Many different types of man-made barriers are used to protect our coast.
Sea walls are barriers along the shoreline that bear the impact of waves and protect the land behind. The materials used and height of the walls vary, according to the strength of defence required. Reinforced concrete walls are often used to protect towns and cities.
Other types of sea wall include:
- revetments - sloping structures built to absorb wave impact and protect the cliff or settlements behind
- gabions - rocks and boulders, wired into mesh cages, and placed in front of areas that are vulnerable to erosion
- rock armour - large rocks or boulders placed at the foot of dunes or cliffs to absorb wave energy, and help hold beach material in place.
These are huge rocks or concrete blocks, sunk offshore to alter the wave direction and diffuse water energy.
These are barriers, usually made from timber, concrete or rock, which run from the shoreline out to sea, and help to reduce the loss of sand and shingle from the beach due to drift along the shore (longshore drift)
Floodgates and barriers
These form an opening for water to pass through a wall, and are usually open but can be closed to protect land from a storm surge - for example the Thames Barrier.