2.8

Question 1

Physical processes causing an erosion threat

Answer 1

• resistance of geology
• distance of fetch
• softer geology being vulnerable to mass movement due to the increase in pore water pressure
• structural weaknesses eg rock dips and faults
• strong longshore drift removes eroded debris quickly exposing the cliff

Question 2

Human processes causing an erosion threat (interference in the sediment cell)

Answer 2

• mitigation processes
  
  • groynes: trap sediment starving areas that would have received the sediment through deposition from longshore drift leaving them unprotected
  • sea walls: prevent natural erosion of cliffs which would provide sediment that could be deposited providing protection, waves also hit the defences and reflect energy onto other nearby areas
• dams: trap sediment that would have naturally flowed downstream to replenish areas and help to protect them
• dredging: removes sediment that would be naturally moved by longshore drift to protect the coast reducing sediment supply