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John Brakebill (Former Employee)

Science and Products

Filter Total Items: 20

CONUS404: The NCAR-USGS 4-km long-term regional hydroclimate reanalysis over the CONUS

A unique, high-resolution, hydroclimate reanalysis, 40-plus-year (October 1979–September 2021), 4 km (named as CONUS404), has been created using the Weather Research and Forecasting Model by dynamically downscaling of the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate dataset (ERA5) over the conterminous United...
Authors
R. M. Rasmussen, F. Chen, C. H. Liu, K. Ikeda, A. Prein, J. Kim, T. Schneider, A. Dai, D. Gochis, A. Dugger, Y. Zhang, A. Jaye, J. Dudhia, C. He, M. Harrold, L. Xue, S. Chen, A. Newman, E. Dougherty, R. Abolafia-Rozenzweig, N. Lybarger, Roland J. Viger, David P. Lesmes, Katherine Skalak, John Brakebill, Donald Walter Cline, Krista A. Dunne, K. Rasmussen, G. Miguez-Macho
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, Advanced Research Computing (ARC)

Sediment dynamics and implications for management: State of the science from long‐term research in the Chesapeake Bay watershed, USA

This review aims to synthesize the current knowledge of sediment dynamics using insights from long‐term research conducted in the watershed draining to the Chesapeake Bay, the largest estuary in the U.S., to inform management actions to restore the estuary and its watershed. The sediment dynamics of the Chesapeake are typical of many impaired watersheds and estuaries around the world...
Authors
Gregory Noe, Matthew J. Cashman, Katherine Skalak, Allen C. Gellis, Kristina G. Hopkins, Doug L. Moyer, James S. Webber, Adam Benthem, Kelly O. Maloney, John Brakebill, Andrew Sekellick, Michael J. Langland, Qian Zhang, Gary W. Shenk, Jennifer L. D. Keisman, Cliff R. Hupp
By
Ecosystems Land Change Science Program, Chesapeake Bay Activities, Florence Bascom Geoscience Center, Pennsylvania Water Science Center

An enhanced hydrologic stream network based on the NHDPlus medium resolution dataset

The National Hydrography Dataset Plus, Version 2.1 (NHDPlusV2.1) is an attribute-rich digital stream network for the conterminous United States, serving as a foundational infrastructure for reporting hydrologic information at both regional and national scales. SPAtially Referenced Regressions On Watershed attributes (SPARROW) is a process-based statistical model that relies on a digital...
Authors
John W. Brakebill, Gregory E. Schwarz, Michael E. Wieczorek
By
Water Resources Mission Area, National Hydrography

Catchment-level estimates of nitrogen and phosphorus agricultural use from commercial fertilizer sales for the conterminous United States, 2012

Nutrient inputs from commercial agricultural fertilizer, particularly nitrogen and phosphorus, are important factors contributing to the degradation of surface-water quality and the alteration of aquatic ecosystems. Despite this importance, information about the application of fertilizer to agricultural land is not available in a consistent manner across the United States at a scale...
Authors
Jana S. Stewart, Gregory E. Schwarz, John W. Brakebill, Stephen D. Preston
By
Upper Midwest Water Science Center

NHDPlus as a geospatial framework for SPARROW modeling

Successful water-resource management requires thorough knowledge and understanding of the relations among water-quality contaminate sources and the factors that affect the transport throughout a hydrologic system. Surface-water modeling is a valuable tool that can be applied to help advance and achieve the understanding of these dynamic relations. Spatially Referenced Regressions on...
Authors
John W. Brakebill, Gregory E. Schwarz
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, National Hydrography

Sources, fate, and transport of nitrogen and phosphorus in the Chesapeake Bay watershed: An empirical model

