Erosional landforms

Question 1

V-Shaped valley

Answer 1

Formed by vertical erosion in a river’s upper course. They have their shape because the river erodes in a vertical direction more than a lateral one.

Question 2

Interlocking spurs

Answer 2

Upper course feature

Formed as the river flows around areas of harder rock which is more difficult to erode.

Question 3

Waterfalls

Answer 3

Upper course feature.
Hard rock sits above soft rock. The hard rock erodes slowly whilst the soft rock erodes more quickly leaving an overhang of hard rock and a plunge pool below as the soft rock erodes. Eventually the hard rock collapses into the pool and the waterfall ‘migrates’ up stream.

Question 4

Gorge

Answer 4

Upper course feature.

Linked to waterfall formation. The gorge is a steep sided channel left as the waterfall moves back upstream.

Question 5

Meanders

Answer 5

Middle course feature.
Lateral erosion moves water from side to side in the river channel and begins to form meanders. They grow as water on the outside of the bend moves quickly, causing erosion and a deep cross-section.
On the inside bend there is deposition and a sand/silt slip of slope is formed.

Question 6

Ox-bow lakes

Answer 6

Middle course feature.
As the meanders get eroded the space between them narrows. This space (known as a neck) is eventually eroded through, often in a flood event. This leads to a cut off horse shoe shaped lake. Known as an ox-bow lake.