Eolian relief and its basic forms. The dunes are ...

The relief of our planet is tremendously diverse. This article will deal with dunes. How and where are they formed? And what are these picturesque natural formations?

Aeolian relief. The dunes are ...

Geography studies not only countries and cities. In the sphere of interests of this science is also the relief - the totality of all irregularities on the surface of the planet Earth. Geomorphology (a special section of geography) studies its basic forms, genesis, and distribution.

The relief is different. In the process of its formation, practically all the forces and phenomena observed in our world are involved. Thus, some form of relief arises under the influence of the internal energy of the Earth, while others are formed by permanent or temporary watercourses. But the dunes are nothing more than a classic product of wind work.

The dune is one of the forms of the so-called eolian relief. This term comes from the name of the ancient Greek character, the demigod Eola. According to myths, he is the chief lord of the winds.

Eolian processes are accompanied by the transfer of fine sand, clay or dust particles to specific distances, their accumulation and distribution over the earth's surface. The most suitable conditions for these processes are in the zone of deserts and semi-deserts, where the deposit material is not fixed by the root systems of plants.

The main forms of eolian relief are barkhans and dunes. These are sandy natural formations, which differ from each other in shape, size, and also the place of their formation. Barkhans are formed exclusively in deserts, have a crescent shape and reach a height of 60-70 meters. In turn, the dunes are a smaller form of relief, widely found along the shores of lakes, seas and large rivers. More details about them will go further.

Dunes - what is this? Formation and main types of dunes

If there are shrubs, boulders, remains of walls on the seashore or any large pond, then this is an excellent precondition for the formation of the described relief shape. What are dunes? This, to put it in simple terms, the sand hills created by the wind. Tiny grains of sand accumulate over time near some obstacle. So dunes are formed, the shape of which depends on the winds of a particular locality in the plan.

The heights of the dunes, as a rule, range from 20 to 40 meters. In some parts of the planet there are real sand giants up to 100-150 meters (for example, on the shores of the Bay of Biscay). The windward slope is usually flat (about 10-15 degrees), and the leeward slope is approximately twice as steep. Single dunes are rare. Most often they form elongated chains of hills of sand.

Depending on the shape of the dunes are divided into three types:

• Horseshoe shaped (formed when the wind blows around the same year in one direction);
• Transverse (formed in places with a lot of sand);
• Star (the most picturesque dunes formed in places where the wind often changes its direction).

Movement of dunes

These amazing natural formations are also moving! This happens, again, under the influence of the wind. He rolls sand from one slope to the other, causing the dunes to change their position in space. Speed of movement at them is insignificant - about 20-30 meters for a year.

It is important to note that the movement of the dunes is a real problem. After wandering sand hills destroy crops in the fields, fall asleep roads, pastures and even whole villages. People try to fight this phenomenon by fixing the sands. For this, grasses, trees and shrubs are planted on the windward slopes of dunes and barkhans. With their root systems, the plants retain grains of sand from further "travel".

The most famous dunes of the planet

France, Namibia, Russia, Wales and Australia - which unites all these countries? That's right - dunes! Each of them has its own "wonder from the sand". Let's talk about them in order.

Dune Pila (France) is the highest in Europe. It is located on the shores of the Arcachon Bay of the Atlantic and has a height of 130 meters. This place is very popular among tourists. It is interesting that every year the saw sinks a few meters into the depths of a century old pine forest.

"Big Daddy" (Namibia) - the highest dune of the Namib desert (304 meters). The conquest of this orange-red sandy mountain is a must for any tourist who came here.

The height of Efa (Russia) is an interesting natural object located on the Curonian Spit, in the Kaliningrad region. The maximum height of this dune is 64 meters. A special hiking trail leads to its summit.

Dune Inislas (Wales) - one of the most beautiful places in this part of Britain. And Inislas does not look lifeless, it is almost completely covered with beautiful herbs and wildflowers. In addition, the dune is extremely mobile and constantly changes its shape.

Mount Tempest (Australia) is considered the second tallest dune in the world (285 meters). It is located in the north-east of the country, not far from the city of Brisbane. Dune attracts the attention not only of travelers, but also of professional photographers, since it has a wonderful view of the Australian coast from its top.

Conclusion

So, dunes are a form of relief of aeolian origin. That is, its main "builder" and "sculptor" is the wind. Dunes are formed on the shores of large reservoirs, differ in their small size and mobility.