NRCS Wind Erosion Equation (WEQ) Site
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National Agronomy Manual
The certified NRCS National Agronomy Manual released 04/01/03. Section 502 of this manual is the wind erosion section.
Map: Areas Where Wind Erosion Occurs on Cropland
Right click here and select "Save Target As" for a low resolution map (or left click to view)
840 x 640, tiff format, 1.5 Mb
Right click here and select "Save Target As" for a high resolution map (or left click to view)
4221 x 3217, tiff format,38.8 Mb
Wind Erosion Equation - WEQ
Recent Changes to WEQ - a slide presentation
Download the PowerPoint Presentation (1.4M) - wequpdate082302circular2.ppt
View the slide set online
C-Factor Map of the United States
Web site for C - Factor values for WEQ
Wind parameters by month for WEQ
This table contains the followinf parameters by month for various locations in the U.S.
- Prevailing Wind Erosion Direction
- Cumulative Erosive Wind Energy
Wind Parameters for WEQ for PDF format - requires Acrobat reader
windparm.wpd for Word Perfect format
windparm.doc for Microsoft Word (6./7.) format
Wind Parameters by Region and States" in EXCEL Format. Populated and maintained by Lorenz Sutherland, La Junta, CO
See the WEQ Guidance Document for instructions.
midwest.xls for IL, IN, IA, MI, MN, MO, OH, WI
west.xls for AK, AZ, CA, HI, ID, NV, NM, OR, UT, WA
northernplains.xls for CO, KS, MT,ND,NE,SD, WY
southcentral.xls for AR, LA, OK, TX
E-Tables for PDF format - requires Acrobat reader
etable.doc for Microsoft Word (97) format
etable.wpd for Word Perfect 9 format
Random Roughness Photographs
Provided by Don McCool, USDA-ARS, Pullman, Washington
These photpgraphs are also available in printable format.
Click on the hypertext below:
rough.wpd for Word Perfect 9 format
rough.pdf for PDF format (printable in a higher quality format) - requires Acrobat reader
Click on a photo to view a larger image.
Random roughness of 0.25 inches (6.4 mm).
Random roughness of 0.40 inches (10.2 mm).
Random roughness of 0.65 inches (16.5 mm).
Random roughness of 0.75 inches (19.0 mm).
Random roughness of 0.85 inches (21.6 mm).
Random roughness of 1.05 inches (26.7 mm).
Random roughness of 1.60 inches (40.6 mm).
Random roughness of 1.70 inches (43.2 mm).
Random roughness of 2.15 inches (54.6 mm).
This document was last modified on 3 January, 2008
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Wind Erosion Research