NRCS Wind Erosion Equation (WEQ) Site

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

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

C factor Less than 3 shape.zip Shape files for C - Factor less than 3 for WEQ
C factor Line shape.zip Shape files for C - Factor values for WEQ
C Factor Map, CA, NV.pdf C - Factor Map of CA and NV for WEQ
C Factor Map, CO.pdf C - Factor Map of CO for WEQ
WA, ID, OR.pdf C - Factor Map of WA, ID, and OR 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

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.pdf for PDF format (printable in a higher quality format) - requires Acrobat reader

Click on a photo to view a larger image.