NB_190_19_2 - NB 190-19-2 ECS – Request for States to Evaluate the Water Erosion Prediction Project (WEPP) and Revised Universal Soil Loss Equation, Version 2 (RUSLE2), Erosion Rates on Highly Erodible Land (HEL)
NB 190-19-2 ECS – Request for States to Evaluate the Water Erosion Prediction Project (WEPP) and Revised Universal Soil Loss Equation, Version 2 (RUSLE2), Erosion Rates on Highly Erodible Land (HEL)
National Bulletin: 190-19-2 Date: November 7, 2018
Subject: ECS – Request for States to Evaluate the Water Erosion Prediction Project (WEPP) and Revised Universal Soil Loss Equation, Version 2 (RUSLE2), Erosion Rates on Highly Erodible Land (HEL)


Action Required By:  December 14, 2018
 
Purpose.  To notify State conservationists of a required evaluation of WEPP and RUSLE2 erosion rates on HEL.           
 
Expiration Date.  March 31, 2019
 
Background.  NRCS is committed to implementing WEPP in a manner that improves the sciences of conservation delivery and best services for our customers. The transition to a new water erosion prediction tool, as has been done by NRCS several times in the past, may have both positive and negative impacts on erosion rates for highly erodible land conservation (HELC) systems. NRCS seeks additional analysis to better understand these impacts.
 
Explanation.  Additional evaluation is required of the impact of the differences between the WEPP and RUSLE2 erosion rates, specifically to determine whether there are significant differences between the models for common HELC systems across the country and in individual States.

This bulletin requires the State agronomists (or other State-designated technical specialists) to complete at least six comparisons of soil erosion rates using both the WEPP and RUSLE2. The comparisons must include two different crop rotations and ranges of conservation treatment for typical HELC systems. States with a significant amount of HEL cropland due to water erosion may be asked to run more than six comparisons to allow for a complete analysis of differences in erosion rates between the WEPP and RUSLE2. The task will take approximately 3 hours to complete. Please refer to the attachment for the evaluation instructions.

The results of this evaluation will be used nationally to analyze the impacts of the new WEPP tool on erosion rates for common HELC systems, and locally during State discussions with landowners and stakeholders.

Please submit the results of the evaluation to Mike Kucera, acting national erosion specialist, at Michael.Kucera@lin.usda.gov by December 14, 2018.
 
Contact.  If you have questions, please contact Mike Kucera or Dana Ashford-Kornburger, Acting Director, Ecological Sciences Division, at Dana.Ashford@wdc.usda.gov.
 
 

 /s/

DIANE E. GELBURD
Acting Deputy Chief for Science and Technology



ASTOR BOOZER
Regional Conservationist, West



TERRELL A. ERICKSON
Acting Regional Conservationist, Northeast



XAVIER MONTOYA
Acting Regional Conservationist, Southeast



KEVIN WICKEY
Regional Conservationist, Central
 
Attachment A - Evaluation Instructions 
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