Hard and soft engineering Flashcards
What are the negative impacts of coastal recession?
Economic and social losses
What is hard engineering?
Making a physical change to the coastline
using hard wearing materials
rocks, concrete, metal etc…
Give some examples of hard engineering
Sea walls
Revetments
Groynes
Rip-rap
Offshore breakwaters
Explain sea walls (positives and negatives)
Hard concrete
curved to dissipate wave’s energy
What are revetments?
Angled walls to help break the force of the waves and limit erosion.
What are groynes?
Stone or wooden fences 90 degrees to the coast. Stop transportation of material through longshore drift.
What are the positives and negatives of sea walls? Give 1 example for each
good long term solution - very resistant
Bad - expensive to build and maintain
What are the positives and negatives of revetments?
More cost effective than a sea wall, reduce rate of erosion.
need constant maintenance.
What are the positives and negatives of Groynes?
create wider beaches which slows down waves. relatively cheap.
Beaches down coast = narrower. Erosion and flooding there is more likely.
What is Rip-rap?
Boulders placed on a beach to dissipate wave energy and reduce erosion.
Often placed in front of sea walls.
What are the positives and negatives of Rip-rap?
Long lasting, cheap
Hazard for people accessing the beach
Gaps between rocks allow weathering and erosion to continue.
What are offshore breakwaters?
Rocks lined up parallel to the shore.
Aim - to dissipate wave energy and reduce erosion.
What are the positives and negatives of off shore breakwaters?
Calmer conditions behind breakwater - safe for recreation.
Can cause wave patterns to change. Expensive to install.
What is soft engineering?
Use of natural systems for coastal defence.
Give some examples of soft engineering
Cliff re-grading
Beach nourishment and reprofiling
dune regeneration
