Hard Engineering Flashcards
What are revetments?
A form of wooden or rock beach fences that allow for waves to pass through but reduces their power by absorbing their energy
What are the advantages of revetments?
- Can be implemented quickly and swiftly
- Relatively cheap in the short term
What are the disadvantages of revetments?
- Unattractive
- Might reduce beach access
- Requires regular maintenance and repair
What are gabions?
Open wire cages filled with rocks placed at the foot of the cliffs or at the back of coastlines to absorb wave energy. They prevent cliff getting undercut and collapsing due to gravity!
What are the advantages of gabions?
- Can be implemented quickly and swiftly
- Relatively cheap
What are the disadvantages of gabions?
- They look unnatural
- Deteriorates over time and require maintenance
- Not particularly effective
- Can have rodents between gaps in the rocks
What are groynes?
They are wooden or boulder structures extending at right angles from a beach. Material accumulated from longshore drift to build up beach width and height
What are the advantages of groynes?
- Traditional technique
- Quite effective
- Increased beach area which benefits tourism
What are the disadvantages of groynes?
- Built from unsustainable hardwood sources
- Beaches robbed of sediment so rates of erosion can increase along some parts of the coastline
What is rock armour?
They are large boulders of highly resistant rock places at the foot of cliffs. They are similar to gabions but aren’t kept in metal cages
What are the advantages of rock armour?
- Effective at absorbing wave energy
- Long lasting as require little maintenance
- More natural looking than gabions
What are the disadvantages of rock armour?
- Can restrict and reduce beach access
- High transport costs
- Hazardous the people climbing on them
What is a sea wall?
They are thick concrete or rock encasements at the shore front. Can be straight or recurved to assist deflecting waves back to sea.
What are the advantages of sea walls?
- Standard frontage of seaside so don’t look unusual and won’t put off tourists
- Very effective
- Long lasting so require little maintenance
What are the disadvantages of sea walls?
- High construction costs
- The maintenance that is required is important as the sea wall could be undercut and fractured beneath it’s foundation
