Coastal management techniques

Coastal management is about two things. The first is resolving conflict between different users of the coast and between those users and the well-being of coastal ecosystems. The second is taking action to meet big changes that threatened long stretches of coast. Two changes prevent risk, risk of coastal erosion and coastal flooding.

 

Coastal erosion- quite normal and natural but in some places at fast speeds. The 20-30 metre high cliffs made of soft sands, gravels, clay are retreating 1 metre per year.

 

Coastal flooding-  storm surges are the greatest flood threat. These are caused by low air pressure, which raises the height of the high-tide sea. Strong onshore winds then drive the ‘raised’ sea towards the coast and are capable of breaching coastal defences and flooding areas.

 

Hard-engineering management

Hard engineering involves building some sort of sea defence, usually from rocks or concrete. It aims to protect the coast from erosion and the risk of flooding by working against the power of waves.

Some examples: the groyne, wooden revetment, recurved steel wall, gabion and the rip-rap

Soft-engineering management 

These methods of coastal management try to work with natural processes.

Beach replenishment- pumping or dumping sand and shingle back onto the beach to replace eroded material.

Building bars- underwater bars located just offshore to reduce wave energy.

Fencing, hedging and replanting vegetation- this helps to preserve a beach or sand dune by reducing the amount of sand that is blown inland.

Cliff regarding- the angle of a cliff is reduced so that it is not so steep because this reduces the likelihood of cliff retreat by mass movement.