Dune Formation

Abstract

Dunes are ubiquitous and exist in many forms in deserts and along coasts. They are a consequence of the wind moving sand grains by a mechanism called “saltation”. In order to describe the formation and evolution of dunes one must understand the surface flux of sand. Using the equation of motion of turbulent air in the approximation of Jackson and Hunt for gentle hills one obtains a set of equations for dune motion. These equations reproduce very well field measurements. They also allow to study in detail the collision of dunes and the stability of dune fields since their solution is many orders of magnitude faster that real time observations.