2.5. Erosion, Transportation and Deposition

Question 1

What is longshore drift?

Answer 1

The movement of sediment along the coastline.

Question 2

Why is longshore drift important?

Answer 2

It’s what is moving sediment around the sediment cell and cause cause an increase or decrease in erosion.

Question 3

What happens if longshore drift is interrupted by management?

Answer 3

It can lead to distortions of natural patterns, depriving beaches of material and depriving beaches of material and exacerbating erosion.

e.g. unprotected beaches in Appleton have been starved of so much sediment that annual erosion rates have accelerated to reach up to 10m per year -> sediment builds up through constructive waves but groins stop the buildup on the other side of the groyne.

Question 4

When does deposition take place?

Answer 4

When the velocity of water or wind falls below a critical value for a particular size of particle and can no longer be transported.

Question 5

Why is deposition important?

Answer 5

It creates sediment stores and without it, no beaches, spits or bars could be created