V-Shaped Valleys

Question 1

With the help of Figure 11, describe how the shape of a river valley changes downstream

Answer 1

• The river valley changes from a v-shape near the source to a flat u in the middle course which becomes very wide near the mouth of the river
• The start of the river has steep sides

Question 2

Describe how a v-shaped valley is formed

Answer 2

• The river erodes vertically at a greater rate than it does horizontally deepening the valley
• The river continues to erode vertically, the river banks become less stable

Question 3

What is the second stage of a v-shaped valley forming?

Answer 3

• After a period of heavy rain, due to gravity, they collapse which forms the v-shaped valley
• The process is repeated, deepening the valley further

Question 4

Describe the final process of the formation of a v-shaped valley

Answer 4

• As the river flows through the valley it is forced to swing from side to side around more resistant rock outcrops (spurs).
• As there is little energy for lateral erosion, the river continues to cut down vertically flowing between spurs of higher land creating interlocking spurs.