Rivers

• What topic is the revision Blast focusing on?

  River Landscapes
• What is a tributary?

  A small stream feeding into a river
• What is another name for a drainage basin?

  Catchment area
• What does a drainage basin represent?

  Area drained by one river and its tributaries
• What is a confluence?

  Where two or more rivers join
• What is the source of a river?

  Where the river starts its journey
• What is the mouth of a river?

  Where it reaches the sea
• What is a watershed?

  Area of highland separating drainage basins
• What are the processes of erosion in river landscapes?

  • Erosion: Wearing away of river banks
  • Hydraulic action: Water force hitting banks
  • Abrasion: Sediment scratching river banks
  • Attrition: Rocks breaking into smaller pieces
  • Solution: Chemical reaction dissolving rocks
• What is hydraulic action in river erosion?

  Water force hitting banks and weakening them
• What is abrasion in river erosion?

  Sediment scratching and scraping river banks
• What is attrition in river erosion?

  Rocks hitting each other and breaking
• What is solution in river erosion?

  Chemical reaction dissolving rocks in water
• What is the order of transportation processes from largest to smallest material?

  Traction, saltation, suspension, solution
• What is traction in river transportation?

  Heavy rocks rolled along the riverbed
• What is saltation in river transportation?

  Small stones bouncing on the riverbed
• What is suspension in river transportation?

  Very small particles suspended in water
• What is solution in river transportation?

  Material dissolved in water
• What are the features of the upper course of a river?

  • Mainly vertical erosion
  • Steep gradient
  • High energy
  • Large boulders deposited and rolled
• What are the features of the middle course of a river?

  • Lots of deposition on inside bends
  • Erosion occurs laterally
  • Deeper channels
  • Greater discharge and volume of water
• What are the features of the lower course of a river?

  • Lateral erosion continues
  • Fine sediment builds floodplain
  • Large load with tiny particles
  • Greatest discharge and velocity
• What is discharge in river terminology?

  Volume of water passing through a river
• Is discharge the volume of water passing through a river?

  False
• Does discharge increase downstream?

  True
• Does lateral erosion broaden the river valley?

  True
• What are the stages in the formation of a waterfall?

  1. River flows over hard rock
  2. Soft rock eroded faster
  3. Undercutting creates overhang
  4. Overhang collapses
  5. Plunge pool develops
  6. Waterfall retreats upstream
• What term describes rocks carried along by river water?

  Load
• How do plants help reduce river erosion?

  Roots bind soil together for reinforcement
• What is a slip-off slope?

  Deposited material on inside of a meander
• What are gabions?

  Metal cages filled with rocks
• What category of river engineering uses gabions?

  Hard engineering
• What are disadvantages of using gabions?

  Expensive to install and maintain
• What is the term for deposited material on the inside of a meander?

  Slip off slope
• What is another name for a slip off slope?

  Point bar
• What method is used to reinforce river banks with metal cages filled with rocks?

  Gabion cages
• In which category of river engineering are gabions used?

  Hard engineering
• What is the main focus of hard engineering in river management?

  Building structures
• What are the disadvantages of using gabion cages?

  • Expensive to install and maintain
  • Can be dangerous
  • Unsightly when broken
• What does the picture show in the context of river geography?

  A river cliff or bluff
• What are the stages in the formation of an oxbow lake?

  1. Meander neck erodes over years
  2. Flood occurs, breaking through neck
  3. Water follows new shorter channel
  4. Deposition reduces flow around old meander
  5. Old meander is cut off, forming oxbow lake