What causes sand dunes to form?

Sand dunes form when wind carries loose sand particles and deposits them in areas where the wind speed decreases. Over time, these particles accumulate, creating mounds or ridges. The shape and size of dunes depend on wind direction, strength, and the availability of sand. Vegetation or obstacles can stabilise dunes, preventing them from shifting. Sand dunes are common in deserts and coastal regions, showcasing the power of wind erosion and deposition.