Holderness Coast: A multi-use area

A multi use areas is n area which offers a range of social, economic and environmental activities.

Easington Gas Terminal – provides 1000 jobs and 25% of UKs gas supply.

Humber Estuary: off-shore & on-shore wind turbines use strong winds to generate renewable electricity.

Bridlington – provides retirement homes with sea side views.

Human Activities Economic Activities

• Improved Transport• Rising living standards• Range of jobs (e.g. Eastington for industry,

Bridlington for tourism).• Tourism (scenery and wildlife) (e.g

Flamborough Head and Spurn Head)• Attractive place to live (e.g. Bridlington –

views of the sea)• Second homes/retirement (e.g.

Bridlington)

• Improved Transport and Communication• Available space (e.g. Hull for development

of industry and housing)• Large workforce (e.g. Hull which employs

5000 people in its dockland)• Natural Resources (e.g. fish in Hull, gas in

North Sea piped to Easington)• Tourism (e.g. Hornsea, Bridlington, Various

caravan and camping sites along the coastline)

Why have coastal areas developed?

Hull – Every year, 13 million tonnes of imported cargo pass through the port which employs 5000 people. Fishing industry lands fish at Hull docks.

Flamborough Head – stunning scenery and birds attracts tourists to visit.

Holderness Country Park – provides tourists with a large fishing lake and a dog walking area. Guests can stay in either log cabins or caravans.

How is development along the coast

damaging the local environment?

Cliff top developments have made the cliffs unstable which has increased rates of erosion.

Some animals and birds have choked on litter on beaches from tourists.

Industrial units and factories have polluted the sea causing death of aquatic life and thus disrupting food chains.

Coral reefs (e.g. St Lucia) are being damaged from tourists collecting souvenirs and anchors from fishing vessels.

Protection Scheme How does it protect the coastline?

Heritage Coast atFlamborough Head

-Encourages the use of public transport which reduces cars, congestion, noise and air pollution- farmers receive extra money through grants if they farm in a way that protects the environment and wildlife biodiversity (range of species)- footpath erosion is reduced by encouraging people to stay on paths through signage

Yorkshire WildlifeTrust at Spurn and Flamborough Head

-Organises seasonal beach cleans at two locations. All rubbish is separated out and recycled where possible which promotes sustainability-Helps to prevent millions of marine animals, birds, turtles and fish dying each year as a result of entanglement or eating litter floating around in the sea or beach.-Keeps beaches tidy which encourages tourists back into the area.

Greenbelts around Bridlington and Hull

-they have prevented new houses and industries from being built land ideal for farming land.-fewer development on cliff-faces has reduced the pressure on cliffs making them more resistant to erosion and weathering.-stopped woodlands and hedges being removed allowing for ecosystems to continue to flourish.

Marine Conversation Sites (MCS)

-The MCS has helped reduced overfishing to protect fish stock numbers from further declining. In the future, it is hoped that fish populations will increase.-The MCS also prevents sand dredging of the sea bed which can damage nesting sites of many fish.

How can we protect the coastline?

Conflicts of Interest : Different coastal users who make problems for each other.

•Oil refineries of S. Humber pollute water for local fishermen.

•Ships coming up R. Humber cause danger for tourist wind-surfers & jet skiers

•Wind turbines at Easington can kill migrating birds using Spurn for migration.

How is development affecting the environment?

Sea defences along the Holderness Coastline have stopped the movement of sediment to Spurn Head, an important habitat for numerous rare birds .

Footpath erosion at Flamborough Head due to high tourist numbers.

Diesel/oil spillage from the tankers may affect marine life; noise from tankers

Erosion and Weathering

Constructive and Destructive Waves

Constructive Waves Destructive Waves

Strong Swash, Weak Backwash Weak Swash, Strong Backwash

Deposits rather than erode Erodes rather than deposits

Low wave height (less than 1 metre) High wave height (more than 1 metre)

Low wave frequency High wave frequency.

Swash is the movement of water up the

beach

Backwash in the movement

of water down a beach

What determines the strength of a wave?- Strength of the wind- How long the wind has been blowing- The distance between the ocean the wave has

crossed (fetch)

Key Terms:Erosion – the wearing away of rocks by the action of the sea and their removalWeathering – the breaking up of rocks in situ by the action of the weather, chemicals and biology.

