed using nutrient input data from management practices similar to 2012. These models were developed using smaller catchments (average of 2 square kilometer catchments) to enable improved spatial descriptions of nutrient and sediment sources. The models were calibrated using streamflow and total phosphorus, total nitrogen, and suspended sediment loads from sites throughout the Midwest. These four models are described in U.S. Geological Survey Scientific Investigation Report 2019-511.
SPARROW simulated incremental nitrogen yields from the Midwest part of the United States. Results from all four models can be obtained with a SPARROW Mapper (link the figure and Mapper to: https://sparrow.wim.usgs.gov/sparrow-midwest-2012/ ).
2002 MRB3 SPARROW Models
The Great Lakes, Ohio, Upper Mississippi and Red River Basins (MRB3; Upper Midwest) SPARROW models were based on 2002 nutrient-input data and included watersheds that deliver nitrogen and phosphorus to the Great Lakes (published in the Journal of the American Water Resources Association in 2011) and Upper Mississippi and Ohio River Basins.
The 2002 MRB3 models indicated:- 2002 U.S. nutrient loadings to Lakes Michigan and Ontario were similar to those in the 1980s, whereas loadings to Lakes Superior, Huron, and Erie had decreased.
- Highest loads were from tributaries with the largest watersheds, but the highest yields were from areas with intense agriculture and large point sources of nutrients.
- Input from agricultural areas was a dominant source of nutrients, contributing 33-44% of the phosphorus and 33-58% of the nitrogen to each of the Great Lakes, except for areas around Superior with little agriculture.
- Point sources were also important in some areas, contributing 14-44% of the phosphorus and 13-34% of the nitrogen to each of the Great Lakes.
- Watersheds around Lake Erie contributed nutrients at the highest rate (similar to intensively farmed areas in the Midwest) because they have the largest nutrient inputs and highest amount delivered downstream, while those around Lake Superior contributed the least nutrients.
- Nutrient deposition in lakes and reservoirs intersecting the tributaries to the Great Lakes was important in reducing nutrient delivery to the lakes.
Read the full press release on the 2002 MRB3 SPARROW model results.
Binational (Canada and U.S.) SPARROW Models
SPARROW models have been developed for the entire binational Great Lakes, Lake of the Woods basin. See the Binational SPARROW modeling page.
Mississippi/Atchafalaya River Basin Models
SPARROW models have been developed for the entire Mississippi/Atchafalaya River Basin. See the Mississippi/Atchafalaya modeling page.
National SPARROW Website
SPARROW models have been developed for many other areas of the U.S. and other countries. See the National SPARROW web page.
- Science
Below are other science projects associated with this project.
SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources. Interactive, online SPARROW mapping tools allow for easy access to explore relations between human activities, natural processes, and...SPARROW nutrient modeling: Mississippi/Atchafalaya River Basin (MARB)
SPARROW models for the Mississippi/Atchafalaya River Basin(MARB) predict long-term average loads, concentrations, yields, and source contributions of water, nitrogen, phosphorus, and suspended sediment to the Gulf of Mexico.SPARROW nutrient modeling: Binational (US/Canada) models
SPARROW phosphorus and nitrogen models are being developed for the entire Great Lakes Basin and the Upper Midwest part of the U.S., and the Red and Assiniboine River Basin, as part of a Binational project between the USGS and the International Joint Commission (IJC) and National Research Council (NRC) of Canada. - Publications
Below are publications associated with this project.
