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Published byEmily Spencer Modified over 8 years ago
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Why bother? Two British conservation groups say the UK's system of coastal defence benefits only a few people, at the expense of irreplaceable wildlife habitats. The report says that unless the concrete coastal defences built in many areas to keep the sea at bay are realigned, 200 square kilometres of habitat will disappear underwater. It says these sea walls, which stretch for more than 2,300 km, "are not allowing the habitat to retreat as sea levels rise".
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So what are the options?
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Option 3 In 1998 the UK government abandoned building higher and bigger sea walls decided it needed to be more sustainable: Managed retreat, or “managed realignment” involves dismantling any existing coastal defences, and allowing the sea to encroach inland to a pre-determined ‘set back’ line. This reduces wave energy, and minimises the effects of any predicted rise in sea level as a result of global warming. It is a form of land use zoning.
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Belle Tout Lighthouse Managed retreat or managed realignment involves dismantling any existing coastal defences and allowing the sea to encroach inland. Reduces wave energy and minimises the effects of any sea level rise.
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Managed Realignment Managed retreat, or “managed realignment” involves dismantling any existing coastal defences, and allowing the sea to encroach inland to a pre- determined ‘set back’ line. This reduces wave energy, and minimises the effects of any predicted rise in sea level as a result of global warming. It is a form of land use zoning. What is meant by land use zoning in the diagram below?
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Sacrifice lower value land…
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Your views… What are the advantages/disadvantages of managed retreat along the Holderness Coastline?
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Option 2 Beach nourishment Dune regeneration Marsh creation Soft engineering: a sustainable approach to managing the coast without using artificial structures.
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Beach nourishment Sand/shingle brought by lorry or barge Very expensive Needs repeating Does not prevent beach erosion but helps protect cliffs under threat of collapse.
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Sand Dunes and coastal management Sand dunes are created by strong winds- not coastal erosion or deposition!
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Salt Marsh Creation “A pioneering project to restore Britain's salt marshes, which are under threat due to the effects of global warming, represents a victory for environmental groups. Sea defences erected to protect farmland on a mile-long stretch of coastline in the Wash, East Anglia, have been dismantled to return 200 acres to salt marsh. The project is expected to see the return of thousands of wading birds and the re-emergence of salt-water plants in the Freiston Shore nature reserve in Lincolnshire within six years. To combat rising sea levels and natural sinkage in south- east England, flood defences to protect homes and farmland are on the increase. But they have trapped seawater, leading to the flooding of inter-tidal zones – a vital habitat to wading birds, such as redshanks and avocets, which feed on invertebrates. It is estimated that salt marshes in Britain are disappearing at a rate of two square miles every five years. Environmentalists have now successfully campaigned for the "managed retreat" of flood defences to help restore the marshes. At Freiston, a sea wall completed in 1982 has been taken down on the orders of English Nature and will be replaced at a cost of £5m by a defence further inland. Dr Ian Patterson, English Nature's regional policy officer, said: "This is an enormously exciting stage of the Britain's biggest-ever salt marsh creation project. If all goes well, we should see the new salt marsh established during the next six years." Story time! Taken from the Independent
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**Student activity** - Coastal management on the Holderness Coast Write a report on future strategies for coastal protection. You need to consider economic, social, political and environmental issues. You should use the information in tables C and D in your text book (pages 163 & 164) to draw up a cost benefit analysis to justify the economic planning as your budget is limited – remember the council only have £4 million! It is likely that hard defences will be used for at least one area, so make sure you state the initial costs involved as well as any future maintenance. You can suggest one approach or a combination of options (hard/soft/managed retreat). Make sure you give reasons for you decisions and why you rejected the alternative strategies for each area. If there are any limitations that need to be taken into account with your chosen option(s) then also make this clear in your report. If it helps, diagrams may be used.
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Holderness Coastline Report
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