SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport Active
SPARROW (SPAtially Referenced Regression On Watershed attributes)
Models and interative mappers to improve understanding environmental processes
SPARROW Mappers
Modeling streamflow, nitrogen, phosphorus, and suspended sediments in streams across five regions of the United States
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 contaminant transport.
Featured: Projecting future flow in Southwest streams
Streamflow in the Southwestern U.S. is projected to decrease by as much as 36–80% by the end of this century, reports a new study by the U.S. Geological Survey. These decreases could challenge our ability to meet future water demand in this region.
Integration of monitoring and modeling is critical to our future understanding and management of the Nation’s water quality. Monitoring is the direct observation, often over time, of water-quality properties and characteristics, and models are tools for interpreting these observations.
SPARROW models are used to estimate long-term average values of water characteristics, such as the amount of a contaminant that is delivered downstream, based on existing monitoring data, location and strength of contaminant sources, and characteristics of the landscape.
SPARROW models can help managers:
- Determine options for reducing loads of contaminants
- Design strategies for protection or to meet regulatory requirements
- Predict changes in water quality that might result from management actions
- Identify gaps and priorities in monitoring network design
SPARROW Mappers
SPARROW mappers are interactive tools that allow the user to explore river nutrient loads and yields and the importance of different sources of contaminants in a particular river basin.
Data can be visualized using maps and interactive graphs and tables, and rankings can be shown by catchment, watershed, and state. Modeling results can be exported as an Excel spreadsheet, CSV file, or a geospatial dataset.
New mappers, representing circa 2012 source inputs, are available for 5 regions of the conterminous United States. The Mappers replace the SPARROW Decision Support System (Booth and others, 2011).
Nutrients and the Nation’s Estuaries
Access maps of watershed nutrients flowing to the Nation’s estuaries and download data tables of nutrient sources and loads. Compare nutrient sources and watersheds that contribute elevated nutrient loads to downstream receiving waters, such as the Southeast Atlantic and Gulf of Mexico, inland and coastal waters of the Northeast, the Upper Mississippi and Great Lakes, Puget Sound and the Northwest coast, and the California coast.
National Models
SPARROW models are unique in that they retain the spatial detail of underlying data sets while extending over areas as large as the conterminous United States. This allows the simultaneous assessment of water-quality conditions in many water bodies. National SPARROW models have been developed for a number of water-quality constituents including nutrients and total dissolved solids.
Regional Models
SPARROW models are flexible—they can be applied to any region where there are specific needs for water-quality information and where data to support modeling are abundant. Five new regional models of streamflow, total nitrogen, total phosphorus and suspended sediment have been developed for the conterminous United States. Other regional models have been developed previously for the Chesapeake Bay, Mississippi River and the Great Lakes watersheds.
International Models
SPARROW models can be applied in any part of the world where sufficient data are available to support model development. Examples include models developed for New Zealand to identify the primary sources of nutrients to streams (Alexander and others, 2002), and a joint U.S.-Canadian effort to build nutrient models for the entire Great Lakes watershed, to better understand nutrient loading to the lakes (Robertson and others, 2019).
Applications of SPARROW models
Once built and calibrated, SPARROW models can be applied in a variety of ways to better understand the environmental factors affecting water-quality conditions in streams.
- SPARROW models were applied at the national scale to estimate natural background levels of nutrients to help guide the potential development of nutrient criteria in streams.
- A model developed for the upper Midwest was used to identify the benefits of management practices designed to limit the amount of agricultural nutrients reaching streams (Garcia and others, 2016).
- A Chesapeake Bay SPARROW model was used to identify those areas that export nitrogen to streams with the greatest efficiency (Ator and Garcia, 2016).
- A SPARROW model was used to simulate impacts of climate change on phosphorus load to Lake Michigan (Robertson and others, 2016).
Research using SPARROW models
SPARROW models can be used as tools in research to better understand the environmental processes that affect water-quality conditions. A SPARROW model for the Mississippi drainage was used to evaluate the role of stream size on denitrification and attenuation of nitrogen levels with transport downstream. Previous studies based on a limited number of sites had hypothesized that the rate of denitrification was significantly greater in smaller streams due to greater sediment contact. This was confirmed by the SPARROW model for which the results were consistent with the other studies, but based on a much larger area and many more measurement locations (Alexander and others, 2000).
Databases
The national data bases used in the SPARROW models have value in themselves and can be used for other scientific evaluations. Attributes, such as point sources discharges, agricultural fertilizer / manure nutrients, atmospheric deposition, climate, geology / soils, land cover, hydrologic characteristics and physical characteristics, are available for all catchments in the RF1 and NHDPlus digital stream networks.
