Give an Analytical Description of the Landforms Formed by River Erosion.

Landforms Formed by River Erosion

(1) Water Falls- If the layers of hard and soft rocks are lying alternately, then rocky platforms are formed in the valley. If the hard folds are located along the soft folds and are slightly inclined towards the flow of the river, then a series of falls are formed in the river valley. Within the flat soft rocky layers, if any vertical rock is found, then falls are formed in the valley. When the hard rock layers lie transversely over the soft rock layers, then also a waterfall is formed in the river valley, but due to the breaking of the soft rocks below, the upper hard rocks also break and the waterfall moves backward. There is a possibility of such falls ending over time.


(2) Formation of depression trough- When the layers of hard rocks remain in a transverse position above the layers of soft rocks, then the soft rocks are cut and a depression trough is formed in it. The water of this kund soaks the soft rocks by bouncing and in course of time, the soft rocks fall and get washed away. When these rocks are washed away, the upper rocks fall due to their weight, and the waterfall moves backward. Over time, the waterfall ends when the hard rocks are destroyed. When hard rocks stand upright, they do not break and the waterfall becomes permanent.

(3) Stepped Falls – When water falls in many steps along the side of a terraced wall, they are called Stepped Falls. When a large body of water flows over hard rocks, due to which the rock is not visible from above, it is called a waterfall. Madhya Pradesh is full of waterfalls. There is a waterfall named ‘Kapildhara’ in Amarkantak, 266 km from Rewa in the Narmada river. Adjacent to this beautiful mesmerizing fall was Kapil Muni’s penance. The second fall in Narmada is Dugdhdhara. It is formed on the plateau inside the Vindhya ledge.

(4) River valley plain: Rivers start cutting the lower part and sides of their bed. And also deposit the transported material. Large plains are formed by this fertilization, it is called the river-valley plain. In this condition, deposition is more than erosion in the valley. The depth of the valley gradually decreases. The condition of flood becomes present in the river. It is called the slope of the river valley because such bends are found in the Mind river. In the initial stage, the valley of the Visarpo river is narrow and the slip occurs in an underdeveloped state. They have less complexity. Gradually the valley also widens and the turns become complicated.

(5) Formation of the river bend and Cchadan lake The water stream in the course of the river collides with the concave bank of the valley. As a result, that bank gets cut and there is an obstruction in the flow of the river. The flow tends to divert due to obstruction. Erosion materials start accumulating on the north bank. The concave edge appears to be erect and the convex edge is blunt. The depth of the river is also greater towards the concave bank and gradually decreases towards the convex bank. For this reason, the steep banks keep on eroding and less sand is deposited on the banks, due to which the bend in the flow of the river increases. In this way, the slip increases so much that the shape of the river becomes completely circular. In this condition, the rivers leave their course at the time of flood and start flowing by cutting the part near the bend. This straight flow path remains even after the flood. In such a condition, the curved part takes the form of a lake which is called a Chain. Many such lakes are found in the plains of the river Ganga.

(6) The velocity of the river is high in the middle of the delta-river stream. Therefore, the water of that part enters the sea to a greater extent. In this way, the depression gets accumulated in the shape of a district far away in the sea, but due to the slowness of the water on the shore, it ends at the confluence of the sea and the depression gets accumulated there. Gradually this sea plain becomes above the water, but the water of the river becomes relaxed. And it flows in many streams and goes to the sea. Thus the letters of the Greek language are at the mouths of the rivers A triangular plain is formed in the shape of a delta. They are given the name of the delta. The delta plain slopes towards the sea. The following conditions are necessary for the formation of a delta-

(a) The lower valley of the river should be wider, in which the stream of the river becomes completely relaxed while reaching the mouth.

(b) There should not be any lake in the course of the river because the sediments of the river get collected in the lakes and there is no sediment left in the rivers for delta formation.

(c) The mouth of the river should be free from tides and sea currents, otherwise, the depression will be far away. Till it flows into the sea and the delta is not formed.

(d) The river should originate from high mountains and their tributaries should also be high so that sufficient river load can be given and a delta can be formed.

There are three stages in the formation of a delta. As a result of deposition in the first stage, many water distributaries of the river are formed. Bhujihva becomes Radhika and Anoop. In the second stage, an oops become depressed and becomes marshes. In the third stage, plants grow in the delta, and swamps disappear. The delta becomes higher and part of the delta becomes dry land.

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