Long Island Sound Spatially Referenced Regressions on Watershed Attributes (SPARROW) Models
The U.S. Geological Survey, New England Water Science Center, in collaboration with the U.S. Environmental Protection Agency (EPA), is modeling seasonal nutrient loads to Long Island Sound (LIS). Nutrients that originate from within the 41,867-square-mile section of the LIS watershed that is north of the Sound include both point (specific) and nonpoint (widespread) sources. Dynamic modeling of the system over a 20-year period (2000-2020) improves understanding of the source and delivery of nutrients (nitrogen and phosphorus) to LIS and how it varies seasonally. Model results will aid management decisions by evaluating source contributions and providing estimates of water-quality conditions.
The models fill in data gaps in unmonitored areas by providing estimates of nutrient sources and delivery for every stream reach within the watershed based on data from nutrient-load measurement sites in the watershed. Sources include nutrients from agricultural sources (such as fertilizer and manure), different land uses, snow cover, atmospheric deposition, and point discharges (such as wastewater treatment plants).
Additionally, responses to changes in both point and nonpoint source loads are included in the models. The effect of these responses (large or small) on the thousands of unmonitored reaches throughout the watershed, as well as the effects of loads to coastal embayments and the Sound, are estimated.
Better understanding of nutrient sources, transport, and how they vary seasonally will inform decision making. The SPARROW models also enable users to conduct scenarios to evaluate impacts of potential changes within the watershed, which also can advise management decisions.
This work provides the foundation for the EPA’s River Basin Export Reduction Optimization Support Tool (RBEROST), which will be used by EPA and others to evaluate and optimize best management practices for downstream load reductions to Long Island Sound.
The U.S. Geological Survey, New England Water Science Center, in collaboration with the U.S. Environmental Protection Agency (EPA), is modeling seasonal nutrient loads to Long Island Sound (LIS). Nutrients that originate from within the 41,867-square-mile section of the LIS watershed that is north of the Sound include both point (specific) and nonpoint (widespread) sources. Dynamic modeling of the system over a 20-year period (2000-2020) improves understanding of the source and delivery of nutrients (nitrogen and phosphorus) to LIS and how it varies seasonally. Model results will aid management decisions by evaluating source contributions and providing estimates of water-quality conditions.
The models fill in data gaps in unmonitored areas by providing estimates of nutrient sources and delivery for every stream reach within the watershed based on data from nutrient-load measurement sites in the watershed. Sources include nutrients from agricultural sources (such as fertilizer and manure), different land uses, snow cover, atmospheric deposition, and point discharges (such as wastewater treatment plants).
Additionally, responses to changes in both point and nonpoint source loads are included in the models. The effect of these responses (large or small) on the thousands of unmonitored reaches throughout the watershed, as well as the effects of loads to coastal embayments and the Sound, are estimated.
Better understanding of nutrient sources, transport, and how they vary seasonally will inform decision making. The SPARROW models also enable users to conduct scenarios to evaluate impacts of potential changes within the watershed, which also can advise management decisions.
This work provides the foundation for the EPA’s River Basin Export Reduction Optimization Support Tool (RBEROST), which will be used by EPA and others to evaluate and optimize best management practices for downstream load reductions to Long Island Sound.