Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Soil Roughness for the Revised Wind Erosion Equation (Rweq):

Authors
item Saleh, Ali
item Fryrear, Donald

Submitted to: Journal of Soil and Water Conservation Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 1, 1999
Publication Date: N/A

Interpretive Summary: Dust generated from wind erosion causes significant health and economical problems. One way to control wind erosion is by roughening the soil surface. This results in creation of ridges and aggregates by which soil erosion decreases. Currently, USDA-ARS has started to compose a computer model titled, Revised Wind Erosion Equation (RWEQ)" to estimate wind erosion. This manuscript describes the procedures that followed to develop equations describing the soil surface roughness effect on wind erosion processes.

Technical Abstract: Soil surface aggregates (random roughness) and ridges (oriented roughness) can reduce soil loss by wind erosion. The soil roughness factor "K", is used to describe the effect of soil roughness on soil loss by wind. The current K in the Wind Erosion Equation (WEQ) model is a simple directional ridge roughness value without any decay by weather. This study was conducted to evaluate and modify K for use in the Revised Wind Erosion Equation (RWEQ) model. The data from past wind tunnel study was used to generate a new roughness factor (K') which includes both aggregates (random) and ridges (oriented) roughness. A function was used to predict K' at any direction perpendicular to the wind for ridged fields. Surface roughness decay functions were used to predict K' after each rainfall event using rainfall amount and a rainfall energy index (EI). Soil surface roughness measurement obtained from the chain method and ridge height and spacing can be used to estimate K' by predictive equations. A look-up table was developed to obtain K' based on soil surface roughness measurements.

Last Modified: 8/29/2014
Footer Content Back to Top of Page