As a river approaches its mouth, it usually flows over flatter land and develops increasingly large bends known as meanders
At this stage in its journey the river is eroding the landscape laterally
When the water reaches a meander most of the water is directed towards the outside of the bend
This increases the velocity and depth of the water at this point
The river therefore has more energy to transport material in suspension
This material will erode the outside of the bank through the process of abrasion
The bank will be undercut and a river cliff will form
Meanwhile, as there is less water on the inside of the bend, there is a decrease in velocity and depth
As the river loses energy, it begins to deposit some of its load
The deposited material builds up to form a gently sloping slip-off slop
Continual erosion on the outside of the bend results in the neck of the meander getting wider until, during a flood, the river cuts completely through the neck
This means a separate channel is formed
The majority of the water will now flow through the new channel as it is the most direct way of reaching the sea
However, some water will continue to take the old route
As less water is now travelling around the meander, it has less energy and so more deposition will occur
In particular, deposition will occur at entrances to the old bend
The deposited material will form a bar
Over time the material will block off the old meander so no more water can enter it
The deposited material will be slowly colonised as plants will begin to grow and new land will eventually form
The original meander will remain in the landscape as a crescent shaped area of water known as an ox-bow lake
This lake will eventually dry up except during periods of heavy rain

	Criado por rosetinley mais de 10 anos atrás

GCSE Geography (Rivers) Notas sobre Landforms Created by Rivers, criado por rosetinley em 10-11-2013.