Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 1999
Publication Date: N/A
Technical Abstract: Soil microrelief is an important surface characteristic that modifies the force of the wind acting on the surface, thereby profoundly affecting the ability of the wind to generate dust and erode soil. Although a wide variety indexes have been proposed to describe soil surface microrelief, few relate directly to the aerodynamic effect of the wind on the surface or the abrasion process. Wind erosion prediction models use a variety of representations or models to describe the effect of surface roughness on wind erosion. Ridge height, ridge spacing, and random roughness were among the first roughness indexes used in models. We will discuss the determination and application of several roughness indexes such as the random roughness, wind erosion roughness, and chain roughness indexes. Random roughness is related to aerodynamic roughness, Zo. The effect of ridges on Zo is estimated using physical scale variables and wind profiles. The wind erosion roughness index, which relates directly to the fraction of the soil surface susceptible to abrasion, will also be discussed.