GCSE AQA A Geography
Case Studies
to help you
revise
for the
Physical
paper.
One question - Section A
One question - Section B
One question
-Answer the question from
The Restless Earth
Answer the question from
Ice on the Land
OR
The Coastal Zone
Answer the Section B question
from
Ice on the Land
OR
The Coastal Zone
which you haven’t already
answered.
Unit 1- Physical Geography Case Studies
Section A
The Restless Earth
Section B
Ice on the Land
Section B
The Coastal Zone
Fold mountains – The Alps
The Mer de Glace to show
retreat of a glacier.
Landform created by erosion:
Durdle Door in Dorset for an arch
Old Harry Rocks for stumps
Volcanic eruption
-Montserrat LEDC
La Plagne for Glacial Winter
Sports (in The Alps)
Landform created by deposition:
East Head Spit
Slapton Sands – Bar
Chesil Beach, a swash aligned beach and
joining to the Isle of Portland in Dorset
-tombolo
Supervolcano - Yellowstone
National Park- USA.
Mer de Glace, Chamonix for all
year round tourism (also in The
Alps)
Cliff collapse - Barton-on-Sea, Dorset
Example of an earthquake
-Haiti as LEDC
Managing tourism: Belle Plagne
and Chamonix in The Alps
Rising sea levels - the Maldives
Example of an earthquake –
Chile as MEDC
Effects of climate change – The
Alps
Hard and soft management – West
Wittering beach and East Head Spit
Boxing Day Tsunami
-West Coast of Indonesia/
Indian Ocean
Coastal habitats – East Head Spit
Managed retreat – Medmerry
Scheme, West Sussex.
The Restless Earth
Fold Mountains – The Alps
Where?
Central Europe, the Alps form the border between Italy and the neighbouring countries of France, Switzerland, Austria and Slovenia. The highest peak is Mont Blanc near the French-Italian border at 4810 metres.
When?
The last 60 million years. However, Glaciation in the last 100,000 years has sculpted the landscape further with frost-shattered peaks and deep U-shaped valleys.
Why?
The collision between the African plate and the Eurasian plate. Limestone sediments formed in the Geosyncline were folded up into the peaks of the Alps
What?
The diagram shows this. Sedimentary rocks form in a geosyncline (large depression in which sediment has been deposited in it.). The sediment turns into rock (sedimentary rock such as limestone). The plates begin to move and squeeze the rocks. This causes the rocks to fold producing anticlines (upward folds) and downward folds (synclines).
Physical problems for people
• Relief – mainly high and steep. There is little flat land for farming and building settlements.
• Climate – with increasing height it gets colder, windier and wetter and more precipitation falls as snow. Often impossible to grow crops at high levels. • Soils – mountain soils are typically stony, thin and infertile.
• Accessibility – roads and railways are expensive to build; travel on them is frequently disrupted by rock falls; avalanches and bad weather. High mountains in inland areas such as the Himalayas are the least accessible of all.
Human activities – How have people adapted to the landscape?
The valleys are used for roads and railways.
1. Farming
• Farms located on sunnier and warmer south-facing slopes of valley sides.
• Pastoral dairy farming is prominent, use a system called ‘transhumance’ which is the seasonal movement of animals. In summer, the cattle are taken up to the High Alp (saeter) to graze, in winter the animals return to the farm on the valley floor, where they are kept in cattle sheds.
• Changes to traditional farming system have been made – pipes are used to bring milk to the co-operative dairies down on the valley floor in the summer.
• Farmers buy in additional feedstuffs, so that they and their cattle can stay on the valley floor farm all year.
Soils are deep and fertile in the valley floor, so arable (crop) farming is done.
2. Forestry
Coniferous trees cover many of the slopes. Wood, as a plentiful local resource has always been the main building material and winter fuel.
Human activities continued … 3. Tourism
Winter tourism (examples of resorts are La Plagne and Chamonix)
Glaciated valleys have produced steep slopes. The height has enabled a long snow season.
• Snow for skiing and other winter sports; in between the days of heavy snowfall there and many sunny, crisp and clear days.
