A continuous model for Aeolian sand dunes and its application to barchan dune fields and vegetated “parabolic” dunes

The existence of a minimal size for Aeolian dunes of about 10m long, and thus, the impossibility of generate them in wind tunnel experiments, has led to an enormous emphasis in numerical simulations as the simplest, and sometimes the only, tool to get insight into the dune emergence and evolution under controlled conditions.

In this talk, I’m going to present a continuous sand transport model developed in successive contributions by the H.J. Herrmann’s group, and I’ll focus on two main applications: first, the emergence of barchan dune fields from a “beach” as a result of the coupling of a longitudinal and transversal instability, and second, the inactivation of fully developed crescent dunes. By including vegetation into the model, we were able to study the emergence of inactive parabolic dunes from active barchans, and hence, to uncover the mechanisms underlying dune inactivation induced by the vegetation growth.