Spatially Referenced Regression on Watershed Attributes (SPARROW) was used to provide empirical estimates of the sources, fate, and transport of total nitrogen (TN) and total phosphorus (TP) in the Chesapeake Bay watershed, and the mean annual TN and TP flux to the bay and in each of 80,579 nontidal tributary stream reaches. Restoration efforts in recent decades have been insufficient to...
Authors
Scott W. Ator, John W. Brakebill, Joel D. Blomquist
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, Chesapeake Bay Activities

Digital hydrologic networks supporting applications related to spatially referenced regression modeling

Digital hydrologic networks depicting surface-water pathways and their associated drainage catchments provide a key component to hydrologic analysis and modeling. Collectively, they form common spatial units that can be used to frame the descriptions of aquatic and watershed processes. In addition, they provide the ability to simulate and route the movement of water and associated...
Authors
John W. Brakebill, David M. Wolock, Silvia Terziotti
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center

Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model

We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban...
Authors
J. W. Brakebill, S.W. Ator, G. E. Schwarz
By
Chesapeake Bay Activities

Synthesis of U.S. Geological Survey science for the Chesapeake Bay ecosystem and implications for environmental management

The purpose of this report is to present a synthesis of the USGS Chesapeake Bay science related to the 2001-06 goals and provide implications for environmental management. The report provides USGS findings that address the science needs of the Chesapeake Bay Program (CBP) restoration goals and includes summaries of 1. land-use change; 2. water quality in the watershed, including...
Authors
Scott W. Ator, Vicki S. Blazer, John W. Brakebill, Donald R. Cahoon, Peter R. Claggett, Thomas M. Cronin, Judith M. Denver, Christine L. Densmore, Allen C. Gellis, Cliff R. Hupp, Jurate M. Landwehr, Michael J. Langland, Christopher A. Ottinger, Milan J. Pavich, Matthew C. Perry, Scott W. Phillips, Stephen D. Preston, Jeff P. Raffensperger, Barnett A. Rattner, Nancy B. Rybicki, Debra A. Willard
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, Chesapeake Bay Activities

Proceedings of the U.S. Geological Survey Sixth Biennial Geographic Information Science Workshop, Denver, Colorado, April 24-28, 2006

The U.S. Geological Survey's (USGS) Sixth Biennial Geographic Information Science Workshop April 24 - 28, 2006, at the Denver Federal Center in Denver, Colorado, provides a unique opportunity for multi-disciplinary Geographic Information Systems (GIS) and associated scientific professionals to share, learn, present, and discuss a wide variety of geospatial-related topics. Information is...
Authors
John W. Brakebill, Jennifer B. Sieverling, Peter G. Chirico
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center

Digital 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...
Authors
John W. Brakebill, Stephen D. Preston
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, Chesapeake Bay Activities

ERF1_2 -- Enhanced River Reach File 2.0

The digital segmented network based on watershed boundaries, ERF1_2, includes enhancements to the U.S. Environmental Protection Agency's River Reach File 1 (RF1) (USEPA, 1996; DeWald and others, 1985) to support national and regional-scale surface water-quality modeling. Alexander and others (1999) developed ERF1, which assessed the hydrologic integrity of the digital reach traces and...
Authors
Jacqueline V. Nolan, John W. Brakebill, Richard B. Alexander, Gregory E. Schwarz
link
Spatial Distribution of incremental sediment yields in the Chesapeake Bay

Sediment Sources and Transport in the Chesapeake Bay Watershed

Prepared by Allen C. Gellis and John W. Brakebill, U.S. Geological Survey (March 2013)
By
Chesapeake Bay Activities
link

Sediment Sources and Transport in the Chesapeake Bay Watershed

Prepared by Allen C. Gellis and John W. Brakebill, U.S. Geological Survey (March 2013)
Learn More
link
Western shore of the Chesapeake Bay

Sources, Fate, and Transport of Nitrogen and Phosphorus in the Chesapeake Bay Watershed—Interpretations and Applications of Spatially Referenced Regression on Watershed Attributes (SPARROW) Nutrient Model Results

