Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation

Techniques and Methods 6-B3
By: , and 



SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds containing the stations. The core of the model consists of a nonlinear regression equation describing the non-conservative transport of contaminants from point and diffuse sources on land to rivers and through the stream and river network. The model predicts contaminant flux, concentration, and yield in streams and has been used to evaluate alternative hypotheses about the important contaminant sources and watershed properties that control transport over large spatial scales.

This report provides documentation for the SPARROW modeling technique and computer software to guide users in constructing and applying basic SPARROW models. The documentation gives details of the SPARROW software, including the input data and installation requirements, and guidance in the specification, calibration, and application of basic SPARROW models, as well as descriptions of the model output and its interpretation. The documentation is intended for both researchers and water-resource managers with interest in using the results of existing models and developing and applying new SPARROW models.

The documentation of the model is presented in two parts. Part 1 provides a theoretical and practical introduction to SPARROW modeling techniques, which includes a discussion of the objectives, conceptual attributes, and model infrastructure of SPARROW. Part 1 also includes background on the commonly used model specifications and the methods for estimating and evaluating parameters, evaluating model fit, and generating water-quality predictions and measures of uncertainty. Part 2 provides a user's guide to SPARROW, which includes a discussion of the software architecture and details of the model input requirements and output files, graphs, and maps. The text documentation and computer software are available on the Web at

Suggested Citation

Schwarz, G.E., Hoos, A.B., Alexander, R.B., and Smith, R.A., 2006, Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation: U.S. Geological Survey Techniques and Methods, 6–B3,

ISSN: 2328-7055 (online)

ISSN: 2328-7047 (print)

Table of Contents

  • Abstract
  • Acknowledgment
  • Part 1: A theoretical and practical Intorudction to SPARROW
  • Part 2: SPARROW User's Guide
  • Appendix A. Determination of the Bootstrap Confidence Interval Quantiles
  • Appendix B. Hydrologic Network Development
  • Appendix C. SAS/GIS Mapfile Creation
  • Appendix D. Descriptions of Output Files
Publication type Report
Publication Subtype USGS Numbered Series
Title Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation
Series title Techniques and Methods
Series number 6-B3
DOI 10.3133/tm6B3
Year Published 2006
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) National Water Quality Laboratory
Description 248 p.
Larger Work Type Report
Larger Work Subtype USGS Numbered Series
Larger Work Title Section B: Ground-water techniques in Book 3: Applications of hydraulics
Online Only (Y/N) N
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details