Stream network datasets and watershed attribute data
- The EPA RF1 data set (with attributes) is defined at the 1:500K scale and has stream catchments that are on average 130 km2.
- The NHDPlus data set (with attributes Version 1.1 and Version 2.1) is defined at the 1:100K scale and has stream catchments that are on average 3 km2.
Descriptions of these data sets and how they are used in SPARROW models can be found in Preston and others (2011).
What’s New …
- RSPARROW, now available on the USGS GitLab repository, provides the first open-source version of the USGS SPARROW water-quality model, with new features that improve the utility of the model for conducting studies of contaminants in surface waters and informing water resource management decisions. RSPARROW extends the capabilities of the current proprietary SAS SPARROW version and streamlines user and R developer access to SPARROW modelling technology.
- Although SPARROW models are typically based on a single time period, dynamic versions of SPARROW models are being developed to take advantage of new data sets. Dynamic SPARROW models will account for temporary storage of contaminants and to simulate seasonal variations. They also will allow simulation of contaminant loads through time to estimate the time needed for management actions on the land to affect loads in streams.
Everything you need to know about SPARROW
The links below lead to publications related to SPARROW, including documentation and applications.
Differences in phosphorus and nitrogen delivery to the Gulf of Mexico from the Mississippi River Basin
Dissolved solids in basin-fill aquifers and streams in the southwestern United States
Dominance of organic nitrogen from headwater streams to large rivers across the conterminous United States
The role of headwater streams in downstream water quality
Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation
Trends in the nutrient enrichment of U.S. rivers during the late 20th century and their relation to changes in probable stream trophic conditions
Estimation of nutrient sources and transport for New Zealand using the hybrid mechanistic-statistical model SPARROW
Estimation of Total Nitrogen and Phosphorus in New England Streams Using Spatially Referenced Regression Models
Digital data used to relate nutrient inputs to water quality in the Chesapeake Bay watershed, version 3.0
Estimates of diffuse phosphorus sources in surface waters of the United States using a spatially referenced watershed model
Natural background concentrations of nutrients in streams and rivers of the conterminous United States
A hydrologic network supporting spatially referenced regression modeling in the Chesapeake Bay watershed
SPARROW Modeling Program
SPARROW is a popular watershed modeling technique, distributed by the USGS, that estimates 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.
- Overview
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 contaminant transport.
Featured: Projecting future flow in Southwest streamsStreamflow in the Southwestern U.S. is projected to decrease by as much as 36–80% by the end of this century, reports a new study by the U.S. Geological Survey. These decreases could challenge our ability to meet future water demand in this region.
Integration of monitoring and modeling is critical to our future understanding and management of the Nation’s water quality. Monitoring is the direct observation, often over time, of water-quality properties and characteristics, and models are tools for interpreting these observations.
SPARROW models are used to estimate long-term average values of water characteristics, such as the amount of a contaminant that is delivered downstream, based on existing monitoring data, location and strength of contaminant sources, and characteristics of the landscape.
SPARROW models can help managers:- Determine options for reducing loads of contaminants
- Design strategies for protection or to meet regulatory requirements
- Predict changes in water quality that might result from management actions
- Identify gaps and priorities in monitoring network design
SPARROW Mappers
SPARROW mappers are interactive tools that allow the user to explore river nutrient loads and yields and the importance of different sources of contaminants in a particular river basin.
Data can be visualized using maps and interactive graphs and tables, and rankings can be shown by catchment, watershed, and state. Modeling results can be exported as an Excel spreadsheet, CSV file, or a geospatial dataset.
New mappers, representing circa 2012 source inputs, are available for 5 regions of the conterminous United States. The Mappers replace the SPARROW Decision Support System (Booth and others, 2011).
Nutrients and the Nation’s Estuaries
Access maps of watershed nutrients flowing to the Nation’s estuaries and download data tables of nutrient sources and loads. Compare nutrient sources and watersheds that contribute elevated nutrient loads to downstream receiving waters, such as the Southeast Atlantic and Gulf of Mexico, inland and coastal waters of the Northeast, the Upper Mississippi and Great Lakes, Puget Sound and the Northwest coast, and the California coast.
National Models
SPARROW models are unique in that they retain the spatial detail of underlying data sets while extending over areas as large as the conterminous United States. This allows the simultaneous assessment of water-quality conditions in many water bodies. National SPARROW models have been developed for a number of water-quality constituents including nutrients and total dissolved solids.
Regional Models
SPARROW models are flexible—they can be applied to any region where there are specific needs for water-quality information and where data to support modeling are abundant. Five new regional models of streamflow, total nitrogen, total phosphorus and suspended sediment have been developed for the conterminous United States. Other regional models have been developed previously for the Chesapeake Bay, Mississippi River and the Great Lakes watersheds.
