Floodplains form due to erosion and deposition. Erosion removes any interlocking spurs, creating a wide, flat area on either side of the river. During a flood, the material being carried by the river is deposited (as the river loses its speed and energy to transport material). Over time, the height of the floodplain increases as the material is deposited on either side of the river. The floodplain is often a wide, flat area caused by meanders shifting along the valley.

Find out more about landforms in the lower course of the river.

It’s made up of alluvium (deposited silt from a river flood).

Find out more about landforms in the lower course of the river.

The main characteristics of levees are:

• raised river banks
• consist of gravel, stones and small sediment
• steep on the channel side, gentle sloping on the land side
• relatively flat top covered in grass

Find out more about landforms in the lower course of the river.

Characteristics of a flood plain include:

• A large area of flat land either side of a river
• layers of alluvium cover the flood plain
• a river bluff along the edge of a flood plain
• meander scars
• levees
• rich, fertile soil
• reeds and marsh plants

Find out more about landforms in the lower course of the river.

When a river floods friction with the floodplain leads to a rapid decrease in the velocity of the river and therefore its capacity to transport material.  Larger material is deposited closest to the river bank. This often leads to large, raised mounds being formed. Smaller material is deposited further away and leads to the formation of gently sloping sides of the levees.

Find out more about landforms in the lower course of the river.