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Formation of river landforms - Coggle Diagram
Formation of river landforms
V-Shaped valleys
A steep sided, narrow river valley
It takes the form of a V - shape in its cross profile
https://www.bbc.co.uk/bitesize/guides/z6jx382/revision/1
- This is a diagram of a V shaped valley and also a video of how they are made
Waterfalls
Where fast flowing water plummets over a vertical cliff
They usually form when a river flows over a hard band of rock, because the water cannot corrode the hard rock a step is formed - and this is the start of a waterfall
There is allways a plunge pool underneath of the waterfall due to abrasion and hydralic action, these can be several meters deep in the middle
https://www.bbc.co.uk/bitesize/guides/z6jx382/revision/2
- This is a diagram of a waterfall and also a video of how they are made
Gorges
Commonly formed by the upstream retreat of a waterfall
Erosion undercuts the hard rock forming the waterfall to create an overhang
The overhang will finally collapse into the plunge pool cauing the waterfall to retreat upstream
A gorge takes thousand of years to create, because year by year the waterfall will retreat little by little back upstream, creating a gorge
Meanders
Extenstive and Elaborate bends in the river
The fast flowing water goes around the outside of the bend and erodes it more, on the inside of the meandder, sediment is placed creating a flood plain.
Riffles are the shallow areas often associated with the straighter sectorns of the rivers, in between meanders, they usually have rocky beds and a turbulant flow due to the friction along the river bed
Pools are the deeper areas associated with the meander bends, they usuallly have finer sediment and less turbulence because there is less friction on the river bed
https://www.bbc.co.uk/bitesize/guides/z6jx382/revision/3
- facts about meanders and a video expalining it
Ox-box lakes
These are usually in the middle of the river
They repesent the old meander bends that have been cut off by faster flowing during floods.
https://www.bbc.co.uk/bitesize/guides/z6jx382/revision/4
- diagrams of the ox-bow lakes and a video explalining it
Levees
Raised river bank
Found on the lower course of the river
Step by step on how levees are created
Water overtops the river banks in a flood
Sediment is collected at the side of the river banks
The heavier sediment is deposited first and then that traps all of the smaller sediment in it
The flood goes down and there is a bit more of a bank on the river
the levees are increased by as much as a few meters after a few of floods
In the USA, the when they talk about levees they are talking about man made ones
Flood plains
Found in the middle and the lower river
They are large areas, that are usually covered in grass
They are the places which are most likely to be covered in water when the river floods as they are flat and the water can easily run onto them when it has burst out of the river banks.