Rivers - Waterfalls and Ox-Bow Lakes

Question 1

Name the 5 steps in the creation of a waterfall

Answer 1

1) River flows over alternative types of rocks.
2) River erodes soft rock faster creating a step.
3) Further hydraulic action and abrasion form a plunge pool beneath.
4) Hard rock above is undercut leaving cap rock which collapses providing more material for erosion.
5) Waterfall retreats leaving steep sided gorge.

Question 2

Name the 5 steps in the creation of ox-bow lakes

Answer 2

1. Erosion of outer bank forms river cliff. Deposition inner bank forms slip off slope.
2. Further hydraulic action and abrasion of outer banks, neck gets smaller.
3. Erosion breaks through neck, normally during a flood, so river takes the fastest route, redirecting flow
4. Deposition on the outer edges of the channel cuts off the meander leaving an oxbow lake.