SWAT Literature Database for Peer-Reviewed Journal Articles

Title:
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Diffuse Phosphorus Models in the United States and Europe: Their Usages, Scales, and Uncertainties 
Authors:
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Radcliffe, D.E., J. Freer and O. Schoumans 
Year:2009 
Journal:Journal of Environmental Quality 
Volume:38 
Pages:1956-1967 
Article ID: 
DOI:10.2134/jeq2008.0060 
URL (non-DOI journals): 
Model:SWAT 
Broad Application Category:review/history 
Primary Application Category:model comparison 
Secondary Application Category:phosphorus cycling/loss and transport 
Watershed Description:
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Calibration Summary:
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Validation Summary: 
General Comments: 
Abstract:Today there are many well-established computer models that are being used at diff erent spatial and temporal scales to describe water, sediment, and P transport from diff use sources. In this review, we describe how diff use P models are commonly being used in the United States and Europe, the challenge presented by diff erent temporal and spatial scales, and the uncertainty in model predictions. In the United States, for water bodies that do not meet water quality standards, a total maximum daily load (TMDL) of the pollutant of concern must be set that will restore water quality and a plan implemented to reduce the pollutant load to meet the TMDL. Models are used to estimate the current maximum daily and annual average load, to estimate the contribution from diff erent nonpoint sources, and to develop scenarios for achieving the TMDL target. In Europe, the EC-Water Framework Directive is the driving force to improve water quality and models are playing a similar role to that in the United States , but the models being used are not the same. European models are more likely to take into account leaching of P and the identifi cation of critical source areas. Scaling up to the watershed scale has led to overparameterized models that cannot be used to test hypotheses regarding nonpoint sources of P or transport processes using the monitoring data that is typically available. Th ere is a need for more parsimonious models and monitoring data that takes advantage of the technological improvements that allow nearly continuous sampling for P and sediment. Tools for measuring model uncertainty must become an integral part of models and be readily available for model users. 
Language:English 
Keywords: