Which landforms are formed by lateral erosion

The bends of sinous rivers have been named meanders on the basis of Meander River of Asia Minor Turkey because it flows through numerous bends. This side of the meander belt is also called as cliff-slope side. The other side of the meander belt is characterized by convex slope which receives deposition mostly of sands and gravels but sometimes alluvium is also deposited. The shape of meander is usually semi-circular but sometimes it is also circular.

The length of a meander belt can be found out on the basis of the channel width because meander belt is usually about 15 to 18 times the width of bankfull channel. It may be pointed out that the meandering is a natural process which is governed by a number of environmental factors viz.

All streams meander in all types of terrains e. If the value ranges between 1 and 1. The gradient of highly meandering streams ranges between 20 cm to 10 m per kilometre. All of the alluvial streams of the Northern Plains of India have developed meandering courses. The Gomti river Uttar Pradesh is a typical example of highly meandering stream of alluvial plains because of the fact that its channel gradient is very low 9 cm per kilometre between Lucknow and Sultanpur.

Meanders are divided into two major types on the basis of the nature of fluvial erosion e. The wavy meanders are very simple in plan fig. Such meanders have been developed by the major streams in the Himalayas.

The horse-shoe types of meanders are those in which the beds are highly curved fig. The meanders developed during first cycle of erosion by a stream are called simple meanders. These are formed by lateral erosion. There are certain necessary conditions for the development of simple meanders, a Over-loaded streams cannot form meanders because their total power is spent in the transportation of huge amount of sediments.

Such rivers are always engaged in depositional activity. The streams in youthful stage are also not capable of forming meanders because they are actively engaged in incising their valleys through down-cutting and related valley deepening.

The most ideal conditions required for development of meanders are alluvial plains, gentle slope, sufficient amount of precipitation and general absence of vegetation. A minor obstruction in the free flow of the streams in flood plains diverts their courses from straight course and thus the process of meander formation begins with the initiation of very minor bends in the longitudinal courses of the alluvial streams formation of wavy meanders, fig.

The channel currents strike against the concave side of the open meander bends and cut the loose geomaterials alluvium and thus there is continuous sharpening of meander bends resulting into high degree of curvature of meander loops formation of horse-shoe type of meander, fig. It may be pointed out that simple meanders develop over loose geomaterials such as alluvium as well as over resistant bedrocks but incised meanders are always dug out in bedrocks.

Five terms are in use to indicate incised meanders which are developed due to vertical erosion downcutting or valley incision of bedrock viz. Inclosed and incised meanders represent those meanders of deep and narrow valleys which are inclosed by rocky walls. In fact, incised meanders mean the formation of meanders in older meanders through downcutting of valley floors.

Thus, it is apparent that entrenched meanders represent those incised meanders in which the valley floors have been deeply entrenched through vertical erosion consequent upon rejuvenation whereas ingrown meanders are those incised meanders in which one side of the valley has been deeply undercut resulting into the formation of hanging cliff.

Misfit meanders represent those meanders which are formed within the extensive former meanders due to substantial decrease in the volume of water.

The rivers develop extensive meander loops and belts in alluvial plains and are braided into several channels which wander in the extensive broad and flat valleys. When, by any reason, the volume of water in the concerned rivers decreases substantially, the channels become narrow. Such narrow meanders within the wider meanders are called misfit meanders because they cannot fit with the latter. The lakes formed due to impounding of water in the abandoned meander loops are called ox-bow or horse-shoe lakes.

When the curvature of the meander loops is so accentuated due to lateral erosion, the meander loops become almost circular and the two ends of meander loops come closer, consequently, the streams straighten their courses and meander loops are abandoned to form ox-bow lakes fig. The overland flow causes sheet erosion and depending upon the irregularities of the land surface, the overland flow may concentrate into narrow to wide paths. During the sheet erosion, minor or major quantities of materials from the surface of the land are removed in the direction of flow and gradual small and narrow rills will form.

These rills will gradually develop into long and wide gullies , the gullies will further deepen, widen and lengthen and unite to give rise to a network of valleys. Note: A valley can be formed in various ways like faulting, but here we are dealing only with the formation by means of exogenic geomorphic agent.

Once a valley is formed, it later develops into a stream or river. Courses of a river A river, which is the best example of the linear flow of running water through a valley, can be divided into three, on the basis of its course — upper course, middle course and lower course.

Adopt ClearIAS smart work approach! Online Classes with a difference! Get our newsletter Don't miss our email updates! We write simple, easy to understand articles, but always ensure high standards of quality. Comments Trully helpful for me to understand n Crete a coordination with tough geographical termology.

Damn good and easy to understand. Just love it. Thank you so much this is everything am looking for. If we bring out the Updated New Editions of the Static Files within your membership period , you will be able to download them without paying anything extra. Once the payment is made, you need to log in to the Downloads Page to download the files check your email for the login details. Subscribe to our newsletter and never miss an important update!

The landforms created as a result of degradational action erosion and transportation or aggradational work deposition of running water are called fluvial landforms. Fluvial Erosional Landforms Fluvial Erosional Landforms are landforms created by the erosional activity of rivers. Various aspects of fluvial erosive action include: Hydration: the force of running water wearing down rocks.

Corrosion: chemical action that leads to weathering. Attrition: river load particles striking, colliding against each other and breaking down in the process. Corrasion or abrasion: solid river load striking against rocks and wearing them down. Downcutting vertical erosion : the erosion of the base of a stream downcutting leads to valley deepening. Lateral erosion: the erosion of the walls of a stream leads to valley widening.