Subject: Ecs-Utah C-Factor Map

April 14, 2006

UTAH TECHNICAL GUIDE

450-IV

NOTICE UT224

SUBJECT: ECS-UTAH C-FACTOR MAP

Purpose. To transmit a recently developed C-Factor Map for Utah.

Effective Date. Available for use immediately.

General Information. A number of different C-Factor maps have been developed in the past and are currently in use in Utah. A national C-Factor map was developed in May 1987 and can be found in the National Agronomy Manual. A Utah C-Factor map was developed in April 1987 from the National Map and was made available for use by offices. Individual offices also developed county specific C-Factor maps that have been used for development of HEL lists and making HEL determinations. This new map displays the National C-Factor values for Utah and is to be used for making general wind erosion calculations. The ArcView data used to develop the map can be found on individual office servers at F:\geodata\climate\C-Factors_for_WEQ. The existing hardcopy C-Factor maps developed for use in making HEL determinations are to be maintained in all offices. Planners should use the new National C-Factor values for Utah (5/87) or the Utah Wind Erosion C-Factor values (4/87) currently found in the Utah Wind Erosion Guide (Jan. 98) when making wind erosion calculations.

Filing Instructions. The new map has already been loaded in Section I of the Electronic Field Office Technical Guide (eFOTG) and can be found in Section I\Erosion Prediction\Wind Erosion. A copy of this notice can be found in Section I under the folder “FOTG Notices and Updates” of the eFOTG. A hard copy of the map is attached with this notice. Please have planners put a copy of the map into their Utah Wind Erosion Guide (Jan. 98) with the other maps in the Section labeled “C” Value-Climatic Factor. Also have planners put a copy of this notice in the front of the Utah Wind Erosion Guide.

Contacts. For use of the map or questions on wind erosion calculations, contact Marlon Winger, Area Agronomist, at (801) 629-0580, ext. 12; Larry Young, Area Agronomist, at (435) 835-4171, ext. 22.; or Tony Beals, Area Agronomist, at (435) 637-0041, ext. 20.

/s/ M. Ron Davidson

M. RON DAVIDSON

Assistant State Conservationist -Technology

Attachment

DIST:

All FOTG Holders

Surrounding States

(210-vi-NEH, Utah Supplement April 2004) UT 4-11