Sea wall - made of concrete,£3000 per linear m, can be curved, reflects and absorbs wave energy, effective for years, unattractive, disturbs natural processes e.g - long shore drift
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Groynes - usually made of wood, £5000 each, prevents LSD, keeps beach in place, effective for years. Unattractive, difficult to walk along beach
Rip rap - large rocks placed in front of cliff, £300 per m. Dissipates wave evergy, can be v.cheap, effective for long time. Can make beach inaccessible to tourists, unattractive, ineffective in storm conditions
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Soft engineering:
Beach replenishment - placing of sand and pebbles on beach, £5000 per 100m, looks natural, cheap, best natural defence as dissipates wave energy, many affect plant + animal life in area, requires constant maintenance, can be washed away in a year
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Cliff regrading - cliff cut back given gentle slope, stops slumping, v.natural, things can grow on it, not effective alone, any homes on cliff may have to be demolished.
Managed retreat - Allowing sea to gradually flood land or errode cliffs, creates new habitats for plants + birds, cheap (-costs of damage) upsetting for landowners who lose land,hard to estimate extent of sea movement especially with rising sea level
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Walton on the naze- coastal town in Essex. Rock types London clay + red crag, easily eroded by sea. Cliffs suffer from slumping, LSD moves sand from south to north. Northern area not protected only tower + some builings. South end has town of 12000 p
1977 project completed consisted of sea wall, breakwaters + groynes +cliff regraded. Sunny point road each property £400,000. Nettles planted on cliff preventing people walking off the path, bottom of cliff sea wall.
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1998 council payed £167,000 for 300 tonnes of Leicester Granite to be placed around the tower. This rip rap slowed down erosion but didnt stop it.
1999 northern part of coastline was replenished with sand + pebbles that had been dredged from Harwich harbour but by 2003 had already been removed due to powerful LSD.
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Other cards in this set
Card 2
Front
Rip rap - large rocks placed in front of cliff, £300 per m. Dissipates wave evergy, can be v.cheap, effective for long time. Can make beach inaccessible to tourists, unattractive, ineffective in storm conditions
Back
Groynes - usually made of wood, £5000 each, prevents LSD, keeps beach in place, effective for years. Unattractive, difficult to walk along beach
Card 3
Front
Beach replenishment - placing of sand and pebbles on beach, £5000 per 100m, looks natural, cheap, best natural defence as dissipates wave energy, many affect plant + animal life in area, requires constant maintenance, can be washed away in a year
Back
Card 4
Front
Managed retreat - Allowing sea to gradually flood land or errode cliffs, creates new habitats for plants + birds, cheap (-costs of damage) upsetting for landowners who lose land,hard to estimate extent of sea movement especially with rising sea level
Back
Card 5
Front
1977 project completed consisted of sea wall, breakwaters + groynes +cliff regraded. Sunny point road each property £400,000. Nettles planted on cliff preventing people walking off the path, bottom of cliff sea wall.
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