This data release contains input and output data tables from a SPAtially Referenced Regression On Watershed attributes (SPARROW) model, which estimated total nitrogen loads in streams of the Chesapeake Bay watershed under varying better management practice (BMP) implementation scenarios. Further documentation about the SPARROW modeling framework can be found here: https://pubs.er.usgs.gov/publication/tm6B3. A model archive containing inputs, outputs, code, and helpful spatial data is also included as a zipped folder. This model archive can be used to recreate the output provided in this data release. The model archive includes a read me text file that documents the contents of the archive and how it can be used. SPARROW_Inputs.csv includes spatial information about nitrogen sources, landscape characteristics, and hydrology from the year 2012 for use with the SPARROW model. SPARROW_Output_BaseBMP.csv includes SPARROW model output for the base model that does not include a BMP variable. SPARROW_Output_HighBMP.csv includes SPARROW model output for the model that includes a high-impact BMP variable. SPARROW_Output_OtherBMP.csv includes SPARROW model output for the model that includes a other-impact BMP variable.

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, including landscape characteristics, nutrient inputs to land, and calibration data from water quality monitoring stations. Further details on model construction and results are described in Ator (2011, https://doi.org/10.3133/sir20115167).

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, including landscape characteristics, nutrient inputs to land, and calibration data from water quality monitoring stations. Further details on model construction and results are described in Ator (2011, https://doi.org/10.3133/sir20115167).

The U.S. Geological Survey's (USGS) SPAtially Referenced Regression On Watershed attributes (SPARROW) model was used to aid in the interpretation of monitoring data and simulate streamflow and water-quality conditions in streams across the Northeast Region of the United States. SPARROW is a hybrid empirical/process-based mass balance model that can be used to estimate the major sources and environmental factors that affect the long-term supply, transport, and fate of contaminants in streams. The spatially explicit model structure is defined by a river reach network coupled with contributing catchments. The model is calibrated by statistically relating watershed sources and transport-related properties to monitoring-based water-quality load estimates. This USGS data release includes input and output files associated with 2012 SPARROW simulations of streamflow, total nitrogen, total phosphorus and suspended-sediment load in streams of the Northeast region. Model construction, calibration and results are described in Ator (2019, https://doi.org/10.3133/sir20195118).

The U.S. Geological Survey's (USGS) SPAtially Referenced Regression On Watershed attributes (SPARROW) model was used to aid in the interpretation of monitoring data and simulate streamflow and water-quality conditions in streams across the Northeast Region of the United States. SPARROW is a hybrid empirical/process-based mass balance model that can be used to estimate the major sources and environmental factors that affect the long-term supply, transport, and fate of contaminants in streams. The spatially explicit model structure is defined by a river reach network coupled with contributing catchments. The model is calibrated by statistically relating watershed sources and transport-related properties to monitoring-based water-quality load estimates. This USGS data release includes input and output files associated with 2012 SPARROW simulations of streamflow, total nitrogen, total phosphorus and suspended-sediment load in streams of the Northeast region. Model construction, calibration and results are described in Ator (2019, https://doi.org/10.3133/sir20195118).

This U.S. Geological Survey data release contains datasets that combine past data with future projections of nitrogen sources and nitrogen export to the Chesapeake Bay watershed for the years 1950-2050. To help understand the effect of human and environmental changes over this time period, data for nitrogen sources from wastewater, agricultural fertilizer and manure, and atmospheric deposition are combined with datasets of population and land use. These datasets were used in conjunction with a previously calibrated SPAtially Referenced Regression On Watershed attributes (SPARROW) modeling tool to estimate the mean annual loads of total nitrogen to the Chesapeake Bay and nontidal stream reaches in the watershed at a decadal timestep from 1950-2050. SPARROW model output of incremental and total loads for each reach in the Chesapeake Bay watershed are reported in this data release.

This U.S. Geological Survey data release contains datasets that combine past data with future projections of nitrogen sources and nitrogen export to the Chesapeake Bay watershed for the years 1950-2050. To help understand the effect of human and environmental changes over this time period, data for nitrogen sources from wastewater, agricultural fertilizer and manure, and atmospheric deposition are combined with datasets of population and land use. These datasets were used in conjunction with a previously calibrated SPAtially Referenced Regression On Watershed attributes (SPARROW) modeling tool to estimate the mean annual loads of total nitrogen to the Chesapeake Bay and nontidal stream reaches in the watershed at a decadal timestep from 1950-2050. SPARROW model output of incremental and total loads for each reach in the Chesapeake Bay watershed are reported in this data release.

This U.S. Geological Survey (USGS) data release includes input and output tabular files associated with mean seasonal 2002 simulations of total nitrogen and total phosphorus loads of the northeastern United States. The mean seasonal (MS) simulations are performed using a dynamic configuration of the USGS’s Spatially Referenced Regression On Watershed attributes (dynamicSPARROW-MS) model, nonlinear regression techniques, and monitored data. Model development, calibration, and results are described in the related external resource (Schmadel et al., 2021).

This U.S. Geological Survey (USGS) data release includes input and output tabular files associated with mean seasonal 2002 simulations of total nitrogen and total phosphorus loads of the northeastern United States. The mean seasonal (MS) simulations are performed using a dynamic configuration of the USGS’s Spatially Referenced Regression On Watershed attributes (dynamicSPARROW-MS) model, nonlinear regression techniques, and monitored data. Model development, calibration, and results are described in the related external resource (Schmadel et al., 2021).

The United States Geological Survey’s (USGS) SPAtially Referenced Regressions On Watershed attributes (SPARROW) model was developed to aid in the interpretation of monitoring data and simulate water-quality conditions in streams across large spatial scales. SPARROW is a hybrid empirical⁄process-based mass balance model that can be used to estimate the major sources and environmental factors that affect the long-term supply, transport, and fate of contaminants in streams. The spatially explicit model structure is defined by a river reach network coupled with contributing catchments. The model is calibrated by statistically relating watershed sources and transport-related properties to monitoring-based water-quality load estimates. Load estimates used in recent Midcontinent SPARROW model applications (2002 base year) are described in Saad and others, 2018 (https://doi.org/10.3133/sir20185051). Load estimation methods described in this report include the Beale Ratio Estimator and Fluxmaster models. This USGS data release, prepared in cooperation with the International Joint Commission, contains all of the input and output files necessary to reproduce the load estimates considered for inclusion in the 2002 Midcontinent SPARROW models. Data preparation for input to the load estimation models is also fully described in the above-mentioned report.