Erosion Weathering

AttritionEnergy from breaking waves causes rocks and pebbles to smash into each other They eventually break down into smaller and rounder pieces

AbrasionMaterials, like boulders, pebbles and sand are hurled against the cliff by breaking waves. This causes undercutting and the breaking up of rocks.

Hydraulic ActionWater is thrown into cracks within the cliff by breaking waves. Air inside the cracks is squashed by the water and the pressure inside increasesWhen the wave sinks back, the pressurised air expands explosively. This causes the rocks to shatter so the cracks slowly become bigger and deeper.

Wetting/dryingConstant wetting and drying causes rocks to expand and contract, resulting in surface cracks and weakening of the rock.

Freeze thaw WeatheringWater gets into cracks in rocks and expands as it freezes, putting pressure on the surrounding rock.

CorrosionCarbon Dioxide dissolves in rainwater, producing acid rain. This reacts with minerals inside certain rocks (e.g. limestone), causing them to be weakened and easily dissolved.

Erosion on Hard Coastlines

1) A cave is formed when hydraulic

action widens the joints in the rock

over time.

2) An arch is formed when hydraulic action

and abrasion continue to erode the backwall of a

cave all the way through the headland.

3)A stack is formed when the roof of the arch is weathered by freeze thaw action. This weakens it causing to collapse as a rock fall due to gravity.

4) Overtime, the base of the stack is eroded by abrasionwhich then topples over in a storm to form a stump.

Headland

Hard Coastline: Cave, Arches and Stacks

Hard Coastline: Headlands and Bays

Hard Coastline: Wave cut notch and wave cut platform

1) Hard (e.g. chalk) and soft rock (e.g. boulder clay) are at right angles to the coastline.

2) Soft rock is eroded at a faster rate by hydraulic action and abrasion.

3) Over time, a bay is formed within the soft rock. The shape of the coastline reduces the energy forming constructive waves. This allows beaches to form.

4) As the headland juts out to sea, it receives the full force of the waves energy. This allows the headland to be eroded slowly over time.

1) Erosion from the sea (i.e. abrasion

and hydraulic action) start to

undercut the cliff base.

.

2) The top of the cliff is weakened by freeze thaw weathering.

3) This wave cut notch increases in size until the weight of the cliff can no longer be supported.

4) Cliff collapses due to gravity as a rockfall.

5) The cliff slowly retreats back leaving a wave cut platform behind.

Erosion on Hard Coastlines

Erosion on Soft Coastlines

Process:Slumping is a rapid movement of boulder clay that occurs on a curved slip plane.

It happens when water percolates (soaks into) into the boulder clay until it becomes saturated with water making it heavy. The weight of the cliff above it forces the rock down towards the sea as a mud flow.

Landforms:A step like cliff face is present after the slumping has occurred. Vegetation (originally from the cliff top) will also be present in patches on the cliff face.

Process:Freeze thaw weathering is when water enters cracks between rocks and freezes. This causes the water to expand which puts pressure on the surrounding rocks. Over time, it weakens the rock causing it to break up. This causes rock to fall from the cliff face due to gravity as a rockfall.

LandformsA scree slope of fallen rock is formed at the bottom of the cliff face.

ROCKFALLS

SLUMPING

LANDSLIDESProcess:A landslide is a rapid movement of boulder clay that occurs on a slip plane that is parallel to the cliff face.

It happens when erosion from the sea undercuts the base of the cliff. This destabilises the cliff face causing the clay to slide down the cliff as a landslide.

Landforms:An accumulation of sediment remains at the base of the cliff which is known as a scree slope.

How are beaches formed?

How are spits and bars formed?

Swash Aligned BeachWaves approach the coastline and then break in parallel to the coastline

Swash and backwash move sediment up and down the beach.

Creates an even profile along the shoreline

During storms, berms(ridges of sediment can form).

5) Backwash brings the material back down the beach again.

4) Material is picked up again and moved back up the beach as swash.

1) Prevailing wind direction moves waves onshore at an angle.

2) Swash moves the material up the beach at an angle.

