Does erosion occur on the inside or outside of a meander?

Does erosion occur on the inside or outside of a meander?

Does erosion occur on the inside or outside of a meander?

Meanders and Associated Landforms

Does erosion occur on the inside or outside of a meander?

What is it?


A meander is a turning in a river or a change of its direction. Rivers erode the river bed from the outside of a meander where the river is faster and deposit sediment and silt on the inside of the meander where there is less energy. Eventually oxbow lakes can be formed in the erosion and deposition processes because two channels close up to form a separate lake. Meanders are mostly found further down the river where the plains are flat.

Origins, perhaps?


Meanders originate from fairly straight channels with developing pools and riffles. Usually there are obstructions found in a river that slow the fluvial flow down and the water has to flow over these which speeds speeds up the water flow. The higher velocity after the obstruction means there is more erosion happening, this area of greater erosion eventually turns into a pool and the slower area builds up from deposition of sediment carried in the river and turns into
Does erosion occur on the inside or outside of a meander?
a riffle.

What do meanders become?


Pools are areas in a river where the water is deeper and the discharge is greater because of the lack of friction, whilst riffles are shallow areas of water where the discharge slows down because there is higher friction against the bed. The bending occurs because of the way the water erodes; the water has a second flow of a helicoidal (corkscrew) motion which starts to erode the sides of the bank. Once the bending starts to happen the river erodes more on one side of the bank and deposits more on the other making a sharper bend, once this bend grows too sharp most commonly in floods the bend turns into an oxbow lake where the river runs over the land instead of going round the bend.

Human Uses


Meanders offer a strategic advantage. A town or city could be located within the meander for defensive purposes. Today, cities are located in and around meanders for trade purposes. Boats and barges can access the town to some extent for some trade. However, trade is only possible if the river is deep enough. Meanders can be used by tourists for boating trips.

Case Study: Shrewsbury

Does erosion occur on the inside or outside of a meander?
Shrewsbury (http://www.webbaviation.co.uk/shrewsbury/aerial-shrewsbury.htm)
Shrewsbury is a county town lying on the river Severn in the West Midlands region and is home to around 71 000 inhabitants. It is placed inside a meander, and was originally a medieval market town. The meander was very helpful for imports and exports as well as travel in the medieval ages. Since 1990, Shrewsbury has experienced severe flooding problems becuse of its location - in 2005 the defense systems were increased dramatically to hold back the potential flooding.

The land is very fertile due to all the layers of sediment and silt that have been forming over many years. Therefore, farming is a possibility on flood plains, around meanders. These crops must be resilient against high discharge in times of flooding.


Page initially found at: Meanders and Associated Landforms (no longer available)

The term ‘meander’ is one which refers to a winding curve or bend in a river. Meanders are typical landforms at the middle and lower courses of a river. Meander gradients are usually more gentle and they experience lateral (sideways) erosions which widen the channel of the river at the middle and lower courses of a river. Usually, the energy accompanying flow water in a river decreases progressively from the upper course of the river to the lowest course of the river.

Therefore, as water flows from the upper course of a river at very high energy, the impact it has on the landform on which the river is situated elicits erosional, transportation and deposition processes. Thus, during low flow conditions, straight river channels develop bars of sediment on their beds which leads to an eventual formation of deeper pathways which ultimately allow more flow of water and consequent formation of a sinusoidal flow of water.

As a result of the erosion on the outside portion the bend of flowing river water, erosion occurs, coupled with deposition on the inside portion of the sinusoidal curve. Thus the curvature of the pathway of river water flow increases, and the shape of the meander changes over time. The deposition process cuts off the original meander, leaving a horseshoe-like feature known as an oxbow lake. Meander geometry or median planform geometry is engaged in the technical description of meanders.

Some associated landforms include: Cut banks, Meander cutoffs, Incised meanders, Oxbow lakes, Scroll bars, and Slip-off slope.

Table of Contents

  • Formation of Meanders
    • Stage 1
    • Stage 2
    • Stage 3
    • Stage 4
  • 10 Interesting Facts About the Meanders

Formation of Meanders

Meanders are usually exhibited at the middle course of rivers. The major contributors to the creation of meanders include erosion, transportation, and deposition processes. The following are processes which lead to the formation of meanders in river bodies. These processes can be categorized into the following stages:

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Stage 1

During low flow conditions, straight river channels have bars of sediment on their beds. The flowing water weaves around these bars of sediment which in turn creates deeper pathways where most of the water flows called pools and shallow areas where less water flows called riffles. Ultimately, the river flow starts to swing from side to side.

Stage 2

In this stage, the river swings towards the bank lateral (sideways) erosion causes undercutting. At the opposite side of the channel where the velocity (speed of the flow of water) is lower material is deposited. Thus, the river does not get any wider. As a result of this stage, undercutting often occurs on the outer bank and deposition on the inner bank of the meander.

Stage 3

With persistent erosion along the outer bank, a river cliff or bluff is created as a result of hydraulic action and abrasion. Then, a point bar forms on the inner bank. The point bar or meander bar is a gently sloping deposit of sand, gravel, and pebbles. Just as the surface flow of water hits the outer bank it corkscrews, flows along the river bed then deposits eroded material on the inner bank.

Stage 4

This stage of meander formation eventually causes the neck of the meander to be breached by the river creating an ox-bow lake. A perfect example could be found in the River Derwent, North Yorkshire which is almost at the point of breaching.

Therefore, meanders are formed as a river goes around a bend in which most of the flowing water is pushed towards the outside portion of the water flow. The speed of water flow increases and the hydraulic action together with abrasion forces impacted results in increased erosion.

Usually, the meander formed is characterized by an inner bend which is slower in flow, making water flow to slow down considerably creating a gentle slope of sand and shingle as a result of deposition of the eroded material. More water is gained by the deepening bend as the river makes its way to the middle course of the river. A resultant increase in flow energy is also exhibited.

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Due to lateral erosion, the river widens and the river water flows over flatter land to develop larger bends which are referred to as ‘meanders.’ The characteristic sinusoidal (sinewave-like or snake-like) flow of water is therefore exhibited after the complete formation of meanders at the middle course of river bodies.

10 Interesting Facts About the Meanders

Fact 1: The word ‘meander’ comes from the Meander River located in present day Turkey and known to the Ancient Greeks as ‘maiandros.’ Principal Turkish rivers that drain into the Aegean Sea are the Gediz and Büyükmenderes (ancient Meander); the many loops and bends of the Büyükmenderes gave rise to the term meander in English.

Fact 2: Typical of meanders are Oxbow lakes. The oxbow lakes are also known as ‘cut-off lakes’. These lakes are usually formed by the normal process of fluvial meandering. Just after the cutoff meander is formed, the river flows into its end from the river and builds a small delta which eventually results in the formation of oxbow lakes.

Fact 3: The term ‘incised meander’ refers to meanders of a stream or river which has cut its bed down into the bedrock. Incised meanders can be found in Glen Canyon, United States of America.

Fact 4: Point bars are also known as ‘meander bars’ are often formed by the slow addition of individual layers of non-cohesive sediment in the inside bank of a meander by the accompanying migration of channels toward the outer bank.

Fact 5: Meanders are popularly described by the Stochastic theory. This theory states that: The meander train is assumed to be a result of the stochastic fluctuation of the direction of flow due to the random presence of direction-changing obstacles in the path of a river.

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Fact 6: The sharp bend in a river’s course, called a ‘meander’, is eventually cut off by a new channel that forms across the neck of land created by the meander. At the end of this process, the original meander is separated from the river, and its water stops flowing. At this point, an ‘oxbow lake’ is said to be formed.

Fact 7: Meanders are usually found in the middle course of rivers. They result from erosional and depositional processes at this level of rivers mainly due to the high energy and flow of water.

Fact 8: During the flow of river water which eventually leads to meander formation at the middle course, the fastest current is usually found on the outside of the bend, while the slowest current is found on the inside of the bend. This is due to the fact that the water on the outside bend of river water flow is deeper and runs faster than the water flowing at the inside portion of the bend.

Fact 9: Erosion, therefore, occurs on the outside of meander bends while deposition occurs on the inner side of meander bends (which might eventually lead to the formation of oxbow lakes).

Fact 10: Typically, meanders belong to a series of regular sinous curves, bends, turns, windings or loops in the channel of a stream, river or other watercourse and the zone within which a meandering stream moves its channel across either its valley floor or floodplain from time to time is known as the ‘meander belt.’

Where does erosion occur in a meander?

Erosion that forms a cut bank occurs at the outside bank of a meander because helicoidal flow of water keeps the bank washed clean of loose sand, silt, and sediment and subjects it to constant erosion. As a result, the meander erodes and migrates in the direction of the outside bend, forming the cut bank.

Which part of the meander has the most erosion?

Erosion is greatest beyond the middle of the bend in the meander. This causes the meander to migrate downstream over time.

What happens on the inside and outside of a meander?

The force of the water erodes and undercuts the river bank on the outside of the bend where water flow has most energy due to decreased friction. This will form a river cliff. On the inside of the bend, where the river flow is slower, material is deposited, as there is more friction. This will form a slip-off slope .

Does erosion occurs on the inside bend of a meander bend?

The fast water erodes the outside of the bend. The slower water deposits material on the inside of the bend. Continued erosion and deposition makes the bend bigger.