Coastal Defences Flashcards
Name all the hard engineering techniques
Sea wall, rip rap (rock armour), groynes and gabions
Name all the soft engineering techniques
Beach nourishment, dune nourishment, reprofiling and managed retreat
Pros of a sea wall
Protects base of cliff, land and buildings against erosion and can prevent coastal flooding in some areas
Cons of sea wall
Expensive to build and maintain. Curbed sea wall cans reflect the energy of the wave back to the sea causing the waves to remain powerful. Also and eye sore
What is a sea wall
A solid wall that is used to separate land from the sea
What are groynes
A wooden barrier built at right angles to the beach
Pros of groynes
Prevents longshore drift moving beach material along the coast. Allows the build-up of a beach, which are an attraction for tourists and a natural defence from erosion
Cons of groynes
Can be unattractive and costly to build and maintain
What are gabions
Large boulders piled up on the beach in steel cages
Pros of gabions
Absorbs wave energy and allows the build-up of a beach
Cons of gabions
Can be expensive to obtain and transport the rocks and can also be unattractive
What is beach nourishment
Replacing beach or cliff material that had been removed by erosion or longshore drift
Pros of beach nourishment
Natural defence against erosion and coastal flooding and beaches attract tourists, also relatively inexpensive
Cons of beach nourishment
Requires constant maintenance as gets washed away easily
What is managed retreat
Areas of the coast are left to erode and flood naturally (usually on places that are considered low value)
