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14 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Hard engineering |
Man-made (mainly concrete) structures to protect the coast from eroding |
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Soft engineering |
Natural structures to protect the coast from eroding |
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Management strategies |
-do nothing -retreat the line -hold the line -advance the line |
There are 4 |
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Do nothing |
-Nothing is done, the coastal area erodes at it's usual pace -Soft engineering |
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Retreat the line |
-Let the coast erode but move people and businesses away from at-risk areas -This may cause conpensation for people -Mainly used where the land is valuable or important facilities need protecting -Soft engineering |
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Hold the line |
-Use sea defences to keep the coast where it is -Expensive -Usually hard engineering |
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Advance the line |
-Use sea defences to build up the coast line and move the coast backwards -Very expensive -Used when new areas are needed for economic or ecological development |
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Barrier Beach (Bar) |
A sand or shingle beach built parallel to the coastline to "advance the line" and take energy from the waves sk they are calmer when they get to the real beach |
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Groynes |
-Wooden, concrete or rock barriers that are at right angles to the beach -Trap material by stopping LSD, making the beach wider so more energy is absorbed before the waves reach the cliffs or seafront -Should be 100m apart for effective protection -Require very little maintenance once built -Can cost up to £200,000 per groyne -Some think they are ugly and ruin the landscape -Create problems further down the coast as they trap all the sediment in one location, leaving other parts of the coast exposed |
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Why Groynes Work |
The more beach there is, the more friction there is, the more energy is needed to get over the beach, the less energy the waves will have at the end |
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Rip rap/rock armour |
-Large boulders that are piled up at the top of the beach -Absorbs the waves' energy -Require very little maintenance once in place -Cheaper than a sea wall -Ineffective against large storms -Has a more limited life span than a sea wal |
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Sea Wall |
-A concrete barrier that reflects the waves back into the sea -Often curved -Protects settlements from flooding and erosion -Very effective at stopping erosion at the area they are built in -Require very little maintenance -Seen as very ugly -£5000 per metre (very expensive) |
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Managed Retreat |
-The controlled flooding of low lying areas of the coast -Areas are often of low value (e.g. farming areas) -Sometimes sea -Cheap option compared to paying for sea defences-Creates a salt marsh which can provide habitats for wildlife and a natural defence against erosion and flooding-Land is lost as it is reclaimed by the sea.-Landowners need to be compensated (£5,000 - £10,000 per hectare.) |
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Gabion |
Metal cage filled with rocks |
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