• Flatter land on high-level benches (high alp) for easy building of hotels, restaurants, ski lifts and other facilities.
• Steep slopes above the resorts for ski runs amid great mountain views.
Summer tourism (The Montenvers train taking people to the Mer De Glace near Chamonix is an example of this.)
Hiking, mountain biking, abseiling etc. Warm temperatures ideal for this.
• Large glacial lakes on valley floors.
• Beautiful mountain scenery with snow capped peaks.
4. Hydro-electric Power (HEP) and Industry
• The steep/deep U shaped valleys created by glaciation, high precipitation and summer melting of glaciers produce fast flowing rivers that are ideal for generating HEP, enabling industry to be set up on the valley floor.
• The narrow valleys are easy to dam and there are reservoirs in which to store water.
• Cheap HEP is used by industries which require high input of electricity, such as sawmills and fertiliser manufacturing.
• Some of the electricity is also exported to other regions to supply towns and cities.
The Restless Earth
Volcanic eruption - Montserrat LEDC
Where/When?
The volcano (Soufriere Hills) started erupting in 1995 for the first time in 350 years. However, the big eruption came in June 1997.
Montserrat is an island is situated in the Caribbean and 12 miles long x 7 miles wide. Much of the population is poor and relies on farming. Before the eruption of 1995, over 12,000 people lived on the island but less than 5,000 do today.
Causes
•On a destructive plate boundary. The Atlantic plate being subducted under the Caribbean plate .
• Was a dormant volcano, hadn’t erupted for more than 200 years. It was unexpected.
Primary Effects
• Large areas were covered with volcanic material. Plymouth, capital city, buried.
• Huge pyroclastic flows over 500⁰C – 3 main ones came down ‘Mosquito Gut’ destroying 20 villages and 2/3rds .
• 19 killed and 7 injured..
• 50% of Montserrat uninhabitable.
• Loss of houses, farms , schools, hospitals, the airport , vegetation and farmland, animals and crops.
Secondary Effects
• Fires destroyed many buildings.
• Infrastructure destroyed lead to no trade.
• Initially loss of tourism, however, gradually increasing again.
• Population decline 8,500 of the islands 12,000 have left since 1997 leaving 3,500.
• The need to rebuild giving stress for people.
• Volcanic ash has improved soil fertility.
• The need to rely on aid from UK.
What is the future for Montserrat?
Tourists began to come back to the island by 2005. Little Bay has developed as the new capital, with the harbour helping trade. However, the volcano still rumbles on...
Short term responses
• People were evacuated from the south to safe areas in the north in August 1995.
• April 1996, Plymouth was evacuated, and an exclusion zone set up, saving lives.
• People left the island completely.
• Temporary infrastructure built –roads and electricity supplies.
• The UK provided £17 million of emergency aid (Montserrat’s a British Overseas territory including money for temporary buildings (some built to house evacuees) and water purification.
• Local emergency services provided support units to search for and rescue survivors.
• Charities set up temporary schools, and sent emergency food for farm animals.
Long-term responses
• Some people have returned to the island. 2010 population was 5,000.
• Island’s population structure changed – many younger left and didn’t return; many older either never left or came back.
• The British government has spent over £200 million helping Montserrat restore electricity and water, build a new harbour in the north of the island at Little Bay, a new airport and roads.
• A risk map was created and an exclusion zone is in place. The south of the island is off limits while the volcano is still active.
• The Montserrat volcano observatory was set up in 1996 to try and predict future eruptions.
The Restless Earth - Where is the next super-eruption suggested to be?
Supervolcano - Yellowstone National Park- USA.
Where is the next super-eruption suggested to be?
Yellowstone National Park is in the NW of the USA in the state of Wyoming, although it extends slightly into Montana and Idaho. It was the first National Park in the World and is a very volcanically active area due to the ‘hot spot’beneath it.
Characteristics
• Supervolcanoes are as their name suggests, super.
• They are much larger than normal volcanoes and when they erupt, they can change the many characteristics of Earth.
