Coastal Management - More Hard Engineering
Geography: Cambridge International GCSE (2027 Exams), topic 2.3.4
Coastal Defences - Hard Engineering 2
Hard engineering strategies aim to reduce the effects of flooding and erosion by building man-made structures that control the sea's flow. Examples of hard engineering strategies include:
Revetments
- A cheaper version of a seawall. They are placed against the base of a cliff.
- They are made from wood or concrete and they look like a sloping ramp.
- They deflect (change the direction of) wave energy to protect the cliff’s base as this reduces undercutting.
- Advantages:
- They are cheaper to install than a sea wall and do a similar job.
- They need less maintenance than a sea wall.
- Disadvantages:
- They are quite expensive to install.
- They look quite unnatural and unattractive.
Offshore breakwater 1
- These shelter the beach from waves.
- Breakwaters can be constructed with one end linked to the shore or positioned offshore from as little as 100 m up to 300–600 m from the original shoreline.
- They are constructed with rubble/rocks and/or concrete
Offshore breakwater 2
- Advantages:
- Very effective as they take almost all the energy from the waves so they work well.
- Disadvantages:
- Difficult to maintain, expensive to maintain.
- Ruin the beach effect of waves lapping on the shore.
- Unnatural.
- Can be destroyed by storm waves.
- Look unattractive.
Tidal barrage
- A feature of river estuaries.
- These are big walls across an estuary that can be opened or closed.
- Advantage - really effective at protecting whatever is behind them (e.g. London - Thames Barrier).
- Disadvantage - very high costs.
Test yourself on Coastal Management - More Hard Engineering
What kind of hard engineering scheme are big walls across an estuary that can be opened or closed?