The difference between dunes and dunes.

The wind can be a great builder and create amazing relief in the form of dunes and dunes on the surface of the Earth. These formations arise according to the same principle. But there is also the difference between dunes and dunes.

Definition

Dune - the form of a towering relief; a mobile sandy hill, usually not fixed by vegetation. The formation of a dune, like dunes, begins with the fact that the wind blowing in the sandy zone bumps into a stone, a piece of wood or other object. Grains of sand begin to accumulate behind this obstacle. A small mound is formed, which over time becomes denser and grows. Gradually the embankment turns into a crescent dune. Many such formations merge into continuous long chains.

Dunes

Dune is also formed gradually, under the influence of the wind. It is a sandy rise that is often covered with vegetation. Dunes and dunes can grow up to 100 m, and sometimes they are much higher than this level.

Dunes

Comparison

The determining factor that makes the difference between dunes and dunes is the location of the sandy mountains. Formations in the desert are usually called dunes, and sand hills on other parts of the earth's surface are called dunes.

It is the location of the sandy formations that determines the presence or absence of vegetation on them. If the dunes arise in an arid environment, then the dunes rise on the sea coasts, near lakes, rivers, in the steppe zone, that is, where there is water necessary for the existence of representatives of the flora.

Vegetation often settles on the “horns” (flanks) of dunes because it is easier for it to break through where the sand is lower. Thus, the edges of the dune are fixed, and its center moves under the influence of the wind. As a result, the dune meets the wind with the concave side of its central part. In the case of a dune, which is not fixed by anything, it is the sides that turn out to be weak, therefore they are the most mobile, and the central part faces the wind with its convex side.

The wind is capable of moving entire sandy hills of one and the other type. But what is the difference between dunes and dunes in this case? Here again, vegetation plays a role. The dunes free from it can move through the desert much faster - up to hundreds of meters per year. Dunes during the same time are able to overcome up to two tens of meters.

Table

Dunes Dunes
Formed in the desertFormed outside the desert
Generally no vegetationCan germinate
Facing the wind with the convex partFacing the wind with the concave part
Moving fasterMoving slower
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