• They will eject at least 1,000km3 when they erupt compared to a normal volcano, which release around 1km3 of ash and rock.
• Unlike regular volcanoes, they do not have the usual cone like structure, rather they occur in large depressions called calderas (Greek for cauldron).
Calderas are formed when:
the magma chamber of a supervolcano collapses after an eruption leaving a large bowl shape in the ground.
The magma chamber under Yellowstone is currently 80km long, 40km wide and 8km deep so if and when an eruption occurs, the caldera that is left will cover roughly the same area as London.
How big are they?
Look at the diagram. Look how small the circle representing the size of the Mount Saint Helens eruption is compare to the VEI 8 eruptions. VEI stands for Volcanic Explositivity Index. Like the Richter scale it is logarithmic – each point on the scale is 10x greater than the previous. To be a VEI 8 – super eruption – 1,000km³ needs to be ejected.
Likely Effects
When considering the Yellowstone supervolcano, one of, if not the largest supervolcano in the World, the effects could be catastrophic and change the face of the planet as we know it.
Currently, there are 3,000 earthquakes in the area each year and along with various other changes, it has led scientists to worry that an eruption could occur soon, although this is very unlikely.
An eruption in the next couple of centuries is NOT
expected. Some of the effects are predicted to be:
• 10,000km3 of land erupted.
• 25 mile high ash cloud.
• Everything within 1,000km of the eruption will be destroyed or killed by ash and lava flows.
• Magma thrown 50km up into the atmosphere.
• The ash in the atmosphere could lower global temperatures by 20°C.
• 1,000 miles away, the layer of ash that will be deposited on the ground will be up to 10ft thick.
• Two thirds of the USA will be uninhabitable.
• 87,000 could be killed.
• 1 in 3 people affected would die.
• Huge impact on transport, energy, electricity, agriculture, and general production.
• The UK would receive the ash cloud 5 days after the eruption.
• The global economy will be placed under huge pressure and likely collapse due to the damage to the USA.
• The amount of ash in the atmosphere would block out solar radiation and result in freezing temperatures.
• Crops wouldn’t grow, economies would collapse and it is believed that society would not survive.
The Restless Earth
Example of an earthquake - Haiti as LEDC
When? 12/1/2010
Where?
Haiti, with the capital Port-au-Prince hit very badly. Epicentre 13km underground, 25km from Port-Au-Prince.
Why?
Destructive plate boundary where the Atlantic plate subducts the Caribbean plate (same as Montserrat), but the earthquake was actually along a fault line caused by this pressure.
In fact, the earthquake was a strike-slip event, which is like what happens at a Conservative margin.
Primary effects
• About 220,000 killed and 300,00 injured.
• Port damaged, roads blocked .
• 8 hospital s or health centres in Port-au-Prince collapsed or damaged.
• Many government buildings destroyed.
• About 100,000 houses destroyed and 200,000 houses damaged in Port-au-Prince and surrounding area.
• About 1.3 million people displaced .
Secondary effects
• 2 million without food and water.
• Looting – police force collapsed .
• Damage to port and road prevented medical supplies being distributed effectively.
• Disease in tented camps. Mass graves as people were left on the streets.
• Power cuts .
Short term response
• The port and main roads were damaged, and the airport couldn’t cope.
• Supplies weren’t distributed effectively.
• American engineers tried to clear the worst of the debris in the port so that ships could unload the aid.
• The USA also sent 10,000 troops and $100 million in aid.
• Bottled water and purification tablets were provided.
• Field hospitals were set up.
• 235,000 people moved from Port-au-Prince o less damaged cities.
Longer-term response
• Rebuild homes to a better standard.
• Rebuild port. And bring Haiti’s road, electricity, water and telephone systems up to standard.
• Still reliant on overseas aid.
Haiti – preparation for and protection against earthquakes.
• Haiti wasn’t prepared in January 2010, as there hadn't been any earthquakes in living memory.
• The government was weak.
• There was little money.
• Port-au-Prince was overcrowded with 2.5 million people.
