  Our aim in this note is to introduce and study a mathematical model for the
description of traveling sand dunes. We use surface flow process of sand under
the effect of wind and gravity. We model this phenomena by a non linear
diffusion-transport equation coupling the effect of transportation of sand due
to the wind and the avalanches due to the gravity and the repose angle. The
avalanche flow is governed by the evolution surface model and we use a nonlocal
term to handle the transport of sand face to the wind.
