1.c. Coastal sediment is supplied from a variety of sources

Question 1

What three physical factors supply coastal sediment

Answer 1

• terrestrial
• offshore
• human

Question 2

How do terrestrial factors supply coastal sediment

Answer 2

• rivers are major sources of sediment input to the coastal sediment budget
• sediment input can be intermittent, usually occuring during floods. 80% of coastal sediment from rivers
• the origin of the sediment is the erosion of infland areas by water, wind and ice, as well as sub-aerial processes
• wave erosion contributes to coastal sediment budgets. Storms and rising sea levels can increase the erosion of cliffs
• material from cliff erosion-70% of ctoastal sediment
• longshore drift can move sediment from one coastal area to another

Question 3

How do offshore factors supply coastal sediment

Answer 3

• constructive waves bring sediment to the shore from offshore locations and deposit it
• wind blows sediment from other locations

Question 4

How do humans supply coastal sediment

Answer 4

• humans can prevent a prolonged deficit in the sediment budget by carrying out beach nourishment-to maintain equilibrium
• sediment brought on lorries, dumped on beach and redistributed by bulldozers
• pipelines can connect offshore sources with beaches and sediment can be pumped from one to another