Fixed Dune

Fixed dunes are a type of sand dune that remain relatively stationary over time. These dunes are covered in vegetation and are formed by the interaction between sandstorms and plants. They are typically found in transitional zones between deserts and the Gobi. When sand carried by the wind comes across vegetation in the Gobi, its progress is obstructed. This obstruction causes certain grains of sand to settle on either the leeward or windward side of the vegetation, forming irregular sand structures. With continued sand deposition on the roots and sides of plants, these formations grow into mound-like structures known as fixed dunes. The height and diameter of these dunes are dependent on the height of the vegetation and the size of the shrubs. Typically, these dunes do not exceed the height of the surrounding vegetation, and very few plants grow on the windward side. In the Yardang Geoarea, the fixed dunes can reach a height of 1.7 meters. The surface of these dunes is covered with Nitraria tangutorum Bobr., while low-lying areas are home to reeds, Cynomorium songaricum, and other plants.