International Models
SPARROW models can be applied in any part of the world where sufficient data are available to support model development. Examples include models developed for New Zealand to identify the primary sources of nutrients to streams (Alexander and others, 2002), and a joint U.S.-Canadian effort to build nutrient models for the entire Great Lakes watershed, to better understand nutrient loading to the lakes (Robertson and others, 2019).
Applications of SPARROW models
Once built and calibrated, SPARROW models can be applied in a variety of ways to better understand the environmental factors affecting water-quality conditions in streams.
- SPARROW models were applied at the national scale to estimate natural background levels of nutrients to help guide the potential development of nutrient criteria in streams.
- A model developed for the upper Midwest was used to identify the benefits of management practices designed to limit the amount of agricultural nutrients reaching streams (Garcia and others, 2016).
- A Chesapeake Bay SPARROW model was used to identify those areas that export nitrogen to streams with the greatest efficiency (Ator and Garcia, 2016).
- A SPARROW model was used to simulate impacts of climate change on phosphorus load to Lake Michigan (Robertson and others, 2016).
Research using SPARROW models
SPARROW models can be used as tools in research to better understand the environmental processes that affect water-quality conditions. A SPARROW model for the Mississippi drainage was used to evaluate the role of stream size on denitrification and attenuation of nitrogen levels with transport downstream. Previous studies based on a limited number of sites had hypothesized that the rate of denitrification was significantly greater in smaller streams due to greater sediment contact. This was confirmed by the SPARROW model for which the results were consistent with the other studies, but based on a much larger area and many more measurement locations (Alexander and others, 2000).
Databases
The national data bases used in the SPARROW models have value in themselves and can be used for other scientific evaluations. Attributes, such as point sources discharges, agricultural fertilizer / manure nutrients, atmospheric deposition, climate, geology / soils, land cover, hydrologic characteristics and physical characteristics, are available for all catchments in the RF1 and NHDPlus digital stream networks.
Stream network datasets and watershed attribute data
- The EPA RF1 data set (with attributes) is defined at the 1:500K scale and has stream catchments that are on average 130 km2.
- The NHDPlus data set (with attributes Version 1.1 and Version 2.1) is defined at the 1:100K scale and has stream catchments that are on average 3 km2.
Descriptions of these data sets and how they are used in SPARROW models can be found in Preston and others (2011).
What’s New …
- RSPARROW, now available on the USGS GitLab repository, provides the first open-source version of the USGS SPARROW water-quality model, with new features that improve the utility of the model for conducting studies of contaminants in surface waters and informing water resource management decisions. RSPARROW extends the capabilities of the current proprietary SAS SPARROW version and streamlines user and R developer access to SPARROW modelling technology.
- Although SPARROW models are typically based on a single time period, dynamic versions of SPARROW models are being developed to take advantage of new data sets. Dynamic SPARROW models will account for temporary storage of contaminants and to simulate seasonal variations. They also will allow simulation of contaminant loads through time to estimate the time needed for management actions on the land to affect loads in streams.
- Science
Everything you need to know about SPARROW
What is SPARROW? SPARROW (SPAtially Referenced Regression On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds such as contaminant sources and environmental factors that affect rates of delivery to streams and in-stream processing. The core of the model consists of a nonlinear... - Data
- Multimedia
- Publications
The links below lead to publications related to SPARROW, including documentation and applications.
