Wind stress criteria in eolian sand transport

The linear relationship between shear velocities and wind velocities was verified from field data collected on Ecuadorian beaches during periods of sand transport. From these data a Froude number was established that expresses the relationship among wind stress, gravity acceleration, and mean grain size of sand particles. The rate of eolian sand transport by wind can be scaled by using this number. The concept was verified by available field and wind tunnel data on the subject. The equation is expressed as follows: q=K (Fr)3 where q is the rate of eolian sand transport, K is the eolian sand transport coefficient with the same dimension as q, and Fr is the Froude number.