SPARROW Surface Water-Quality Modeling for Puget Sound
Project Website:
Puget Sound, WA Nutrient SPARROW Model | U.S. Geological Survey (usgs.gov)
Documentation for the Puget Sound SPARROW models
Schmadel, N.M., Figueroa-Kaminsky, C., Wise, D.R., Wasielewski, J.K., Johnson, Z.C., Black, R., 2025,
Preprint: Simulated seasonal loads of total nitrogen and total phosphorus by major source from watersheds draining to
Washington waters of the Salish Sea, 2005 through 2020. ESS Open Archive. February 05, 2025.
https://doi.org/10.22541/essoar.173878059.92247480/v1
Schmadel, N.M., Figueroa-Kaminsky, C., Wise, D.R., Wasielewski, J.K., Gala, J., Johnson, Z.C., 2024,
Model application and calibration load data for seasonally dynamic total nitrogen and total phosphorus
SPARROW models developed for watersheds draining to Washington waters of the Salish Sea, 2005 through 2020: U.S Geological Survey data release,
https://doi.org/10.5066/P9LY1PQF
Documentation of the modeling tool SPARROW (SPAtially Referenced Regression On Watershed
attributes)
Schwarz, G.E., A.B. Hoos, R.B. Alexander, and R.A. Smith, 2006. The SPARROW Surface
Water-Quality Model: Theory, Application, and User Documentation. U.S. Geological Survey
Techniques and Methods Report, Book 6, Chapter B3.
https://pubs.usgs.gov/tm/2006/tm6b3/;
Preston, S.D., Alexander, R.B., Woodside, M.D., and Hamilton, P.A., 2009, SPARROW MODELING
- Enhancing Understanding of the Nation's Water Quality: U.S. Geological Survey Fact Sheet
2009-3019, 6 p.
https://pubs.usgs.gov/fs/2009/3019/
Documentation of the USGS Watershed Boundary Dataset
U.S. Geological Survey. Watershed Boundary Dataset,
https://www.usgs.gov/national-hydrography/watershed-boundary-dataset
The relationship between the scale of reporting of model results and uncertainty:
The SPARROW model is, in theory, scale independent. However, the uncertainty associated with
SPARROW predictions of accumulated load is expected to decrease with increasing watershed size.
The original SPARROW results represented conditions at the incremental catchment scale, which had
an average size of 3.0 square kilometers. Those results were aggregated to the HUC12 watershed scale
for this mapping application. There were 404 HUC12 watersheds, which had an average size of 88 square kilometers.
Mean Aggregated Yield:
The sum of the seasonally averaged incremental loads within a HUC12 watershed divided by the total area of the watershed.
Incremental Load:
The predicted load leaving a stream reach that represents only the contribution from sources located within the incremental
drainage area for that reach. The incremental drainage area for a stream is the area that drains directly to a reach without passing
through another reach.
Accumulated Load:
The predicted load exported from a HUC12 watershed that represents the contribution from all sources located within the entire area
draining to the watershed outlet (which could include other upstream watersheds).
Mean Seasonal Accumulated Load:
The seasonally averaged accumulated load exported from a HUC12 watershed.
Definitions for “Nutrient Impaired Waterbodies” layer:
- Name: Name of impaired water body.
- WBID: Code used by Washington Department of Ecology to identify the nutrient-impaired water body.
- Reach ID: Reach identifier from NHDPlus Version 2.
USGS Data Disclaimer:
Unless otherwise stated, all data, metadata and related materials are considered to
satisfy the quality standards relative to the purpose for which the data were collected.
Although these data and associated metadata have been reviewed for accuracy and completeness
and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied
is made regarding the display or utility of the data for other purposes, nor on all computer
systems, nor shall the act of distribution constitute any such warranty.
USGS Software Disclaimer:
This software has been approved for release by the U.S. Geological Survey (USGS). Although
the software has been subjected to rigorous review, the USGS reserves the right to update
the software as needed pursuant to further analysis and review. No warranty, expressed or
implied, is made by the USGS or the U.S. Government as to the functionality of the software
and related material nor shall the fact of release constitute any such warranty. Furthermore,
the software is released on condition that neither the USGS nor the U.S. Government shall
be held liable for any damages resulting from its authorized or unauthorized use.
USGS Product Names Disclaimer:
Any use of trade, firm, or product names is for descriptive purposes only and does not
imply endorsement by the U.S. Government.
This web application functions best in Chrome, Firefox, or Safari. Internet Explorer works but with slower performance.
This web application has been made possible by the following open-source projects:
Lobipanel
https://github.com/arboshiki/lobipanel
Boostrap Select
https://silviomoreto.github.io/bootstrap-select
Version v0.9.0
Link to SPARROW REST Services:
SPARROW
Puget Sound REST Services
