USGS - science for a changing world

Open-File Report 2008–1205

A Preliminary SPARROW Model of Suspended Sediment for the Conterminous United States

Gregory E. Schwarz

Graphic from PDF.

PDF (1.19 mb)

This report describes the results of a preliminary Spatially Referenced Regression on Watershed attributes (SPARROW) model of suspended sediment for the conterminous United States. The analysis is based on flux estimates compiled from more than 1,800 long-term monitoring stations operated by the U.S. Geological Survey (USGS) during the period 1975-2007. The SPARROW model is structured on the Reach File 1 (RF1) stream network, consisting of approximately 62,000 reach segments. The reach network has been modified to include more than 4,000 reservoirs, an important landscape feature affecting the delivery of suspended sediment. The model identifies six sources of sediment, including the stream channel and five classes of land use: urban, forested, Federal nonforested, agricultural and other, and noninundated land. The delivery of sediment from landform sources to RF1 streams is mediated by soil permeability, erodibility, slope, and rainfall; streamflow is found to affect the amount of sediment mobilized from the stream channel. The results show agricultural land and the stream channel to be major sources of sediment flux. Per unit area, Federal nonforested and urban lands are the largest landform sediment sources. Reservoirs are identified as major sites for sediment attenuation. This report includes a description for how the model results can be used to assess changes in instream sediment flux and concentration resulting from proposed changes in the regulation of sediment discharge from construction sites.

For more information, please contact author.

Suggested citatation:
Schwarz, G.E., 2008, A Preliminary SPARROW model of suspended sediment for the conterminous United States: U.S. Geological Survey Open-File Report 2008–1205, 8 p., available only online at

This document is available online only in Portable Document Format (PDF); the latest version of Adobe Acrobat Reader or similar software is required to view it. Download the latest version of Acrobat Reader, free of charge or go to for free tools that allow visually impaired users to read PDF files.

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Web Administrator
Page Last Modified: Wednesday, 07-Dec-2016 21:20:34 EST