Topographies created by Wind Erosion
1. Kshatrak- Due to the action of air in the desert regions, many rocks appear like a plant called ‘Kshatrak’. This type of texture of rocks is called Chhatrak. There is a canopy of granite near Jodhpur (Rajasthan), which is called Nata in the Sahara desert. These are formed by natural wind erosion, channeling, and excavation. A flat rocky block rests on a thin pillar at its base. This natural texture is also called beetle.
2. Geogen- Where soft layers are covered by hard layers and when the upper hard layer is cut by continuous gusts of wind, the soft shell below is cut quickly. Sometimes the rock base is eroded and the entire rock becomes crooked. These ridges are called Jiugen.
- Describe the Principle of Plate Tectonics.
- Give an Analytical Description of the Landforms Formed by River Erosion.
- Classify the Rocks and Describe their Composition, Characteristics, and Usage.
- Describe the Concept of Normal Erosion Cycle Propounded by Davis.
3. Yardang – When the air always moves in the same direction and the strips of hard and soft rocks are located parallel to the flowing air, then the shape and form of the visible land become strange and the form of the flat rock block becomes irregular like ridge and groove. It goes and in course of time, the whole region appears like rocky ribs. Like pillars, the visible central part is more cut and the unevenly shaped vertical sides are called yardangs in the deserts of Central Asia.
4. Dvipabha Giri- Due to the collective work of air and water, flat plains are presently based on rocks, and drains are formed on the surface. In such regions, here and there rocks remain standing like mounds. They are found in the desert of Rajasthan, they are called Dweepam Giri.
5. Trikotika – The upper part of the rocky pieces lying in the deserts gets smoothed by the blow of air or they get scratched. These rock pieces are overturned or become sharp-edged Nagin’s initiative when the wind direction changes. Different types of carvings are found on these and they are usually three-sided boulders. These types of rocky pieces are called Trikotika or Nepal. They are mostly found in Sahara.
6. Rock pillars are also formed by the combined effect of air and water on the top of which circular rocks are situated on the earth. These are called earth pillars.
7. Rock-lattice Due to the blow of the dust particles flying in the air, the soft parts of the soft and hard rocks located on the way are cut off and as a result that rock becomes like a net. This is called rock lattice. Reticulated rocks of a sand layer are found in Raki mountain. Due to rapid wind erosion of a wide area of sandstone, the rock powder is scattered and a rocky desert of rock fragments is formed.
Loose particles are transported from the ground level by the wind. The particles of sand or dust are carried by blowing from one place to another. Light and microscopic particles hang in the air and their transport takes place in this condition. Heavy particles of large size keep rolling on the surface, but particles of medium size and weight sometimes do. They are transported by flying and sometimes rolling in the air. These actions depend on the velocity of the wind.
Air deposition operations
The particles of sand or dust blew by the wind get collected on the ground when the wind slows down. Congestion occurs when there is an obstruction in the passage of air. Most of the deposits are permanent. These are called Vatong • Deposits. It is named after the wind god Aeolus. In regions where erosion is more, rocky deserts are formed, and where deposition is more, deserts of sand and loess are formed. Their texture depends on the composition of the parent rock and the gradual arrangement of the deposited materials.
Dunes are formed by the accumulation of sand. For their creation, an abundance of sand, a place for sand accumulation, high velocity of air, and obstruction in the airway are necessary. An infinite amount of sand is found in deserts, river beds, and sea coasts, hence there is an abundance of sandstone stupas in these regions.
When the surface of dunes is disorganized, they are called dunes. Valuka-ticha of 30 m to 90 m in height are found in the deserts. One-third to one-fourth of the area of each desert is covered in dunes. The country with the most dunes in the world is Arabia, where dunes cover one-third of the land surface. Only the ninth part of the Sahara desert is covered with sand and the remaining part is scattered with rock blocks, air-formed stone blocks, and bedrock.
If considered from the point of view of texture, dunes have a long and convex slope towards the windward side and a steep and concave slope towards the windward side. In this, a cave-like formation is formed in the sand mass due to the wind vortex in the direction away from the wind, which is also called the ship face.
Slight zigzag lines of sand are visible on the leeward side of the slope and gradually its expansion and size increase because on their leeward side the sand particles are spread on both sides of the top by the vortex of air and the sand- Shape of the dunes becomes crescent-shaped and elongated. If the wind blows from all sides, the shape of the mound becomes round. Thus, in different circumstances, the shape of the dunes is round at some places, crescent-shaped at some places, and flat at some places.
1. Longitudinal Sand-Tivwa- These dunes are formed in both desert and desert-type areas. They originate from a great amount of sand and a lack of vegetation. Aggregation range of sand particles in it vertically like friendly. These series are usually parallel and present the shape of the tooth. In the desert of Saha, it is called Seef. This type of dune is formed in the direction of the wind. Air prevails in it. Their existence is possible due to the modification of crooked and different dunes.
2. Transverse sand-dune- their expansion is perpendicular to the wind direction. They are formed by light air in the deep sandy country. They are also often found on the banks of rivers and lakes. There is a small strip between the parallel rows of dunes, in which light whirlpools of air are created, which keep deepening the central part by blowing fine sand.
3. Parabolic sand-dune- In this type of sand-dune, there is a gentle slope on the windward slope, or as a result friction pits are formed on it. Wind – The windward slope is steeper where the sand particles are deposited. Windward dunes of coastal areas are examples of this.