Eolian dunes: computer simulations and attractor interpretation

Abstract

A simple computer-simulation algorithm for the transport of sand by wind produces forms resembling barchan, crescentic ridge, linear, and star natural dune classes. Sand is moved as slabs composed of many grains that are picked up at random, transported in a specified direction, and deposited: 1) with a probability that depends on the local presence or absence of sand or 2) in shadow zones in the lee of dunes. The simulated dune fields are interpreted as complex systems, with sand-dune classes being dynamical attractors of these systems. The evolution of dunes once formed becomes decoupled from the details of eolian sand transport. -Authors