The Restless Earth
Example of an earthquake - Chile as MEDC
Chile is not the richest, but it is more affluent than Haiti. When hit by an 8.8 earthquake its impact was far less than the 7.0 at Haiti.
When?
27/2/2010
Where?
115km from the city of Concepcion the coast of Chile .
Why?
Nazca plate subducts the South American plate at a destructive plate boundary.
Primary effects
• 500 killed.
• 12,000 injured.
• 500,000 homes damaged.
• Bridges and roads destroyed.
• Santiago’s airport slightly damaged.
Secondary effects
• Power, communications and water supplies lost .
• Tsunami.
• Fire at a chemical plant near Santiago.
Short term response
• They responded very quickly as they are prepared for such events. The President insisted on rapid analysis and asked for help from countries within a few hours.
• The Route 5 highway was temporarily repaired the day after the earthquake. Aid was therefore able to get where it was needed
• 90% of homes had their power restored within 10 days.
• A national telethon raised $60 million – used to build emergency shelters for the homeless.
Longer-term response
• Housing reconstruction plan for the 196,000 households affected.
• The economy was quite healthy, so they weren’t reliant on foreign aid.
Chile – preparation for and protection against earthquakes.
• Chilean government well prepared February 2010, following the one in 1960 when they weren’t.
• Buildings since 1960 built to withstand earthquakes – reinforced concrete columns, strengthened by a steel frame.
• 2002 – plan created setting out responsibilities of central and local government. Worked well in 2010.
• Regular anti-disaster drills.
• Chileans know to “Drop, cover, hold” i.e. Drop to the ground Take cover
The Restless Earth
Boxing Day Tsunami - West Coast of Indonesia/ Indian Ocean
When?
26/12/2004
Where?
Indonesian coast near Banda Aceh.
Why?
9.3 Earthquake in Indian Ocean, off the coast of Sumatra, Indonesia.
Subduction of Indo-Australian plate under Eurasian plate.
The tsunami then moved as a series of ‘ripples’ across the Indian Ocean, building in height to produce massive waves as it approached land .
Impacts
Indonesia: 70% of some coastal populations killed or missing.
Sri Lanka: S and E coastlines ravaged. 400,000 people lost jobs in Sri Lanka due to loss of tourism and fishing boats.
India: SE coast worst affected. Arable land was destroyed by the salt water
Thailand: W coast severely hit. Tourism industry suffered greatly. 1,700 foreign holiday makers died.
About 290,000 people died in total.
Immediate responses
• Clean water, food, tents and plastic sheeting arrived as aid
• $7 billion donated worldwide for the affected countries
• £330 million donated by people of the UK
• UN World Food Programme provided food aid for more than 1.3 million people
Longer term responses
Countries around the Indian Ocean hold tsunami drills.
Longer term responses continued
• A Tsunami warning system was installed in the Indian Ocean; warnings are sent to each country and these are relayed on radio, TV and email. Warning bells/loudspeakers on mosques will also provide warnings.
• There are also natural ways of providing protection through allowing mangroves to develop. These mangrove swamps absorb wave power, but many have been cleared to make room for hotels. The restoration of these will provide some protection.
Ice on the Land
The Mer de Glace (Sea of Ice) to show how a glacier is changing / retreat of a glacier.
Where?
Key facts
The Mer de
Glace-• Is the highest glacier in France
• 7 Km long; 200m deep.
• Flows NNW from Mt Blanc towards Switzerland.
• Is close to Chamonix.
Since 1850, it has become shorter and thinner.
In 1970’s and 1980’s it advanced 150metres. It is now retreating again by 30metres a year. (Already 500metres shorter than it was in 1994)
Evidence of
retreat-• 19th Century paintings:
• Old maps from a century ago
• Debris left by the glacier on the valley’s floor and sides.
• Aerial photographs and satellite images.
Why is the glacier retreating?
The Mer de Glace is retreating due to climate change. Temperatures are 1⁰C higher than 100 years ago, and 3⁰C higher above 1,800 metres. Combined with drier winters (i.e. less snowfall) the glaciers are melting away.
Ice on the Land
The Mer de Glace (Sea of Ice) to show all year round tourism
Where?