As the largest and most productive estuary in North America, Chesapeake Bay is a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades, however, by excessive inputs of nutrients (nitrogen and phosphorus) and sediment from contributing watersheds. In 2000, the bay was listed as “impaired” under the Clean Water Act, and in 2010, a Total Maximum...
By
Chesapeake Bay Activities
link

Sources, Fate, and Transport of Nitrogen and Phosphorus in the Chesapeake Bay Watershed—Interpretations and Applications of Spatially Referenced Regression on Watershed Attributes (SPARROW) Nutrient Model Results

As the largest and most productive estuary in North America, Chesapeake Bay is a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades, however, by excessive inputs of nutrients (nitrogen and phosphorus) and sediment from contributing watersheds. In 2000, the bay was listed as “impaired” under the Clean Water Act, and in 2010, a Total Maximum...
Learn More

SPARROW model input datasets and predictions of nitrogen loads in streams of the Chesapeake Bay watershed

This data release contains mean-annual total nitrogen (TN) loads predicted by a SPARROW model for individual stream and shoreline reaches in the Chesapeake watershed as defined by NHDPlus, a 1:100,000 scale representation of stream hydrography built upon the National Hydrography Dataset (NHD) (Horizon Systems, 2010). Also included are the input variables required to execute the model...
By
Chesapeake Bay Activities, Maryland-Delaware-D.C. Water Science Center

Dataset used for estimating catchment-level nitrogen and phosphorus fertilizer use from commercial fertilizer sales data for the Conterminous U.S., 2012

This dataset includes all of the variables that were used in predictive models to estimate nitrogen and phosphorus fertilizer use from commercial fertilizer sales data at the catchment/county level for the Conterminous U.S. for the year 2012. The dataset includes model input at the catchment/county level. A companion USGS Scientific Investigations Report describes the methods and...
By
Water Resources Mission Area, National Water Quality Program

E2NHDPlusV2_us: Database of Ancillary Hydrologic Attributes and Modified Routing for NHDPlus Version 2.1 Flowlines

The National Hydrography Dataset Plus, Version 2 (NHDPlusV2) is an attribute rich, digital hydrologic network for the Conterminous U.S. developed by the U.S. Environmental Protection Agency (EPA) and U.S. Geological Survey (USGS). SPAtially Referenced Regressions On Watershed attributes (SPARROW), is a process-based/statistical model that relies on a digital hydrologic network, like...
By
Water Resources Mission Area, National Wildlife Health Center

Input and predictions from a suspended-sediment SPARROW model CBSS_V2 in the Chesapeake Bay watershed

These data represent input and estimates from a medium-resolution (1:100,000 scale) NHDPlus SPAtially Referenced Regression on Watershed attributes (SPARROW) model for the Chesapeake Bay watershed (CBSS_v2). The model spatially correlates long-term mean annual suspended-sediment flux in 113 non-tidal streams to likely upland and stream-corridor sources, landscape factors affecting upland...
By
Chesapeake Bay Activities, Maryland-Delaware-D.C. Water Science Center

County-Level Estimates of Nitrogen and Phosphorus from Commercial Fertilizer for the Conterminous United States, 1987-2012

This data set contains county-level estimates of nitrogen and phosphorus from fertilizer, for both farm and nonfarm uses, for the conterminous United States, for 1987 through 2012. State-level farm and nonfarm nitrogen and phosphorus were derived from the Association of American Plant Food Control Officials (AAPFCO) commercial fertilizer sales data. State estimates were then allocated to...
By
Water Resources Mission Area, National Water Quality Program

Bootstrap-estimated land-to-water coefficients from the CBTN_v4 SPARROW model

This file contains 200 sets of bootstrap-estimated land-to-water coefficients from the CBTN_v4 SPARROW model, which is documented in USGS Scientific Investigations Report 2011-5167. The coefficients were produced as part of CBTN_v4 model calibration to provide information about the uncertainty in model estimates.
By
Maryland-Delaware-D.C. Water Science Center

