Updates to the Suspended Sediment SPARROW Model Developed for Western Oregon and Northwestern California

Scientific Investigations Report 2018-5156
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Abstract

A SPARROW (SPAtially Related Regressions On Watershed attributes) model that was previously developed for western Oregon and northwestern California was updated using advancements in the SPARROW software and refinements to the input data. As was the case for the original model calibration, the updated models used the NHD Plus Version 2 as a hydrologic framework and relied on the same estimates of long-term mean suspended-sediment loads and watershed attributes. The updated calibration results indicated that two different SPARROW models were possible—one model from which sediment sources were represented by local lithology and one from which sediment sources were represented by generalized land-cover classes; precipitation, catchment slope, wildfire disturbance, and sediment loss in impoundments were significantly correlated with suspended-sediment loads in both models. The updated models also included a method to compensate for the bias introduced by using total suspended solids to represent suspended sediment in the calibration dataset—a feature that was not available during the original model calibration. The effect of this feature was an overall increase in estimated suspended-sediment loads. Although the lithology- and the land-cover based models used different landscape properties to describe sediment sources, each could be useful in specific applications. The lithology-based model provides more accurate estimates of suspended-sediment load, but the land-cover based model allows water-quality managers to estimate how much in-stream suspended-sediment load originates in areas with extensive development compared to the load that originates in areas with relatively little human impact.

Suggested Citation

Wise, D.R., 2018, Updates to the suspended sediment SPARROW model developed for western Oregon and northeastern California: U.S. Geological Survey Scientific Investigations Report 2018–5156, 23 p., https://doi.org/10.3133/sir20185156.

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Description of the Modeling Domain
  • Methods
  • Calibration Results and Predictions
  • Interpretation of Results from the Updated SPARROW Suspended Sediment Models
  • Differences Between the Original and Updated Suspended Sediment SPARROW Models
  • Application of the Updated Suspended Sediment SPARROW Models
  • Summary
  • References Cited
  • Appendix 1. Summary of Calibration Data for the Updated Suspended Sediment SPARROW Models Developed for Western Oregon and Northwestern California

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Updates to the suspended sediment SPARROW model developed for western Oregon and northeastern California
Series title Scientific Investigations Report
Series number 2018-5156
DOI 10.3133/sir20185156
Year Published 2018
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Oregon Water Science Center
Description Report: v, 23 p.; Appendix; Data Release
Country United States
State California, Oregon
Online Only (Y/N) Y