Size Distribution of Barchan Dunes by a Coarse-grained Dune Model

Abstract

Crescent sand dunes called barchan are observed in desert and on the surface of the Mars. Barchans interact with each other by collision and form barchan field. We have proposed a dune model reproducing these interactions. This model includes only saltation and avalanche as the basic sand transport processes. We have reproduced a few hundred of barchans in a numerical field and have investigated dynamics of a barchan field. We found that the size distribution of barchans is well fitted by a log-normal distribution.