Erosion

• Attrition: rocks carried by the river collide and break up into smaller, smoother pieces
• Abrasion: rocks carried by the river scrape along the bed and banks, loosening material, which is then carried away by the water
• Solution: soluble (something that dissolves) particles are dissolved by the river
• Hydraulic action: the force of the river against the banks - air becomes compressed within rocks and crevices, which weakens the banks