Upper-Course Landforms: River Erosion

• Feature: V-Shaped Valley


  • A V-shaped valley is a steep-sided river valley.
  • It has a narrow floor and steep sides.
  • It forms in the upper course of a river.
  • It is a feature of erosion.
• Explanation & Example: V-Shaped Valley

  • Vertical erosion makes the river cut down into its bed.
  • The processes of abrasion and hydraulic action deepen the river channel.
  • Soil and rock are weathered from the sides of the valley.
  • Mass movement moves weathered material to the river.
  • Over time, the valley becomes a deeper V-shaped valley.

  Examples: Upper course of the River Liffey in Co. Wicklow, and the River Moy in Sligo.
• Feature: Interlocking Spurs


  • Interlocking spurs are areas of high ground that jut out on either side of the river.
  • They 'interlock' like parts of a zip.
  • Interlocking spurs are formed in the upper course.
  • They are a feature of erosion.
• Explanation & Example: Interlocking Spurs

  • Interlocking spurs are formed when a river meets sections of hard (resistant) rock.
  • The river cannot erode the sections of hard rock, so it flows around them.
  • The river erodes downwards (vertical erosion) using the processes of hydraulic action and abrasion.
  • This leaves interlocking pieces of high ground sticking out - spurs - on either side of the river.

  Examples: Upper courses of the River Liffey, Co. Wicklow, and the River Barrow in Co. Laois.