Paper No. JAWRA-11-0079-P of the Journal of the American Water Resources Association (JAWRA). Discussions are open until six months from print publication.
Watershed Regressions for Pesticides (warp) Models for Predicting Atrazine Concentrations in Corn Belt Streams1
Article first published online: 31 MAY 2012
© 2012 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA
JAWRA Journal of the American Water Resources Association
Volume 48, Issue 5, pages 970–986, October 2012
How to Cite
Stone, W. W. and Gilliom, R. J. (2012), Watershed Regressions for Pesticides (warp) Models for Predicting Atrazine Concentrations in Corn Belt Streams. JAWRA Journal of the American Water Resources Association, 48: 970–986. doi: 10.1111/j.1752-1688.2012.00661.x
- Issue published online: 1 OCT 2012
- Article first published online: 31 MAY 2012
- Received June 16, 2011; accepted March 12, 2012
- nonpoint source pollution;
- water quality;
- regression analysis
Stone, Wesley W. and Robert J. Gilliom, 2012. Watershed Regressions for Pesticides (WARP) Models for Predicting Atrazine Concentrations in Corn Belt Streams. Journal of the American Water Resources Association (JAWRA) 48(5): 970-986. DOI: 10.1111/j.1752-1688.2012.00661.x
Abstract: Watershed Regressions for Pesticides (WARP) models, previously developed for atrazine at the national scale, are improved for application to the United States (U.S.) Corn Belt region by developing region-specific models that include watershed characteristics that are influential in predicting atrazine concentration statistics within the Corn Belt. WARP models for the Corn Belt (WARP-CB) were developed for annual maximum moving-average (14-, 21-, 30-, 60-, and 90-day durations) and annual 95th-percentile atrazine concentrations in streams of the Corn Belt region. The WARP-CB models accounted for 53 to 62% of the variability in the various concentration statistics among the model-development sites. Model predictions were within a factor of 5 of the observed concentration statistic for over 90% of the model-development sites. The WARP-CB residuals and uncertainty are lower than those of the National WARP model for the same sites. Although atrazine-use intensity is the most important explanatory variable in the National WARP models, it is not a significant variable in the WARP-CB models. The WARP-CB models provide improved predictions for Corn Belt streams draining watersheds with atrazine-use intensities of 17 kg/km2 of watershed area or greater.