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.

Hard engineering involves the use of heavy machinery to build artificial structures which work against nature to reduce flood risk.

Find out more about hard engineering.

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.

Hydraulic action is when the force of fast-flowing water hits the bed and banks and forces water and air into cracks in the bedrock. The repeated changes in air pressure cause the river bed to weaken.

Find out more about river erosion.

The increase in lateral (sideways) erosion.

Find out more about the long profile of a river.