6)The sediment moves in a zig-zagmotion along the beach. Over time, large amounts of sediment are moved along the beach.

3)Backwash moves the material straight back down the beach to the sea.

How is a spit formed?

1. Waves carrying material are blown in the direction of the prevailing wind.

2. Longshore drift moves material along the coast.

3. Where the coastline changes direction, material is deposited in water sheltered by the headland.

4. The material builds upwards and outwards to form a spit.

5. A mud flat starts to develop in the sheltered water behind the spit due to less erosion.

6. Secondary winds can cause the end of the spit to curve forming a hooked end

7. The salt marsh develops on the mud flat in the sheltered water.

How is a bar formed?

1. Waves carrying material are blown in the direction of the prevailing wind.

2. Longshore drift moves material along the coast.

3. Where the coastline changes direction, material is deposited in water sheltered by the headland.

4. The material builds upwards and outwards to form a spit.

5. The spit continues to grow across the bay area and joins to the headland to form a bar.

6. A lagoon is formed behind the bar. Over time, this is filled up with sediment to form land.

Drift Aligned Beaches (longshore drift)

e.g. Spurn Head, Holderness Coastline

e.g. Slapton Ley, Devon

Why are decisions made to manage coastal areas?

Some areas are protected from the effect of coastal processes.

Understand that not all areas can be/need to be protected.−− Consider the issues associated with the planning, decision making and management of shorelines.

There are different methods that can be used to protect coastlines from the effects of natural processes.

Describe the concept of ‘hard’ and ‘soft’ coastal engineering.

Use an example(s) to illustrate the methods and issues associated with:−− hard engineering – use of sea walls, rock armour, gabions, tetrapods, cliff drainage, groynes.−− soft engineering – use of beach nourishment, beach recycling, beach re-profiling Replenishing.

Explore the reasons why different methods of coastal management may be appropriate in different locations.

Environmental management protects some areas.

How can the management of coastal areas be increasingly sustainable?

The sustainability of coastal areas requires the whole of the coastal zone to be managed effectively.

• Explore the idea of Integrated Coastal Zone Management (ICZM) by looking at one example of a coastal area in relation to its economic and environmental sustainability. Consider:−− the pressures on the area−− the strategies being used to reduce the pressures and ensure the long-term sustainability of the area.

Protecting coastal areas from the increasing threat of rising sea levels will require the development of different approaches

• Investigate one example of the use of managed realignment (retreat).−− Describe the methods used.−− Explain how they operate to protect the coastal area from flooding.−− Evaluate the significance of the methods in relation to the increasing risk of coastal Flooding.

Some areas are in greater need of protection than others. For

example there are a variety of reasons specifically economic and

social (socio-economic) why seaside towns need to be protected.

They are places where people live and they are also places where

money can be made specifically through tourism. Towns such as

Bridlington, Hornsea and Mappleton are in greater need of prrtection

than the farmland inbetween, the Easington Gas Terminal also

needs protecting because it is so important in providing gas for the

UK. Locally it also provides jobs.

The whole of the Holderness coast is vulnerable to erosion as it is

made of soft rock. This means decisions are made about which bits

to hold the line and which areas will have to be allowed to erode

back.

The Shoreline Management Plan SMP does this for the UK.

There are 4 Management Options

for each section of coastline:

No Active Intervention (do

nothing – and let the coast erode)

Hold the line (intervene to keep

the coastline where it is at present)

Advance the Line (build defences

further out from the existing

coastline)

Managed realignment (develop

defences further inland and permit

some coastal flooding)

The aim of the Shoreline Management Plan is to identify which

areas of coast require protection, and which don’t. By looking at

the coast as a whole (a system) planners can make sure that

any changes to one part of the coast – will affect other parts in

a planned way and not give surprise effects.

Coastal Management

Hard EngineeringControlled disruption of natural processes by using man-made structures

Advantages - Protects the base of cliffs, land and buildings against erosion. Can prevent

coastal flooding in some areas.

Disadvantages = Expensive to build. Curved sea walls reflect the energy of the waves

back to the sea. This means that the waves remain powerful. Over time the wall may

begin to erode. The cost of maintenance is high.

Advantages = Prevents the movement of beach material along the coast by longshore drift.

