USGS Release of Assessing Nutrient Inputs to the Nation's Estuaries and Great Lakes
Posted Tuesday, February 25, 2014 1:24 PM
By Wilber, William
New maps and data tables that describe nutrient loading to major estuaries throughout the conterminous U.S. are now available online on the National Water-Quality Assessment (NAWQA) Program web page titled Tracking the Source and Quantity of Nutrients to the Nation's Estuaries. These new web pages describe the major sources and contributing areas of nutrients to 115 estuaries along the Atlantic Coast, Gulf of Mexico, and the Pacific Northwest coast and from 160 watersheds draining into the Great Lakes.
In addition to the new web pages, water resource managers interested in a particular stream, reservoir, or estuary can use the online, interactive SPARROW model Decision-Support System (DSS) to estimate how reductions in nutrient sources affect downstream nutrient loads at a stream outlet. A new reporting feature within the DSS provides summary information on the amounts and sources of nutrients from upstream states or major hydrologic regions. For instance, output from the new reporting feature shows the amount of nitrogen contributed from each of the 31 states that drain into the Gulf of Mexico from the Mississippi River Basin.
This combination of national maps and an online decision support system are provided to improve access to water-quality modeling information that can be used in the development of nutrient reduction strategies and inform nutrient policies across the Nation.
Successful management of our Nation’s waters requires an integrated approach that includes both monitoring and modeling to understand which sources and areas are contributing the largest amounts of nutrients to local streams and ultimately to our Nation’s estuaries. These maps and data tables were produced using the USGS SPARROW (SPAtially Referenced Regressions on Watershed attributes) nutrient models. The SPARROW models incorporate geospatial data on geology, soils, land use, fertilizer, manure, wastewater treatment facilities, temperature, precipitation and other watershed characteristics, from USGS, NOAA, USDA, and USEPA linked to measurements of stream flow from USGS streamgages and water-quality monitoring data from more than 2,700 sites operated by 73 monitoring agencies.
A training session on the use of the SPARROW models will be held Wednesday, February 26 from 11:15 to noon at the 2014 National Estuary Program Meeting in Washington DC.
Additional information on USGS nutrient monitoring and modeling activities by the NAWQA program are available online.
William G. Wilber
Chief, National Water Quality Assessment Program
U.S. Geological Survey
413 National Center
12201 Sunrise Valley Dr.
Reston, VA 20192
(703) 648-6878 (Office)
(703) 343-5948 (Cell)