Why do some deflation basins have dunes on their downwind side?

Deflation basins, such as playas, often feature dunes on their downwind (leeward) side because they serve as active sources of loose sediment.12

In these arid environments, wind action erodes dry, uncemented sediments—including clays, salts, and sand—from the basin floor. As these particles are picked up by wind and transported, they are deposited on the leeward side of the basin once the wind's energy decreases or the material encounters an obstacle. In many regions, such as Australia, these leeward accumulations are specifically known as lunettes, which are crescentic dunes composed of silt and clay. In some cases, these features may even trap additional sand, contributing to the growth of larger dune systems.12