Hard engineering processes Flashcards
What is hard engineering?
Using man-made structures as a barrier between the land and sea. These change or disrupt natural processes
Where are sea walls built?
In front of cliffs to prevent cliffs from eroding and then collapsing
Why are sea walls curved?
To deflect the energy of the waves back onto themselves
Advantages of sea wall
Very strong coastal defence with a long life-span. Can be used where wave energy is high
Disadvantages of sea wall
Very expensive. They prevent tourists from accessing the beach
What are groynes?
Barriers of wood or concrete at right angles to the beach
How do groynes provide coastal defence?
They trap sediment transported by longshore drift and help create wider beaches. These absorb more wave energy and reduce cliff erosion
Advantages of groyne
Cheaper than sea walls, don’t prevent access to beach and retain a wid, sandy beach for tourists
Life-span of groyne
Don’t last as long as other hard engineering strategies
How do groynes affect beaches further along the coast?
They deprive beaches further along the coast of sediment by trapping it
What is a revetment?
Wooden slated barriers built at the back of beaches to protect the base of a cliff
How do revetments work?
The energy of the waves is reduced when they break against the revetment
Life-span of revetment
Short
Cost of revetment
Cheaper than sea wall
How do revetments cause less damage to the beach?
Erode less beach material than a sea wall