Science and Products

Filter Total Items: 20

CONUS404: The NCAR-USGS 4-km long-term regional hydroclimate reanalysis over the CONUS

A unique, high-resolution, hydroclimate reanalysis, 40-plus-year (October 1979–September 2021), 4 km (named as CONUS404), has been created using the Weather Research and Forecasting Model by dynamically downscaling of the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate dataset (ERA5) over the conterminous United...
Authors
R. M. Rasmussen, F. Chen, C. H. Liu, K. Ikeda, A. Prein, J. Kim, T. Schneider, A. Dai, D. Gochis, A. Dugger, Y. Zhang, A. Jaye, J. Dudhia, C. He, M. Harrold, L. Xue, S. Chen, A. Newman, E. Dougherty, R. Abolafia-Rozenzweig, N. Lybarger, Roland J. Viger, David P. Lesmes, Katherine Skalak, John Brakebill, Donald Walter Cline, Krista A. Dunne, K. Rasmussen, G. Miguez-Macho
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, Advanced Research Computing (ARC)

Sediment dynamics and implications for management: State of the science from long‐term research in the Chesapeake Bay watershed, USA

This review aims to synthesize the current knowledge of sediment dynamics using insights from long‐term research conducted in the watershed draining to the Chesapeake Bay, the largest estuary in the U.S., to inform management actions to restore the estuary and its watershed. The sediment dynamics of the Chesapeake are typical of many impaired watersheds and estuaries around the world...
Authors
Gregory Noe, Matthew J. Cashman, Katherine Skalak, Allen C. Gellis, Kristina G. Hopkins, Doug L. Moyer, James S. Webber, Adam Benthem, Kelly O. Maloney, John Brakebill, Andrew Sekellick, Michael J. Langland, Qian Zhang, Gary W. Shenk, Jennifer L. D. Keisman, Cliff R. Hupp
By
Ecosystems Land Change Science Program, Chesapeake Bay Activities, Florence Bascom Geoscience Center, Pennsylvania Water Science Center

An enhanced hydrologic stream network based on the NHDPlus medium resolution dataset

The National Hydrography Dataset Plus, Version 2.1 (NHDPlusV2.1) is an attribute-rich digital stream network for the conterminous United States, serving as a foundational infrastructure for reporting hydrologic information at both regional and national scales. SPAtially Referenced Regressions On Watershed attributes (SPARROW) is a process-based statistical model that relies on a digital...
Authors
John W. Brakebill, Gregory E. Schwarz, Michael E. Wieczorek
By
Water Resources Mission Area, National Hydrography

Catchment-level estimates of nitrogen and phosphorus agricultural use from commercial fertilizer sales for the conterminous United States, 2012

Nutrient inputs from commercial agricultural fertilizer, particularly nitrogen and phosphorus, are important factors contributing to the degradation of surface-water quality and the alteration of aquatic ecosystems. Despite this importance, information about the application of fertilizer to agricultural land is not available in a consistent manner across the United States at a scale...
Authors
Jana S. Stewart, Gregory E. Schwarz, John W. Brakebill, Stephen D. Preston
By
Upper Midwest Water Science Center

NHDPlus as a geospatial framework for SPARROW modeling

Successful water-resource management requires thorough knowledge and understanding of the relations among water-quality contaminate sources and the factors that affect the transport throughout a hydrologic system. Surface-water modeling is a valuable tool that can be applied to help advance and achieve the understanding of these dynamic relations. Spatially Referenced Regressions on...
Authors
John W. Brakebill, Gregory E. Schwarz
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, National Hydrography

Sources, fate, and transport of nitrogen and phosphorus in the Chesapeake Bay watershed: An empirical model

Spatially Referenced Regression on Watershed Attributes (SPARROW) was used to provide empirical estimates of the sources, fate, and transport of total nitrogen (TN) and total phosphorus (TP) in the Chesapeake Bay watershed, and the mean annual TN and TP flux to the bay and in each of 80,579 nontidal tributary stream reaches. Restoration efforts in recent decades have been insufficient to...
Authors
Scott W. Ator, John W. Brakebill, Joel D. Blomquist
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, Chesapeake Bay Activities

