SPARROW Surface Water-Quality Modeling Web Pages
National Website:
https://water.usgs.gov/nawqa/sparrow/
Documentation of the SPARROW model for the National Dissolved Solids
Anning, D.W, and Flynn, M.E., 2014, Dissolved-solids sources, loads, yields, and concentrations
in streams of the conterminous United States: U. S. Geological Survey Scientific Investigations
Report 2014-5012, 101 p.,
http://dx.doi.org/10.3133/sir20145012.
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/
The relationship between the scale of reporting of model results and uncertainty:
Model results can be displayed at several watershed scales.
The smallest scale that could be used for reporting is the catchment
scale at which model computations are made for the national model;
these are RF1 catchments, typical watershed size is about 100 square miles.
Results can be aggregated up to larger scales for reporting including hydrologic units (HUC8, HUC4, HUC2)
and state scales. The SPARROW model is, in theory, scale independent.
However, the uncertainty associated with SPARROW predictions is expected to
increase for drainage basin sizes smaller than those of stream monitoring
sites used to calibrate the model.
Incremental Load
The predicted mean annual load of the constituent (kilograms per year) leaving a stream
reach that reflects only those sources contributed from within the incremental drainage area
of that reach. The incremental load value includes the effects of in-stream attenuation processes
associated with one half of the incremental reach length. Incremental drainage areas are
represented here as “catchments”. For the purposes of mapping, all lithology source variables were aggregated
into a single source variable, called lithology,with the exception of water
(submerged lithologies).
Accumulated Load (often referred to as "Total Load")
The predicted mean annual load of the constituent (kilograms per year) leaving a stream
reach that reflects the accumulated mass of the constituent contributed by all sources in
the total drainage area upstream of the reach outlet. The accumulated load value includes
the effects of in-stream attenuation processes in all upstream reaches.
Aggregated Load
For results grouped by 8-digit HUC, 6-digit HUC, 4-digit HUC, or state, aggregated
load represents the sum of incremental loads for those selected areas. Results aggregated
by State include input from catchments that cross state borders. For these catchments, the
loads were assumed to be uniformly distributed throughout the catchment. Therefore, inputs
from a given State were based on the percentage of the catchment in each state.
Incremental Yield
The Incremental Load divided by the incremental drainage area of the reach. Units are
kilograms per square kilometer per year.
Accumulated Yield
The Accumulated Load divided by the total drainage area upstream of the reach outlet.
Units are kilograms per square kilometer per year.
Aggregated Yield
The Aggregated Load divided by the sum of the “grouped by” incremental drainage areas.
Units are kilograms per square kilometer per year.
Delivered Incremental Load
Incremental load multiplied by the delivery fraction. Delivery fraction is defined
below.
Delivered Accumulated Load
Accumulated load multiplied by the delivery fraction. Delivery fraction is defined
below.
Delivered Aggregated Load
For results grouped by 8-digit HUC, 6-digit HUC, 4-digit HUC, or state, delivered
aggregated load represents the sum of delivered incremental loads for those selected areas.
Delivery fraction is defined below. Results aggregated by State include input from catchments
that cross state borders. For these catchments, the loads were assumed to be uniformly distributed
throughout the catchment. Therefore, inputs from a given State were based on the percentage
of the catchment in each state.
Delivered Incremental Yield
The Delivered Incremental Load divided by the incremental drainage area of the reach.
Units are kilograms per square kilometer per year.
Delivered Accumulated Yield
The Delivered Accumulated Load divided by the total drainage area upstream of the reach
outlet or total of the “grouped by” area. Units are kilograms per square kilometer per year.
Delivered Aggregated Yield
The Delivered Aggregated Load divided by the sum of the “grouped by” incremental drainage
areas. Units are kilograms per square kilometer per year.
Delivery Fraction (definition)
The fraction of the load leaving a reach that is not attenuated or removed by natural
processes during downstream transport to a specified downstream target reach. A delivery
fraction of 1 indicates that 100 percent of the load leaving the reach is delivered to the
downstream target.
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
Bootstrap Select
https://silviomoreto.github.io/bootstrap-select
Verision v1.0.0
Link to SPARROW REST Service:
SPARROW
National Dissolved Solids REST Services
