Hard engineering-expensive, short-term, high impact on the landscape or environment and be unsustainable.
Building a sea wall- A wall built on the edge of the coastline. Advantages- Protects the base of cliffs, land and buildings against erosion. Can prevent coastal flooding in some areas.
Disadvantages- Expensive to build. Curved sea walls reflect the energy of the waves back to the sea. This means that the waves remain powerful. Over time the wall may begin to erode. The cost of maintenance is high.
Building groynes- A wooden barrier built at right angles to the beach. Advantages- Prevents the movement of beach material along the coast by longshore drift. Allows the build up of a beach. Beaches are a natural defence against erosion and an attraction for tourists.
Disadvantages- Can be seen as unattractive. Costly to build and maintain.
Rock armour or boulder barriers- Large boulders are piled up on the beach. Advantages- Absorb the energy of waves. Allows the build up of a beach.
Disadvantages Can be expensive to obtain and transport the boulders.
Soft engineering less expensive more long-term and sustainable, with less impact on environment.
Two main types of soft engineering.
- Beach management
- This replaces beach or cliff material that has been removed by erosion or longshore drift.
- The main advantage is that beaches are a natural defence against erosion and coastal flooding. Beaches also attract tourists.
- It is a relatively inexpensive option but requires constantmaintenance to replace the beach material as it is washed away.
- Managed retreat
- Areas of the coast are allowed to erode and flood naturally. Usually this will be areas considered to be of low value - eg places not being used for housing or farmland.
- The advantages are that it encourages the development of beaches(a natural defence) and salt marshes (important for the environment) and cost is low.
- Managed retreat is a cheap option, but people will need to becompensated for loss of buildings and farmland.