Digital hydrologic networks supporting applications related to spatially referenced regression modeling

Digital hydrologic networks depicting surface-water pathways and their associated drainage catchments provide a key component to hydrologic analysis and modeling. Collectively, they form common spatial units that can be used to frame the descriptions of aquatic and watershed processes. In addition, they provide the ability to simulate and route the movement of water and associated...
Authors
John W. Brakebill, David M. Wolock, Silvia Terziotti
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center

Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model

We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban...
Authors
J. W. Brakebill, S.W. Ator, G. E. Schwarz
By
Chesapeake Bay Activities

Synthesis of U.S. Geological Survey science for the Chesapeake Bay ecosystem and implications for environmental management

The purpose of this report is to present a synthesis of the USGS Chesapeake Bay science related to the 2001-06 goals and provide implications for environmental management. The report provides USGS findings that address the science needs of the Chesapeake Bay Program (CBP) restoration goals and includes summaries of 1. land-use change; 2. water quality in the watershed, including...
Authors
Scott W. Ator, Vicki S. Blazer, John W. Brakebill, Donald R. Cahoon, Peter R. Claggett, Thomas M. Cronin, Judith M. Denver, Christine L. Densmore, Allen C. Gellis, Cliff R. Hupp, Jurate M. Landwehr, Michael J. Langland, Christopher A. Ottinger, Milan J. Pavich, Matthew C. Perry, Scott W. Phillips, Stephen D. Preston, Jeff P. Raffensperger, Barnett A. Rattner, Nancy B. Rybicki, Debra A. Willard
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, Chesapeake Bay Activities

Proceedings of the U.S. Geological Survey Sixth Biennial Geographic Information Science Workshop, Denver, Colorado, April 24-28, 2006

The U.S. Geological Survey's (USGS) Sixth Biennial Geographic Information Science Workshop April 24 - 28, 2006, at the Denver Federal Center in Denver, Colorado, provides a unique opportunity for multi-disciplinary Geographic Information Systems (GIS) and associated scientific professionals to share, learn, present, and discuss a wide variety of geospatial-related topics. Information is...
Authors
John W. Brakebill, Jennifer B. Sieverling, Peter G. Chirico
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center

Digital 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...
Authors
John W. Brakebill, Stephen D. Preston
By
Water Resources Mission Area, Maryland-Delaware-D.C. Water Science Center, Chesapeake Bay Activities

ERF1_2 -- Enhanced River Reach File 2.0

The digital segmented network based on watershed boundaries, ERF1_2, includes enhancements to the U.S. Environmental Protection Agency's River Reach File 1 (RF1) (USEPA, 1996; DeWald and others, 1985) to support national and regional-scale surface water-quality modeling. Alexander and others (1999) developed ERF1, which assessed the hydrologic integrity of the digital reach traces and...
Authors
Jacqueline V. Nolan, John W. Brakebill, Richard B. Alexander, Gregory E. Schwarz
link
Spatial Distribution of incremental sediment yields in the Chesapeake Bay

Sediment Sources and Transport in the Chesapeake Bay Watershed

Prepared by Allen C. Gellis and John W. Brakebill, U.S. Geological Survey (March 2013)
By
Chesapeake Bay Activities
link

Sediment Sources and Transport in the Chesapeake Bay Watershed

Prepared by Allen C. Gellis and John W. Brakebill, U.S. Geological Survey (March 2013)
Learn More
link
Western shore of the Chesapeake Bay

Sources, Fate, and Transport of Nitrogen and Phosphorus in the Chesapeake Bay Watershed—Interpretations and Applications of Spatially Referenced Regression on Watershed Attributes (SPARROW) Nutrient Model Results

