Floodplains and levees

In the lower course, the river has a high volume and a large discharge. The river channel is now deep and wide and the landscape around it is flat.

However, as a river reaches the end of its journey, energy levels are low and deposition takes place.

Floodplains

The river will now have a wide floodplain.

A floodplain is the area around a river that is covered in times of flood. It is a very fertile area due to the rich alluvium deposited by floodwaters.

This makes floodplains a good place for agriculture.

Every time that a river floods its banks, it will deposit more silt or alluvium on the flood plain.

A build-up of alluvium on the banks of a river can create levees, which raise the river bank.

Illustration showing the details of a floodplain

Levees

Levees are formed by the repeated flooding of the river. When the river floods, the biggest, most coarse material will be dumped close to the river banks. This will continue to build up the levee over time.

Levee formation

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