Coastal defences are used to prevent or minimise coastal erosion. Coastal defences are either hard or soft engineering defences.
Soft engineering is a more sustainable, long-term and potentially cheaper approach to coastal defence, working with natural processes to protect the shoreline.
Hard engineering can be costly, have a shorter life time and be more intrusive than soft engineering, providing a temporary fix. Hard engineering defences often cause more problems elsewhere.
Sea walls are concrete walls built on the edge of the coastlines to protect towns, and they absorb wave energy and protect cliffs behind. They may also have a curved top to reflect waves back out into the sea.
Groynes are wooden barriars that are built at right angles to the beach. They trap sand between them to prevent longshore drift.
Sand is added to the beach to replace the sand that has been washed away by longshore drift, allowing the beach to absorb the wave energy.
Managed retreat allows the land to erode or flood naturally, and is allowed in places that are considered of being low value - however, it is only a temporary solution to highly erosive areas.
Sloping ramps made from wood or concrete which absorb the wave energy while allowing sand and other sediment to filter through them, so longshore drift is not prevented.
Rock Armour/Boulder Barriers
These are large barriars placed on the beach which absorb the wave energy and allow the beach to build up. They can be moved, but transporting can be costly (economically and environmentally).