Nitrogen and phosphorus sources and delivery from the Mississippi/Atchafalaya River Basin: An update using 2012 SPARROW models
Nitrogen (N) and phosphorus (P) inputs throughout the Mississippi/Atchafalaya River Basin (MARB) have been linked to the Gulf of Mexico hypoxia and water‐quality problems throughout the MARB. To describe N and P loading throughout the MARB, SPAtially Referenced Regression On Watershed attributes (SPARROW) models were previously developed based on nutrient inputs and management similar to 1992 andAuthorsDale M. Robertson, David A. SaadEstimates of long-term mean daily streamflow and annual nutrient and suspended-sediment loads considered for use in regional SPARROW models of the Conterminous United States, 2012 base year
Streamflow, nutrient, and sediment concentration data needed to estimate long-term mean daily streamflow and annual constituent loads were compiled from Federal, State, Tribal, and regional agencies, universities, and nongovernmental organizations. The streamflow and loads are used to develop Spatially Referenced Regressions on Watershed Attributes (SPARROW) models. SPARROW models help describe thAuthorsDavid A. Saad, Gregory E. Schwarz, Denise M. Argue, David W. Anning, Scott A. Ator, Anne B. Hoos, Stephen D. Preston, Dale M. Robertson, Daniel WiseSpatially referenced models of streamflow and nitrogen, phosphorus, and suspended-sediment loads in streams of the midwestern United States
In this report, SPAtially Referenced Regression On Watershed attributes (SPARROW) models developed to describe long-term (2000–14) mean-annual streamflow, total nitrogen (TN), total phosphorus (TP), and suspended-sediment (SS) transport in streams of the Midwestern part of the United States (the Mississippi River, Great Lakes, and Red River of the North Basins) are described. The nutrient and suspAuthorsDale M. Robertson, David A. SaadSimulated impacts of climate change on phosphorus loading to Lake Michigan
Phosphorus (P) loading to the Great Lakes has caused various types of eutrophication problems. Future climatic changes may modify this loading because climatic models project changes in future meteorological conditions, especially for the key hydrologic driver — precipitation. Therefore, the goal of this study is to project how P loading may change from the range of projected climatic changes. ToAuthorsDale M. Robertson, David A. Saad, Daniel E. Christiansen, David J LorenzSpatial variability in nutrient transport by HUC8, state, and subbasin based on Mississippi/Atchafalaya River Basin SPARROW models
Nitrogen (N) and phosphorus (P) loading from the Mississippi/Atchafalaya River Basin (MARB) has been linked to hypoxia in the Gulf of Mexico. With geospatial datasets for 2002, including inputs from wastewater treatment plants (WWTPs), and monitored loads throughout the MARB, SPAtially Referenced Regression On Watershed attributes (SPARROW) watershed models were constructed specifically for the MAAuthorsDale M. Robertson, David A. Saad, Gregory E. SchwarzEffects of future urban and biofuel crop expansions on the riverine export of phosphorus to the Laurentian Great Lakes
Increased phosphorus (P) loadings threaten the health of the world’s largest freshwater resource, the Laurentian Great Lakes (GL). To understand the linkages between land use and P delivery, we coupled two spatially explicit models, the landscape-scale SPARROW P fate and transport watershed model and the Land Transformation Model (LTM) land use change model, to predict future P export from nonpoinAuthorsMeredith B. LaBeau, Dale M. Robertson, Alex S. Mayer, Bryan C. Pijanowski, David A. SaadNutrient inputs to the Laurentian Great Lakes by source and watershed estimated using SPARROW watershed models
Nutrient input to the Laurentian Great Lakes continues to cause problems with eutrophication. To reduce the extent and severity of these problems, target nutrient loads were established and Total Maximum Daily Loads are being developed for many tributaries. Without detailed loading information it is difficult to determine if the targets are being met and how to prioritize rehabilitation efforts. TAuthorsDale M. Robertson, David A. Saad - Web Tools
Below are data or web applications associated with this project.
2012 SPARROW Models for the Midwest: Total Phosphorus, Total Nitrogen, Suspended Sediment, and Streamflow
2012 SPARROW (SPAtially Referenced Regressions On Watershed attributes) interactive mappers are available for 5 regions of the conterminous U.S. These mappers simulate river streamflow, and nutrient and sediment loads and yields, that would occur under long-term average hydrologic conditions for the time period 1999 through 2014, and source inputs that occurred during or near 2012.
- Partners
Below are partners associated with this project.