Filter Total Items: 64Differences in phosphorus and nitrogen delivery to the Gulf of Mexico from the Mississippi River Basin
Seasonal hypoxia in the northern Gulf of Mexico has been linked to increased nitrogen fluxes from the Mississippi and Atchafalaya River Basins, though recent evidence shows that phosphorus also influences productivity in the Gulf. We developed a spatially explicit and structurally detailed SPARROW water-quality model that reveals important differences in the sources and transport processes that coAuthorsR. B. Alexander, R. A. Smith, G. E. Schwarz, E. W. Boyer, J.V. Nolan, J. W. BrakebillDissolved solids in basin-fill aquifers and streams in the southwestern United States
The U.S. Geological Survey National Water-Quality Assessment Program performed a regional study in the Southwestern United States (Southwest) to describe the status and trends of dissolved solids in basin-fill aquifers and streams and to determine the natural and human factors that affect dissolved solids. Basin-fill aquifers, which include the Rio Grande aquifer system, Basin and Range basin-fillAuthorsDavid W. Anning, Nancy J. Bauch, Steven J. Gerner, Marilyn E. Flynn, Scott N. Hamlin, Stephanie J. Moore, Donald H. Schaefer, Scott K. Anderholm, Lawrence E. SpanglerDominance of organic nitrogen from headwater streams to large rivers across the conterminous United States
The frequency and magnitude of hypoxic areas in coastal waterbodies are increasing across the globe, partially in response to the increase in nitrogen delivery from the landscape (Diaz, 2001; Rabalais et al., 2002). Although studies of annual total nitrogen and nitrate yields have greatly improved understanding of the contaminant sources that contribute to riverine nitrogen loads (Alexander et al.AuthorsD. Scott, J. Harvey, R. Alexander, G. SchwarzThe role of headwater streams in downstream water quality
Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality model to iAuthorsR. B. Alexander, E. W. Boyer, R. A. Smith, G. E. Schwarz, R. B. MooreSection 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation
SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds containing the stations. The core of the model consists of a nonlinear regression equation describing the non-conservative transport of contaminants from point and diffuse sources on lanAuthorsGregory Schwarz, Anne B. Hoos, R. B. Alexander, R. A. SmithTrends in the nutrient enrichment of U.S. rivers during the late 20th century and their relation to changes in probable stream trophic conditions
We estimated trends in concentrations of total phosphorus (TP) and total nitrogen (TN) and the related change in the probabilities of trophic conditions from 1975 to 1994 at 250 nationally representative riverine monitoring locations in the U.S. with drainage areas larger than about 1,000 km2. Statistically significant (p < 0.05) declines were detected in TP and TN concentrations at 44% and 37% ofAuthorsR. B. Alexander, R. A. SmithEstimation of nutrient sources and transport for New Zealand using the hybrid mechanistic-statistical model SPARROW
The hybrid mechanistic-statistical catchment model SPARROW was applied to predict the mean annual load of nitrogen and phosphorus in streams throughout New Zealand (270,000 km2). The loads from land areas, point sources, and erosion are routed through the drainage network (576,300 reaches) with first-order stream decay and attenuation in lakes and reservoirs. Model parameters were determined by caAuthorsA.H. Elliot, R. B. Alexander, G. E. Schwarz, Ude Shankar, J.P.S. Sukias, Graham B. McBrideEstimation of Total Nitrogen and Phosphorus in New England Streams Using Spatially Referenced Regression Models
The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA) and the New England Interstate Water Pollution Control Commission (NEIWPCC), has developed a water-quality model, called SPARROW (Spatially Referenced Regressions on Watershed Attributes), to assist in regional total maximum daily load (TMDL) and nutrient-criteria activities in New England. SPARAuthorsRichard Bridge Moore, Craig M. Johnston, Keith W. Robinson, Jeffrey R. DeaconDigital data used to relate nutrient inputs to water quality in the Chesapeake Bay watershed, version 3.0
Chesapeake Bay restoration efforts are focused on improving water quality, living resources, and ecological habitats by 2010. One aspect of the water-quality restoration is the refinement of strategies designed to implement nutrient-reduction practices within the Bay watershed. These strategies are being refined and implemented by resource managers of the Chesapeake Bay Program (CBP), a partnershiAuthorsJohn W. Brakebill, Stephen D. PrestonEstimates of diffuse phosphorus sources in surface waters of the United States using a spatially referenced watershed model
The statistical watershed model SPARROW (SPAtially Referenced Regression On Watershed attributes) was used to estimate the sources and transport of total phosphorus (TP) in surface waters of the United States. We calibrated the model using stream measurements of TP from 336 watersheds of mixed land use and spatial data on topography, soils, stream hydrography, and land use (agriculture, forest, shAuthorsR. B. Alexander, R. A. Smith, G. E. SchwarzNatural background concentrations of nutrients in streams and rivers of the conterminous United States
Determining natural background concentrations of nutrients in watersheds in the developed world has been hampered by a lack of pristine sampling sites covering a range of climatic conditions and basin sizes. Using data from 63 minimally impacted U.S. Geological Survey reference basins, we developed empirical models of the background yield of total nitrogen (TN) and total phosphorus (TP) from smallAuthorsR. A. Smith, R. B. Alexander, G. E. SchwarzA hydrologic network supporting spatially referenced regression modeling in the Chesapeake Bay watershed
The U.S. Geological Survey has developed a methodology for statistically relating nutrient sources and land-surface characteristics to nutrient loads of streams. The methodology is referred to as SPAtially Referenced Regressions On Watershed attributes (SPARROW), and relates measured stream nutrient loads to nutrient sources using nonlinear statistical regression models. A spatially detailed digitAuthorsJ. W. Brakebill, S. D. Preston - Web Tools
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SPARROW Modeling Program
SPARROW is a popular watershed modeling technique, distributed by the USGS, that estimates 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.
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