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 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 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 includes 5 files containing model inputs and resulting model predictions. A previously-calibrated spatially referenced regression (SPARROW) model was used to estimate effects of climate change on in-stream nitrogen (TN) loads in the Chesapeake Bay watershed between 1995 and 2025. Model scenarios were run using data for nitrogen sources and landscape characteristics from 2012, changing only temperature and runoff using climate change predictions to evaluate the change in climate on TN loads. Confidence intervals for model output predictions are also included.

This data release includes 5 files containing model inputs and resulting model predictions. A previously-calibrated spatially referenced regression (SPARROW) model was used to estimate effects of climate change on in-stream nitrogen (TN) loads in the Chesapeake Bay watershed between 1995 and 2025. Model scenarios were run using data for nitrogen sources and landscape characteristics from 2012, changing only temperature and runoff using climate change predictions to evaluate the change in climate on TN loads. Confidence intervals for model output predictions are also included.

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 (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).

This USGS data release contains datasets, metadata, and figures associated with estimating nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology. There are three shapefiles with associated metadata and figures representing the shapefiles: • Catchments_GWcontribN.shp: NHDPlus catchment estimates of groundwater contribution of nitrate to streams in the Chesapeake Bay watershed • HUC12_GWcontribN.shp: HUC 12 estimates of groundwater contribution of nitrate to streams in the Chesapeake Bay watershed • Sites_GWcontribN.shp: Sites with baseflow measurements for nitrate plus nitrite within the Chesapeake Bay watershed These data support the following publication: • Terziotti, Silvia, Capel, P.D., Tesoriero, A.J., Hopple, J.A., and Kronholm, S.C., 2017, Estimates of nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology: U.S. Geological Survey Scientific Investigations Report 2017-5160, 20 p., https://doi.org/10.3133/sir20175160.