Agricultural and Biosystems Engineering Publications
Campus Units
Agricultural and Biosystems Engineering, Agronomy
Document Type
Article
Publication Version
Published Version
Publication Date
2017
Journal or Book Title
Journal of Environmental Quality
Volume
46
First Page
1349
Last Page
1356
Research Focus Area(s)
Land and Water Resources Engineering
DOI
10.2134/jeq2016.07.0254
Abstract
Phosphorus (P) Index assessment requires independent estimates of long-term average annual P loss from fields, representing multiple climatic scenarios, management practices, and landscape positions. Because currently available measured data are insufficient to evaluate P Index performance, calibrated and validated process-based models have been proposed as tools to generate the required data. The objectives of this research were to develop a regional parameterization for the Agricultural Policy Environmental eXtender (APEX) model to estimate edge-of-field runoff, sediment, and P losses in restricted-layer soils of Missouri and Kansas and to assess the performance of this parameterization using monitoring data from multiple sites in this region. Five site-specific calibrated models (SSCM) from within the region were used to develop a regionally calibrated model (RCM), which was further calibrated and validated with measured data. Performance of the RCM was similar to that of the SSCMs for runoff simulation and had Nash–Sutcliffe efficiency (NSE) > 0.72 and absolute percent bias (|PBIAS|) < 18% for both calibration and validation. The RCM could not simulate sediment loss (NSE < 0, |PBIAS| > 90%) and was particularly ineffective at simulating sediment loss from locations with small sediment loads. The RCM had acceptable performance for simulation of total P loss (NSE > 0.74, |PBIAS| < 30%) but underperformed the SSCMs. Total P-loss estimates should be used with caution due to poor simulation of sediment loss. Although we did not attain our goal of a robust regional parameterization of APEX for estimating sediment and total P losses, runoff estimates with the RCM were acceptable for P Index evaluation.
Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
File Format
application/pdf
Recommended Citation
Nelson, Nathan O.; Baffaut, Claire; Lory, John A.; Senaviratne, G.M.M.M. Anomaa; Bhandari, Ammar B.; Udawatta, Ranjith P.; Sweeney, Daniel W.; Helmers, Matthew J.; Van Liew, Mike W.; Mallarino, Antonio P.; and Wortmann, Charles S., "Multisite Evaluation of APEX for Water Quality: II. Regional Parameterization" (2017). Agricultural and Biosystems Engineering Publications. 879.
https://lib.dr.iastate.edu/abe_eng_pubs/879
Included in
Agriculture Commons, Bioresource and Agricultural Engineering Commons, Environmental Indicators and Impact Assessment Commons, Environmental Monitoring Commons, Natural Resources Management and Policy Commons, Sustainability Commons, Water Resource Management Commons
Comments
This article is published as Nelson, Nathan O., Claire Baffaut, John A. Lory, G. M. M. M. Anomaa Senaviratne, Ammar B. Bhandari, Ranjith P. Udawatta, Daniel W. Sweeney et al. "Multisite evaluation of APEX for water quality: II. Regional parameterization." Journal of Environmental Quality 46, no. 6 (2017): 1349-1356. DOI: 10.2134/jeq2016.07.0254. Posted with permission.