As the largest and most productive estuary in North America, Chesapeake Bay is a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades, however, by excessive inputs of nutrients (nitrogen and phosphorus) and sediment from contributing watersheds. In 2000, the bay was listed as “impaired” under the Clean Water Act, and in 2010, a Total Maximum...
By
Chesapeake Bay Activities
link

Sources, Fate, and Transport of Nitrogen and Phosphorus in the Chesapeake Bay Watershed—Interpretations and Applications of Spatially Referenced Regression on Watershed Attributes (SPARROW) Nutrient Model Results

As the largest and most productive estuary in North America, Chesapeake Bay is a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades, however, by excessive inputs of nutrients (nitrogen and phosphorus) and sediment from contributing watersheds. In 2000, the bay was listed as “impaired” under the Clean Water Act, and in 2010, a Total Maximum...
Learn More

SPARROW model input datasets and predictions of nitrogen loads in streams of the Chesapeake Bay watershed

This data release contains mean-annual total nitrogen (TN) loads predicted by a SPARROW model for individual stream and shoreline reaches in the Chesapeake watershed as defined by NHDPlus, a 1:100,000 scale representation of stream hydrography built upon the National Hydrography Dataset (NHD) (Horizon Systems, 2010). Also included are the input variables required to execute the model...
By
Chesapeake Bay Activities, Maryland-Delaware-D.C. Water Science Center

Dataset used for estimating catchment-level nitrogen and phosphorus fertilizer use from commercial fertilizer sales data for the Conterminous U.S., 2012

This dataset includes all of the variables that were used in predictive models to estimate nitrogen and phosphorus fertilizer use from commercial fertilizer sales data at the catchment/county level for the Conterminous U.S. for the year 2012. The dataset includes model input at the catchment/county level. A companion USGS Scientific Investigations Report describes the methods and...
By
Water Resources Mission Area, National Water Quality Program

E2NHDPlusV2_us: Database of Ancillary Hydrologic Attributes and Modified Routing for NHDPlus Version 2.1 Flowlines

The National Hydrography Dataset Plus, Version 2 (NHDPlusV2) is an attribute rich, digital hydrologic network for the Conterminous U.S. developed by the U.S. Environmental Protection Agency (EPA) and U.S. Geological Survey (USGS). SPAtially Referenced Regressions On Watershed attributes (SPARROW), is a process-based/statistical model that relies on a digital hydrologic network, like...
By
Water Resources Mission Area, National Wildlife Health Center

Input and predictions from a suspended-sediment SPARROW model CBSS_V2 in the Chesapeake Bay watershed

These data represent input and estimates from a medium-resolution (1:100,000 scale) NHDPlus SPAtially Referenced Regression on Watershed attributes (SPARROW) model for the Chesapeake Bay watershed (CBSS_v2). The model spatially correlates long-term mean annual suspended-sediment flux in 113 non-tidal streams to likely upland and stream-corridor sources, landscape factors affecting upland...
By
Chesapeake Bay Activities, Maryland-Delaware-D.C. Water Science Center

County-Level Estimates of Nitrogen and Phosphorus from Commercial Fertilizer for the Conterminous United States, 1987-2012

This data set contains county-level estimates of nitrogen and phosphorus from fertilizer, for both farm and nonfarm uses, for the conterminous United States, for 1987 through 2012. State-level farm and nonfarm nitrogen and phosphorus were derived from the Association of American Plant Food Control Officials (AAPFCO) commercial fertilizer sales data. State estimates were then allocated to...
By
Water Resources Mission Area, National Water Quality Program

Bootstrap-estimated land-to-water coefficients from the CBTN_v4 SPARROW model

This file contains 200 sets of bootstrap-estimated land-to-water coefficients from the CBTN_v4 SPARROW model, which is documented in USGS Scientific Investigations Report 2011-5167. The coefficients were produced as part of CBTN_v4 model calibration to provide information about the uncertainty in model estimates.
By
Maryland-Delaware-D.C. Water Science Center
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