Spatial Regional Regression on Watershed Attributes (SPARROW)

Purpose

SPARROW models are used to estimate long-term average values of water characteristics, such as the amount of a contaminant that is delivered downstream, on the basis of existing monitoring data, location and strength of contaminant sources, and characteristics of the landscape.

Modeling results can help managers determine how to reduce loads of contaminants and design protection strategies; design strategies to meet regulatory requirements; predict changes in water quality that might result from management actions; and identify gaps and priorities in monitoring.

Description

SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modelling technique developed by the USGS in the late 90s. Its primary use is to estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources.  SPARROW models explore relations between human activities, natural processes, and contaminant transport using interactive Mappers.

SPARROW Graphic

 

SPARROW models are used to estimate long-term average values of water characteristics, such as the amount of a contaminant that is delivered downstream, on the basis of existing monitoring data, location and strength of contaminant sources, and characteristics of the landscape. The model was initially developed to;

  • Utilize monitoring data and watershed information to better explain the factors that affect water quality,
  • Examine the statistical significance of contaminant sources, environmental factors, and transport processes in explaining predicted contaminant loads
  • Provide a statistical basis for estimating stream loads in unmonitored locations.

Statistical methods are used in SPARROW modelling to explain in-stream measurements of water quality (constituent mass or load) in relation to upstream sources and watershed properties (soil characteristics, precipitation amounts, and land cover) that influence the transport of constituents to streams and their delivery to receiving water bodies, including estuaries.

The sparrow model once set up for a given catchment or study area can be useful in enhancing a monitoring plan by identifying additional sampling sites which adds to optimizing monitoring, reducing statistical uncertainty and better meeting modelling objectives.

Modelling results can help managers better understand spatial variations in pollution sources and the environmental and hydrologic processes that control their transport and dispersal. The direct result of this is that managers are better informed to determine how to reduce loads of contaminants and design protection strategies; design strategies to meet regulatory requirements; predict changes in water quality that might result from management actions; and identify gaps and priorities in monitoring.

SPARROW models are flexible—they can be applied to any region where there are specific needs for water-quality information and where data to support modelling are abundant. SPARROW models can be applied in any part of the world where sufficient data are available to support model development. A model was developed for New Zealand to identify the primary sources of nutrients to streams (Alexander et al., 2002)

Latest Version 2.9
State of Development Stable Release
Current Development Activity Still active development. Mostly going into US national and regional applications.

Development Contact

Sandy Elliott
s.elliott@niwa.co.nz
+64 7 8591839
National Institute of Water and Atmospheric Research

Scope

Intended End Users Direct users are specialist catchment modellers, but intended broader use is for water management.
Spatial Dimensions Unknown
Temporal Resolutions Not applicable
Temporal Extents Not applicable
Steady State or Dynamic Steady State

Input & Output Data

Accessibility

Open/Closed Source Unknown
Licence Type Free

User Information

Operating Systems MS Windows, Linux
Software Needed Unknown
User Interface Please Select
Ease of Use Moderate
Documentation

Documentation and Software download page

Support No formal support, although the authors are willing to assist.
Users Forum Not available.

Technical Considerations

Programming Language SAS (statistical software system) macro language, including IML language within SAS. Also uses some dll's originating in Fortran.
Methods included for calibration and validation Constrained non-linear least squares
Analytical Techniques Input/output
Model Structure

SPARROW model components

Linkages to other Models
Links

The prediction component of NZ Sparrow applications have been re-coded in VB and Fortran and incorporated into CLUES.

Sparrow home page - http://water.usgs.gov/nawqa/sparrow/ 

CLUES home page - https://www.niwa.co.nz/freshwater-and-estuaries/our-services/catchment-modelling/clues-catchment-land-use-for-environmental-sustainability-model

Key References

The SPARROW Surface Water-Quality Model: Theory, Application and User Documentation. U.S. Geological Survey Techniques and Methods, Book 6, Section B, Chapter 3

SPARROW MODELING—Enhancing Understanding of the Nation’s Water Quality: https://pubs.usgs.gov/fs/2009/3019/pdf/fs_2009_3019.pdf