Factors affecting the development of erosional landforms

Question 1

v shaped valleys

Answer 1

• formed by vertical erosion of a river
• weathering and mass movement occur on valley sides while river erodes base of slopes; leads to backwasting (steepening of valleys)
• angle of v shape depends on; rate of downward erosion by river, climate, location, rock type

Question 2

waterfalls and gorges

Answer 2

• occur on margins of horizontally bedded rock
• e.g HIGH FORCE whin sill…hard igneous rock is on top of carboniferous limestone which is a softer rock as in layers
• whin sill isn’t supported and collapses moving waterfall backwards
• gorge is formed by retreating waterfall and is a narrow, steep sided valley

Question 3

Potholes

Answer 3

• hole in base of stream or river

- formed through abrasion by pebbles held up by turbulent flow in the eddies of the stream

Question 4

load carried

Answer 4

heavier/sharper the load, the greater the potential for erosion

Question 5

velocity of river

Answer 5

greater the velocity, more erosion

Question 6

geology

Answer 6

weak unconsolidated rock e.g sand/gravel are more easily eroded than consolidated rock

Question 7

ph

Answer 7

water more acidic=more erosion