Surface Water Models

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Scientists in the Surface Water Protection Program (SWPP), California Department of Pesticide Regulation (CDPR) frequently use simulation models for pesticide risk assessments in product registration evaluation, post-use monitoring, and data analysis. Listed below are selected SWPP models with technical reports and user's manual.

SWMP (Surface Water Monitoring Prioritization Model) Yuzhou Luo, 2015

SWMP model is developed to prioritize pesticides for surface water monitoring in agricultural and urban areas of California. For the generation of monitoring priority lists of pesticide ingredients and their degradates, the model incorporates pesticide use and toxicity data, as well as chemical properties, monitoring results, and application information. Advanced options are also provided in the model for monitoring prioritization at various spatial and temporal scales, with user-defined months, years, counties, and watersheds.

• Video
• Executable and supporting database (.zip compressed file), version 3.0
• User's manual, PDF
• Technical Reports
  • Analysis Report, PDF. Yuzhou Luo, Xin Deng, Robert Budd, Keith Starner, Michael Ensminger. 2013. May 28, 2013.
  • Analysis Memo, PDF. Yuzhou Luo, Michael Ensminger, Robert Budd, Xin Deng, and April DaSilva, 2014. II: Refined Priority List.
  • Analysis Report, PDF. Yuzhou Luo and Xin Deng, 2015. III: Watershed - Based Prioritization.
  • Analysis Memo, PDF. Yuzhou Luo, Michael Ensminger, Robert Budd, Dan Wang, Xin Deng 2017. Methodology for prioritizing areas of interest for surface water monitoring of pesticides in urban receiving waters of California.

PREM (Pesticide Registration Evaluation Model)

The Pesticide Registration Evaluation Model (PREM) is used by DPR's Surface Water Protection Program (SWPP) to evaluate aquatic impacts of pesticide products submitted to California for registration. PREM assesses potential risks of products to adversely affect aquatic and benthic organisms thereby allowing SWPP to protect the environment & human health. The earliest version of PREM was released in 2012. It continues to evolve to better fit California conditions. New versions of the model are developed to incorporate major improvements in modeling capabilities. All posted versions are summarized as follows (please note that version 1 was only for internal development and test only and thus not listed below):

• Version 2: the initial modeling framework was developed with a two-stage evaluation procedure.
  • Methodology for Initial Screening, PDF. Yuzhou Luo and Xin Deng. January 26, 2012
  • Methodology for Refined Modeling, PDF. Yuzhou Luo and Xin Deng. January 26, 2012
  • Notice to California Registrants 2012-02, PDF. Evaluation for Impacts to California Surface Waters. February 7, 2012
• Version 3: the modeling capability for evaluating urban pesticide uses was added.
  • Methodology for Evaluating Urban Pesticide Uses, PDF. Yuzhou Luo. February 28, 2014.
  • Model User Manual, PDF. Yuzhou Luo and Nan Singhasemanon. October 2, 2014.
  • Notice to California Registrants 2015-02, PDF. Revision to the DPR's Evaluation for Impacts to California Surface Waters: Improved Urban Evaluation (Supersedes CA Notice 2012-02), February 24, 2015
• Version 5: integration of degradate evaluation, updated decision-making process, and other model improvements.
  • Model User Manual Version 5, PDF. Yuzhou Luo, Nan Singhasemanon, Jennifer Teerlink. December 9, 2019
  • Methodology for Screening Pesticide Products with High Exposure Potentials to Marine/Estuarine Organisms, PDF (557 kb). Yina Xie and Yuzhou Luo. March 25, 2016
  • Evaluation methodology for pesticide degradates, PDF. Yuzhou Luo, Nan Singhasemanon, and Xin Deng. May 3, 2016.
  • Methodology for Evaluating Pesticides for Surface Water Protection, PREM Version 5 Updates, PDF. Yuzhou Luo. March 6, 2020.
• Version 6 (current version): integration of new model improvements.
  • Executable and supporting data (.zip compressed file), version 6.0
  • Report 293, PDF. Yina Xie. 2016. Developing a California-Based Receiving Waterbody Model for Pesticide Product Registration Evaluation: Review of Model Theory.
  • Modeling pesticide removal efficiency by vegetative filter strip under PWC scenarios, PDF. Yuzhou Luo.
  • Methodology for Evaluating Pesticides for Surface Water Protection: Evaluation on Down-the-Drain Products, PDF. Yina Xie and Yuzhou Luo.
  • Validating PREM performance for modeling outdoor uses of pyrethroids in residential areas of California, PDF. Yuzhou Luo.
  • Methodology for Evaluating Pesticides for Surface Water Protection: PREM version 6 updates, PDF. Yuzhou Luo, Yina Xie, and Xin Deng. April 10, 2024.
  • Model User Manual Version 6, PDF. Yuzhou Luo, Yina Xie, Xin Deng, Anson Main. April 10, 2024,.

Additional information related to water models:

• Methodology for evaluating pesticides for surface water protection: Spatial modeling for aquatic exposure assessment, PDF. Yuzhou Luo.

For content questions, contact:
Yuzhou Luo, Ph.D.
1001 I Street, P.O. Box 4015
Sacramento, CA 95812-4015
Phone: (916) 445-2090
E-mail: Yuzhou.Luo@cdpr.ca.gov