3.11 Managing coasts in a holistic way Flashcards
(32 cards)
How much of the Holderness coastline is protected?
only 9.2km are protected by hard engineering structures out of 85km
What is a cost benefit analysis ?
It is carried out before a coastal management project is given the go ahead. Costs are forecasted and then compared with the expected benefits
The costs and benefits can be either tangible or intangible
What are tangible costs and benefits?
where costs and benefits can be given a monetary value
What are intangible costs and benefits?
where costs may be difficult to access but are important (e.g. the visual imapact)
What defences have been put in place at Hornsea?
Concrete sea walls, groynes and a rock armor
What are the impacts of the defences at Hornsea?
The groynes trap the sediment and maintain the beach at Hornsea , but Mappleton downdrift has been starved of sediment as a result. There, rapid wave attacks have eroded the cliffs, so that by the 1990s, nearly 4m of the cliff were being eroded each year
What are the defences at Mappleton?
Two rock groynes (costing £2 million) were built in 1991, with the aim of preventing the removal of the beach by longshore drift. Rock armor was also used
What were the impacts of the defences at Mappleton?
At Cowden, 3km south of Mappleton, the resultant sediment starvation caused increased erosion of cliffs
What defences have been put in place at Withernsea?
A straight sea wall was built in 1875. However, over time, wave energy scoured the base of the wall- causing it to collapse. So, in the 1990s, the straight wall was replaced by a curved wall- at a cost of £6.3 million
What have been the impacts of the defences at Withernsea?
The waves are now noisier when they break against the wall and the promenade is smaller
The views from the sea-front hotels have also been restricted. Some tourists find the rip-rap at the base of the sea wall unattractive
What is integrated coastal zone management?
This means that complete sections of the coast are now being managed as a whole- rather than by individual towns or cities. This is because we now know that human actions in one place will affect places further along the coast in sediment cells
When was the ICZM at the Holderness introduced?
2002
What was done with the Holderness ICZM after it was established?
it was used to help develop the Flamborough Head to Gibraltar Point Shoreline Management Plan (SMP).
What is the SMP at the Holderness?
The Flamborough Head to Gibraltar Point SMP sets out the policy for managing the coastline and responding to ccoastal erosion over the next 100 years. It assesses potential erosion and flood risks, and then identifies sustainable coastal defence and management options, which takes into account the needs of human, natural and historic environments.
What are the four options for coastal action?
Hold the line- maintaining the current position of the coastline (often using hard engineering methods)
Advance the line- this involves extending the coastline out to sea (by encouraging the build up of a wider beach, using beach nourishment and groyne construction)
Managed retreat/strategic realignment- allowing the coast to retreat but in a managed way. It involves the deliberate breaching of flood banks built to protect low quality farmland from flooding (creating a salt marsh environment)
No active intervention- allow the sea to erode the cliffs and flood low lying land
Why is the policy decision at Hornsea to hold the line?
-it is a regional economic centre with a population of 8,500
-important historic sites and Southorpe medieval village
-inland is Hornsea Mere: a very important lake habitat for birds that is a site of special scientific interest
What was the cost benefit analysis like at Mappleton?
it was protected at a cost of £2 million (in a scheme supported by EU funding), despite the village only being valued at £650,000. If the policy decision was being made today, it may well have not of been defended. In the 2010 SMP, the economic case for defending Mappleton was described as marginal.
The reason it was built was due to pressure from communities as houses on cliff road were falling into the sea
How are areas with ‘no active intervention’ along the Holderness likely to be affected along the coastline?
-up to 400m of land could be lost by 2105
-in the North Cliff area of Hornsea, some properties could be at risk by 2055
-by 2105, the main coastal road is likely to have been destroyed by erosion , south of Rolston and south of Mappleton
-by 2055, around 200 hectares of farmland and 32 properties are likely to have been lost to erosion
What are the features of a ICZM?
-entire coastline is managed
-recognizes the importance of the coast to people’s livelihoods and the need for sustainable management
-plans for the long term
-adopts adaptive management (changing policies if threats change)
-works with natural processes rather than against them
-uses participatory planning
Involves multiple stakeholders-may be across political boundaries
What are the factors that determine which policy is put in place at a coast?
-economic value
-technical feasibility of engineering solutions
-the cultural and ecological value
-pressure from the communities
What is an example of a section of the Holderness coast being protected due to economic value?
the nationally important natural gas terminal at Easington will be protected, as will Hornsea
What is an environmental impact assessment?
it aims to identify:
-short term impacts of coastal environment construction
-long term impacts of building new sea defences
What are some examples of assessments which contribute to the EIA?
-impact on water and sediment flow, which can affect marine ecosystems
-impacts on water quality
-possible changes to flora and fauna
-air quality and noise pollution
What is the management strategy considered as at Spurn Head?
Abandonment