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

The wearing away of the sides and bottom of a river's channel is called corrasion. Corrasion, also known as abrasion, refers to the mechanical erosion of a river's bed and banks caused by the abrasive action of sediment and debris carried by the river's flow. As the sediment and debris move along the river bed, they scrape and scour the rock and soil, gradually wearing it away. This erosion process can be intensified by factors such as the speed and volume of the river's flow, the size and shape of the sediment particles, and the type of rock or soil that makes up the river bed and banks. Other processes that contribute to the erosion of a river's channel include hydraulic action (the force of water against the river banks), corrosion (the chemical breakdown of rock and soil by water), attrition (the collision and grinding of sediment particles against each other), and solution (the chemical dissolution of certain types of rock). However, corrasion is generally considered the primary process responsible for the wearing away of a river's channel.