A meander is a bend in a river. Meanders normally occur in the middle and lower courses where the water is moving more slowly. The river carves out S-shaped bends.

A meandering river

A meander belt is where there are several meanders occurring one after the other. The photo above shows a meander belt.

Erosion and deposition on a meander
Meanders are formed by erosion. As rivers move from source to mouth, they carry sediment and other material. Energy is needed to carry this sediment. But if the river has some spare energy, it can erode or wear away its bed, banks and other parts of the river.

Most erosion normally occurs on the outside bend of a meander. This is because the water has further to travel. Also, pieces of sediment may be thrown against the river banks to wear them away. Evidence of erosion on a river bank changes from river to river. Sometimes you can see tree roots hanging. Often there is a steep side to the outside river bank. The bank may overhang. There may be pieces of sediment in the river. Where a river bank overhangs, it is possible to put a hand or foot underneath the hanging part.

Erosion on the outside bend of a meander

On the inside bend of a meander, the water is flowing more slowly as it has less distance to travel. There is normally deposition on the inside bend. This is because the sediment is too heavy for the river to carry. Some inside bends of meanders can look like beaches. Sand and mud are deposited there.

A meander

Over time, there is more and more erosion on the meander. The shape of the meander changes from an S-shape to a loop. Oxbow lakes can often form from these loops.