Factors controlling threshold friction velocity in semiarid and arid areas of the United States

TitleFactors controlling threshold friction velocity in semiarid and arid areas of the United States
Publication TypeJournal Article
Year of Publication1997
AuthorsMarticorena B, Bergametti G, Gillette D, Belnap J
JournalJournal of Geophysical Research
Volume102
Pagination23277-23287
Date Published1997
Accession NumberJRN00237
Keywordseolian, physical model, soil crusts, soil disturbance, threshold friction velocity, wind erosion
Abstract

A physical model was developed to explain threshold friction velocities u*t for particles of the size 60–120 µm lying on a rough surface in loose soils for semiarid and arid parts of the United States. The model corrected for the effect of momentum absorption by the nonerodible roughness. For loose or disturbed soils the most important parameter that controls u*t is the aerodynamic roughness height z0. For physical crusts damaged by wind the size of erodible crust pieces is important along with the roughness. The presence of cyanobacteriallichen soil crusts roughens the surface, and the biological fibrous growth aggregates soil particles. Only undisturbed sandy soils and disturbed soils of all types would be expected to be erodible in normal wind storms. Therefore disturbance of soils by both cattle and humans is very important in predicting wind erosion as confirmed by our measurements.

URLfiles/bibliography/JRN00237.pdf
DOI10.1029/97JD01303