An analytic model of wind-blown sand transport

Abstract

An analytic steady-state model of wind-blown sand transport is developed. The basic physical ideas are as in the current numerical models. In order to obtain explicit analytic expressions, approximations are made in all of the three subprocesses constituting the model: the trajectory model, the wind modification model, and the grain-bed collision model. Explicit formulae are derived for the transport rate and for the flux of grains from the bed into the air_ The transport rate is found to be an approximately cubic function of the friction velocity. A number of equilibrium equations are impor-tant in the theory developed in the paper. These equations are derived and thoroughly discussed in the setting of a general model of aeolian sand transport and are generally applicable_ Possible refin-ements of the theory are briefly discussed.