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Updated: Jul 11, 2026
06:42
Measuring Phosphorus Release in Laboratory Microcosms for Water Quality Assessment
Published on: July 22, 2019
Modeling phosphorus in the upper Etowah River basin: identifying sources under uncertainty
Z Lin1, D E Radcliffe, M B Beck
1BCI Engineers & Scientists, Inc., Lakel, FL 33803, USA. zlin@sjrwmd.com
Summary
The Uniform Covering by Probabilistic Rejection (UCPR) algorithm and SWAT model identified phosphorus (P) sources in Georgia's Etowah River. Point sources, pastures, and forests are major P contributors.
Area of Science:
- Environmental Science
- Water Resource Management
- Hydrology
Background:
- Phosphorus (P) loading is a critical issue in river basins, impacting water quality.
- Identifying P sources is essential for effective watershed management and pollution control.
Purpose of the Study:
- To apply the Uniform Covering by Probabilistic Rejection (UCPR) algorithm with the Soil and Water Assessment Tool (SWAT) model to pinpoint P loads in the upper Etowah River basin (UERB).
- To evaluate P contributions from point and nonpoint sources, including agricultural pastures and forests.
Main Methods:
- Utilized the UCPR algorithm in conjunction with the SWAT model for P load identification.
- Compared mean absolute error (MAE) and root mean square error (RMSE) as search criteria, favoring MAE for scarce water quality data.
Main Results:
- The UCPR method estimated an undocumented P load of approximately 43 kg/d from point sources in the UERB.
- Point sources (documented and undocumented), poultry/beef pastures, and forests were identified as the top three P contributors.
- These sources accounted for an average of 36.4%, 31.7%, and 17.2% of the total P load, respectively, between 1992-1996.
Conclusions:
- The UCPR algorithm, coupled with SWAT, provides a viable method for identifying P sources in river basins, even with limited data.
- Point sources and agricultural activities are significant drivers of P pollution in the UERB.
- Further research may be needed to refine the estimation of P loads from specific agricultural practices like broiler litter application.
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