how dunes get formed in desert?

Answer 1

In physical geography, a dune is a hill of sand built by eolian processes. Dunes are subject to different forms and sizes based on their interaction with the wind. The "valley" or trough between dunes is called a slack. A "dune field" is an area covered by extensive sand dunes. Large dune fields are known as ergs.

Some areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach. In most such cases the dunes are important in protecting the land against potential ravages by storm waves from the sea. Although the most widely distributed dunes are those associated with coastal regions, the largest complexes of dunes are found inland in dry regions and associated with ancient lake or sea beds.

Dunes also form under the action of water flow (alluvial processes), on sand or gravel beds of rivers, estuaries and the sea-bed.

Eolian (or aeolian or æolian) processes pertain to the activity of the winds and more specifically, to the winds' ability to shape the surface of the Earth and other planets. Winds may erode, transport, and deposit materials, and are effective agents in regions with sparse vegetation and a large supply of unconsolidated sediments. Although water is much more powerful than wind, æolian processes are important in arid environments such as deserts.

Answer 2

Consider the problem of winds blowing sand across a flat surface. Sand is deposited whenever local wind conditions is insufficient to keep it aloft. Ideally, sand is deposited uniformly across the surface. But suppose the "symmetry" is broken, and some sand collects more in some places than others. That sets up uneven conditions for more sand to be deposited where the greater accretions are occurring, thus accelrating the process of forming an uneven deposition of sand across the surface. This is how sand dunes form. Once they are formed, they can have surprisingly long lifetimes, as sand blown from one side of the dune is frequently deposited on the next side, thereby causing sand dune drift. Sand dunes are more likely to occur when there is a prevailing wind direction, but irregular sand dunes can form even where there isn't.

Answer 3

Just like the wind forms waves on the ocean...

Answer 4

Blown by the wind

Answer 5

In simple terms it's caused by wind.

Answer 6

It's the placer effect of gravity.

wind yes but also rain, sunlight, specific gravity, temperature all contribute to the placer effects of gravity over time.

Ob1

Answer 7

by the wind