river landscapes

• | physical processes

  mechanical weathering

  1. water fills a crack in the rock
  2. water freezes & widens crack
  3. repeated freeze thaw increases size of crack until rock breaks
• | physical processes

  chemical weathering

  • rainwater is slightly acidic & reacts with minerals in rocks to dissolve them
• | physical processes

  biological weathering

  • roots grow into cracks and splits rock
• | physical processes

  sliding

  • rocks move down a slope due to the pull of gravity
• | physical processes

  slumping

  • river erodes at bottom of valley slope, making it steeper & material above slides down
• | physical processes

  erosion

  • HYDRAULIC ACTION: force of water on the bed and banks removes material
  • ATTRITION: load carried bumps together and wears down into smaller rocks
  • SOLUTION: mineral dissolve in water eg limestone
  • ABRASION: material caused by river rubs against bed & wears them way
• | physical processes

  transportation & deposition

  • the way in which river carries load
• | physical processes

  transportation & deposition

  • TRACTION: large boulders rolled along bed
  • SUSPENSION : particles carried in the flow, making river look brown
  • SALTATION: small pebbles bounce along bed