The wearing away of the sides and bottom of a river channel is called

The wearing away of the sides and bottom of a river channel is called corrasion. This process is also known as abrasion and involves the scraping and rubbing of rock material against the river bed and banks, which results in the erosion of the channel. The particles that cause corrasion include pebbles, sand, and boulders that are transported by the river. Corrasion is one of the major processes responsible for the formation of river valleys and the alteration of river channels over time.