The dune size distribution and scaling relations of barchan dune fields

TL;DR

This paper investigates the size distribution and spatial arrangement of barchan dunes in Moroccan fields, proposing an analytical model that explains their collective behavior through dune interactions and sand flux dynamics.

Contribution

It introduces a mean-field analytical model linking dune collisions, sand flux, and size distribution, revealing scaling relations in barchan dune fields.

Findings

Dunes tend to distribute uniformly in space.

A unique size distribution function describes the dunes.

The model predicts a scaling relation between dune spacing and size moments.

Abstract

Barchan dunes emerge as a collective phenomena involving the generation of thousands of them in so called barchan dune fields. By measuring the size and position of dunes in Moroccan barchan dune fields, we find that these dunes tend to distribute uniformly in space and follow an unique size distribution function. We introduce an analyticalmean-field approach to show that this empirical size distribution emerges from the interplay of dune collisions and sand flux balance, the two simplest mechanisms for size selection. The analytical model also predicts a scaling relation between the fundamental macroscopic properties characterizing a dune field, namely the inter-dune spacing and the first and second moments of the dune size distribution.