Overview

Erosion, deposition and the different materials they carry all contribute to how rivers shape surrounding land.

Erosion

Erosion involves the wearing away of rock and soil found along the river bed and banks.

Erosion also involves the breaking down of the rock particles being carried downstream by the river.

The four types of river erosion

  • Hydraulic action - the force of the river against the banks can cause air to be trapped in cracks and crevices. The pressure weakens the banks and gradually wears it away.
  • Abrasion/Corrasion – the force of the water in the river carrying stones and other materials grinds the bedload like a piece of sandpaper.
  • Attrition - rocks being carried by the river smash together and break into smaller, smoother and rounder particles.
  • Solution/Corrosion - soluble particles are dissolved by weak acids in the water.
Types of river erosion