Name one landform of river erosion and, with the aid of a diagram, explain how it was formed. Sample Question
Sample Answer
Description – A waterfall is a landform of river erosion. It occurs when a river flows over a vertical drop. Examples – Examples of waterfalls in Ireland are Torc Waterfall near Killarney, Co. Kerry and Powerscourt Waterfall in Co. Wicklow. Processes – When a river flows over an area comprising a layer of hard rock above a layer of soft rock, the soft rock gets eroded quicker by the processes of hydraulic action, abrasion and solution. Explanation – This creates a fall in the river. A plunge pool forms at the base of the waterfall due to the force of the falling water. Undercutting then takes place and creates an overhang. This overhang eventually collapses and the waterfall retreats.
Plunge pool undercuts hard rock which collapses Rapids
Hard rock Soft rock
Softer rock erodes more quickly
Hard rock Soft rock
Plunge pool Waterfall
Hard rock Soft rock
New plunge pool
1. At X in the diagram, the river is rolling and dragging stones along the river bed (traction).
This is an example of: River erosion
River transport River deposition [tick (3) the correct box]
2. The diagram shows four river features that are labelled A–D.
A B C D
Feature Delta
Oxbow lake Distributary Levee
In the boxes provided, match each letter on the diagram with the correct feature listed in the table.