Allows the build up of a beach. Beaches are a natural defence against erosion and an

attraction for tourists.

Disadvantages - Can be seen as unattractive. Costly to build and maintain.

Advantages - Absorb the energy of waves. Allows the build up of a beach.

Disadvantages = Can be expensive to obtain and transport the boulders.

Advantages - Easily installed. Cheaper, than sea wall, deflects wave power

Disadvantages - Can be eroded from below easily, needs frequent repair, not very

attractive

Advantages - Easily installed, cheaper than sea wall

Disadvantages - Not very attractive, needs frequent checking & repair, not easy for

people to get over to get to beach, may contain rats nests

Revetment

Tetrapods

Popular option in Japan – seen to be effective

Can be built on-site

Allows some waves through – so less ‘reflected’ wave damage

Reasons behind the Beach Replenishment scheme at Pevensey

Reason 1 : Almost all of the 150 wooden Groynes had deteriorated and either needed repair or replacement.

Both would be very expensive and use a lot of hardwood – which isn’t a sustainable solution. They were

removed in 2007.

Reason 2 : The beach environment has many valuable plant species and these needed to be protected and

encouraged to thrive.

Reason 3 : There are many coastal homes looking out over the beach – and their protection, but also their

views needed preserving.

Beach Replenishment

Sand and gravel is hoovered up by a dredger ship off the

coast, and sprayed onto the lower beach at high tide.

At low tide, bulldozers push the material up the beach to raise

the height of the beach

This takes place 3 times a year – in early Autumn after the

holiday season, in January before the main winter storms, and

at Easter just before the holiday season and to correct winter

storm damage to the beach.

Soft EngineeringWorking with the natural processes of sea and sand in a more environmentally sustainable way. Using the

natural processes to bring about an intended effect.

Beach Re-Cycling

Advantages - Adds to tourist amenity by making bigger beach, attractive, works with the natural processes of

the coast

Disadvantages - Needs frequent renewal of more sand, does not protect cliff face from winter storm waves.

Beach Re-Building

Advantages - Adds to tourist amenity by making bigger beach, attractive, works with the natural processes of

the coast

Disadvantages - Needs frequent renewal of more sand, does not protect cliff face from winter storm waves.

Beach Re-profiling

This means changing the gradient of the beach to

the best one for absorbing the wave energy.

Winter storms remove lots of the lower beach with

their strong backwash.

Bulldozers spread the sand evenly across the

beach in Spring to create a more even profile –

which is better at absorbing wave energy.

Re-profiling

Sea Level Rise, Global Warming and Managed Retreat

Climate change is putting increasing pressure on coastal defences as sea levels rise and are predicted to rise

further into the future (Holderness = 50cm rise predicted in 50 years)

Management options for protecting coasts from rising sea levels consist of :

Do nothing – let the sea flood onto land

Move entire communities inland onto higher land

Build higher defences with sea walls & embankments

Plan for Managed Retreat (coastal realignment) 'THIS IS SEEN AS THE PREFERED OPTION

The Humber faces increasing problems from rising sea levels.

The existing defences are already starting to become inadequate was breached by a storm surge in 2003.

The engineers had to decide whether to repair the breach, or put in a longer term solution.

Sea level rises along the Humber estuary are forecast to continue over the next century

Managed realignment involves the construction of new sea walls at a location behind existing sea walls to

create parcels of land that can be flooded to create new inter-tidal environments.

Benefits:

The new mudflats and salt marsh (created where the defences are breached – see photo) will help

protect the new sea wall

They will offer additional protection to the property to the south

The scheme aims (still too early to assess) to bring back bird habitats which were lost to previous

development, improve flood defences on the island and create new leisure opportunities

Costs:

The scheme cost taxpayers £7.5 million

Sediment (mud) and vegetation (salt marsh) has not been immediate

Wallasea Island, Essex

Location:

Wallasea Island is a low-lying coastal island

formed at the confluence of the Rivers Crouch

and Roach in Essex.

What has happened?

With the coastal defences in the north of the

island crumbling away, the government

decided to realign (change the shape of) the

northern part of the island by constructing a

new embankment (wall) inland (further south)

and allow the sea to further break through

(breach) the old sea defences.