The Dynamics of Sand Dunes

Abstract

Sand dunes cover 5% of Earth's land surface, and they abundantly populate river bottoms and seabeds. The subtle dynamical interplay between the granular matter and the overlaying fluid leads to rich phenomenology at different scales, from colliding grains through migrating sand dunes to slowly evolving dune fields. In this review, we survey recent developments in the literature on the dynamics of sand dunes and focus in particular on the physics and mathematics. Our discussion is organized around four central paradigms of the field: flat bed instability, single dune migration, dune–dune interactions, and dune field statistics. Besides discussing the key scientific advances, we also highlight the methodological advances in observations, experiments, and simulations that facilitated them. We conclude our review by discussing the social implications of dune dynamics, such as the interaction between dune and infrastructure, and we offer speculation on what research topics related to sand dunes might become important in the next decade.