Fluvial Landforms

• Waterfalls

  • Hard rock is layered on top of soft rock
  • Soft rock erodes vertically as it is less resistant to erosion such as hydraulic action
  • A plunge pool forms
  • A notch forms under the hard rock
  • The hard rock collapses into the plunge pool which is further eroded by abrasion
  • The waterfall continues to retreat leaving a steep sided gorge
• Interlocking Spurs

  • Water does not have much energy
  • The water is not strong enough to erode resistant rocks
  • The river instead re-routes and curls around them
• Meander

  • As the water flows around a bend it is pushed towards the outer bank of the curve and this increases the levels of erosion
  • As the erosion continues the lower parts of the bank begin to undercut and create a river cliff
  • On the inside bank of the bend water has less energy therefore deposition occurs as the water can no longer carry the sediment
  • The build up of this sediment is called a slip-off slope
• Oxbow lake

  • The neck of the meander will gradually narrow
  • In the event of a flood, when the river has high discharge and energy, it will take the fastest course, which cuts of the meander
  • Deposition will occur in the channels, and an oxbow lake will be formed
• A flood plain is flat land either side of a river that naturally floods and is very fertile because of deposited sediment
• Levees

  • When a river floods, more sediment and most deposition occurs next to the river channel due to increased friction  
  • This leaves a ridge of higher material next to the river channel on both river banks known as a levee
• An estuary is a wide, sheltered body of water found at a river’s mouth, where it broadens into the sea which combines salt water from the sea and freshwater from a river
• Mudflats and salt marshes form at estuaries