Illustrative experiments of the erosion of sand and accompanying theoretical considerations

Winds in desert regions form the well-known barchan dunes. Frequently, human settlements are threatened by the migration of these dunes. But why do these dunes move? And how is dune migration in deserts connected to scour development in the vicinity of pylons in river beds or to snow cornices in alpine regions? This paper introduces the topic of particle (sand, pebble stones, snow) erosion to teachers and their students using illustrative experiments showing the most important physical phenomena. The non-costly design of the experiments also allows their implementation at schools. Finally, accompanying analyses at a secondary-school level provide an additional theoretical understanding of the experimental observations.