RSPARROW versions of previously developed SAS-based models of streamflow, suspended-sediment, total nitrogen, and total phosphorus conditions in the Midwest, Northeast, Pacific, Southeast, and Southwest Regions of the United States for water years 2000 -

The USGS Spatially Referenced Regression on Watershed attributes (SPARROW) model is a hybrid empirical/process-based mass balance model that can be used to estimate the major sources and environmental factors that affect the supply, transport, and fate of contaminants in streams and surface-water impoundments (Schwarz and others, 2006). This data release includes a set of 20 regional models that were converted from previously developed SAS-based models for the Midwest, Northeast, Pacific, Southeast, and Southwest Regions of the United States (Ator, 2019; Hoos and Roland, 2019; Robertson and Saad, 2019; Wise, 2019; Wise and others, 2019) to the R version of SPARROW (Sanisaca and Alexander, 2023). The original SAS models were developed to estimate streamflow, suspended-sediment, total nitrogen, and total phosphorus conditions. The models represent mean annual conditions for water years 2000 to 2014, centered on a modeling base year of 2012. No changes were made to the original SAS model inputs or settings during the conversion of the SAS models to RSPARROW, but there were small differences between the SAS and RSPARROW results. This was due to differences between the optimization routines used by the SAS SPARROW and RSPARROW models for minimizing residuals. The data release consists of five child items that contain the modeling files and metadata for each of the five regions.

References:
Ator, S.W., 2019, Spatially referenced models of streamflow and nitrogen, phosphorus, and suspended-sediment loads in streams of the Northeastern United States: U.S. Geological Survey Scientific Investigations Report 2019–5118, 57 p., https://doi.org/10.3133/sir20195118.

Hoos, A.B., and Roland, V.L. II, 2019, Spatially referenced models of streamflow and nitrogen, phosphorus, and suspended-sediment loads in the Southeastern United States: U.S. Geological Survey Scientific Investigations Report 2019–5135, 91 p., https://doi.org/10.3133/sir20195135.
 
Robertson, D.M., and Saad, D.A., 2019, Spatially referenced models of streamflow and nitrogen, phosphorus, and suspended-sediment loads in streams of the Midwestern United States: U.S. Geological Survey Scientific Investigations Report 2019–5114, 74 p. including 5 appendixes, https://doi.org/10.3133/sir20195114.
 
Wise, D.R., 2019, Spatially referenced models of streamflow and nitrogen, phosphorus, and suspended-sediment loads in streams of the Pacific region of the United States (ver. 1.1, June 2020): U.S. Geological Survey Scientific Investigations Report 2019-5112, 64 p., https://doi.org/10.3133/sir20195112.
 
Wise, D.R., Anning, D.W., and Miller, O.L., 2019, Spatially referenced models of streamflow and nitrogen, phosphorus, and suspended-sediment transport in streams of the southwestern United States (ver. 1.1, June 2020): U.S. Geological Survey Scientific Investigations Report 2019-5106, 66 p., https://doi.org/10.3133/sir20195106. 
 
Schwarz, G.E., Hoos, A.B., Alexander, R.B., and Smith, R.A., 2006, Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation: U.S. Geological Survey Techniques and Methods, 6–B3, https://pubs.er.usgs.gov/publication/tm6B3.