Erosional and depositional landforms

• What are erosional and depositional landforms?

  • Found in MIDDLE COURSE
  • Meanders
  • Oxbow lakes
• What is a meander?


  A winding curve or bend in a river or stream.
• What are the characteristics of a meander?


  • Gentle, convex slope
  • Beach-like inside banks
  • Slow flowing water
  • Vegetation grows far from the water
• How is a meander formed?


  • As a river goes around a bend, the water is pushed to the outside and increases the speed of the water
  • This means there is more erosion (hydraulic action and abrasion) on the outside
  • This leads to undercutting of the river bank, forming a small cliff
  • Water on the inside slows down and deposits more material, creating a slip off slope of sand
• What is an oxbow lake?


  • Small horseshoe shape lake
  • Found metres away from a straight stretch of river
• What is Stage 1 of a oxbow lake formation?


  • Meander loop becomes very large
  • Only a small strip of land separates the river channel
  • Continuous lateral erosion further narrows the meander neck
• What is stage 2 of a oxbow lake forming?


  • River floods causing the main flow of water to cut straight across the meander neck
  • The new shortcut breaks down the banks and begins to form a new channel
• What is stage 3 of oxbow lake formation?


  • Flood recedes, and river returns to it's normal route
  • This process is repeated with every flood, until the new channel becomes so established that it becomes the main channel
• What is stage 4 of oxbow lake formation?


  • The loop of old river becomes more detached as it no longer receives river water
  • Marsh plants fill the new gap and it becomes an oxbow lake