Estimates of diffuse phosphorus sources in surface waters of the United States using a spatially referenced watershed model

The statistical watershed model SPARROW (SPAtially Referenced Regression On Watershed attributes) was used to estimate the sources and transport of total phosphorus (TP) in surface waters of the United States. We calibrated the model using stream measurements of TP from 336 watersheds of mixed land...

Full description

Saved in:
Bibliographic Details
Published in:Water science and technology 2004-01, Vol.49 (3), p.1-10
Main Authors: Alexander, R B, Smith, R A, Schwarz, G E
Format: Article
Language:English
Subjects:
Agricultural land
Agriculture
Calibration
Environmental Monitoring
Freshwater
Geographic Information Systems
Hydrography
Land use
Models, Theoretical
Phosphorus
Phosphorus - analysis
Phosphorus removal
Reservoirs
River basins
Soil
Spatial data
Streams
Surface water
Transport
United States
Water Movements
Water Pollutants - analysis
Watersheds
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The statistical watershed model SPARROW (SPAtially Referenced Regression On Watershed attributes) was used to estimate the sources and transport of total phosphorus (TP) in surface waters of the United States. We calibrated the model using stream measurements of TP from 336 watersheds of mixed land use and spatial data on topography, soils, stream hydrography, and land use (agriculture, forest, shrub/grass, urban). The model explained 87% of the spatial variability in log transformed stream TP flux (kg yr(-1)). Predictions of stream yield (kg ha(-1) yr(-1)) were typically within 45% of the observed values at the monitoring sites. The model identified appreciable effects of soils, streams, and reservoirs on TP transport. The estimated aquatic rates of phosphorus removal declined with increasing stream size and rates of water flushing in reservoirs (i.e. areal hydraulic loads). A phosphorus budget for the 2.9 million km2 Mississippi River Basin provides a detailed accounting of TP delivery to streams, the removal of TP in surface waters, and the stream export of TP from major interior watersheds for sources associated with each land-use type.
ISSN:0273-1223
1996-9732
DOI:10.2166/wst.2004.0150