Coastal Hard Engineering Flashcards

All 7 cards in this deck

What is a sea wall?

A concrete or stone barrier at the foot of cliffs or the top of a beach that deflects wave energy back out to sea.

Give one benefit and one cost of a sea wall.

Benefit: it protects cliffs from erosion and prevents flooding, and often carries a promenade. Cost: very expensive to build and maintain.

What is rock armour (rip rap), and give one cost of it.

Large boulders placed at the foot of a cliff or wall to disperse wave energy; it looks unattractive and makes beach access difficult.

What are gabions, and give one benefit of them.

Wire cages filled with rocks placed at the base of a cliff; they are cheap, quick to build and can improve cliff drainage.

What are groynes, and what is their main disadvantage?

Wooden or rock barriers built out to sea to trap sediment and widen the beach; they starve beaches downdrift of material, increasing erosion there.

What is the difference between hard and soft engineering at the coast?

Hard engineering builds artificial structures to stop or control the sea; soft engineering works with natural processes (e.g. beaches and dunes) to reduce erosion and flooding.

Give one cost of gabions.

Any one of: they look unattractive, or the wire cages rust and break over time so they don't last long.