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.

 M_190.pdf

Map: Areas Where Wind Erosion Occurs on Cropland

Wind Erosion Map
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
  or
 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
  - Preponderance
  - Erosivity
  - 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

 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).



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This document was last modified on 3 January, 2008 .
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