The Nant Tanilwyth stream joins the River Severn just before a bend in the river.

The Severn emerges from the right and Nant Tanllwyth from straight ahead.

The River Severn turns a corner here dropping some of its load on the inside of the bend.

The water on the inside of a corner moves slower and has less energy to carry its load - when the flow of the water is too slow - the load is deposited or dropped.

This is the process of deposition. The deposited material is called sediment.

Erosion wears away the banks on the outside of a meander bend, to make a stream/river cliff. This is because the water current is strongest (fastest speed) on the outside of a bend.

Most of the erosion here happens after heavy rain

After a lot of rain, the power and force of the water crashes into the bank attacking, and wearing away the bank. This process is known as Hydraulic Action.

Key Vocabulary

Confluence
The point at which a tributary joins the main river.

Tributary
A small river / stream which joins the main river

Transportation
The movement of material eroded by a river (called the load) from one place to another.

Erosion
Erosion is the wearing away of the bottom  and sides of the rivers by the force of the water, and material carried by the water.

Hydraulic Action
This process involves the force of water against the bed and banks