Key facts
The Mer de
Glace-• Is the highest glacier in France
• 7 Km long; 200m deep.
• Flows NNW from Mt Blanc towards Switzerland.
• Is close to Chamonix.
Chamonix has Europe’s highest mountain – Mont Blanc.
It has a permanent population of 10,000, but this can swell to 100,000 in winter (snow sports) and 130,000 in summer.
The reason people go in the summer is the beautiful countryside, hiking, walking, mountain biking, shops, restaurants and the Mer de Glace.
The Montenvers train takes people to the edge of the glacier (pictured right). It was built in 1908. Once at the glacier, tourists can experience the ‘Ice Cave’ which has been carved in the glacier.
This has created conflict.
Many welcome tourism, whereas others do not.
Tourists may be in conflict with each other if one group wants peace and quiet and the other wants the lively nightlife and sport activities.
Conservationists do not like the damage being done to the environment. Many local people want further development as they can make more money.
Economic Impacts
Social Impacts
Environmental Impacts
• Thriving economy as a result of tourist spending.
• Tourism is all- year round. Demand for services is maintained throughout the year, creating jobs
• Young people stay when they leave education – many job opportunities .
• Traditional way of life changed – decline in local crafts and skills.
• Some tourist
developments e.g. ski slopes have increased risk of avalanches.
• Large amounts of water needed for the resorts for drinking/ snow making.
• Noise from machinery scares wildlife.
• Forest cleared for slopes- soil erosion and water cycle?
• Skiing damages vegetation underneath.
• An increase in vehicles has led to air pollution – this is often trapped in the Alpine valleys.
Ice on the Land
La Plagne for Glacial Winter Sports (in The Alps)
PLUS – Managing tourism in the Alps
Where?
La Plagne.
120 million visitors go to the Alps each year for winter sports such as bobsleigh, skiing, snowboarding, rock/ice climbing etc. La Plagne has tapped into this market.
When?
Built in 1960s.
Where?
French Alps, 2000 metres up.
Why?
To make money from tourism! I
t was a good location as the height guarantees snow from December to April (i.e. long season) and a glacier (Bellecote) which can guarantee skiing, even in the summer.
What other positives does La Plagne possess?
• Large selection of bars, restaurant and nightclubs..
• Variety of slopes for all abilities.
• Ski to doorstep.
• Not just skiing – other winter sports available like paragliding, husky sledding, snowshoeing, and sleigh riding. If you are adventurous there is the Olympic bob sleigh run!
Recent developments:
• Great access (train, 4 airports nearby and access to motorway network) made it very popular.
• It now has six villages all interlinked by a quality lift system.
• It has even been linked up to Les Arcs to produce a huge ski area.
• Expansion was done ‘in-keeping’ with the environment: buildings built in a traditional style, rather than just building ugly tower blocks.
Managing tourism in the Alps
LA PLAGNE/ BELLE PLAGNE CHAMONIX – RESPONSIBLE TOURISM (Please see previous 2 pages re Mer de Glace)
• New building built in traditional style (wood).
• Underground parking – ski to hotel and limits pollution in the resort .
• Some of the villages are above the tree line, so tree cutting not an issue .
• Avalanche fences built for protection.
• Part of the Vanoise National Park-conservation a key focus.
The council has developed a policy of ‘integrated tourism’, which educates and involves visitors and local people in the protection of the Alpine environment. It includes :
• System of avalanche barriers maintained.
• Avalanche awareness courses.
• Daily bulletins for tourists.
• Free public transport (reduce car usage) .
• Pollution from public transport reduced as buses are low emission.
• Encouraging local farming .
• Some hotels fitted with solar panels to heat water and systems to automatically turn lights off. CO2 emissions reduced.
Ice on the Land
Effects of climate change – The Alps
The Rhone Glacier in 1920
What?
The glaciers are retreating.
The Rhone Glacier in 2005
Why?
• Temperatures have risen by 1⁰C over the last century and has risen by 3⁰C over 1,800 metres in the last 40 years.
• The Mer de Glace is 500 metres shorter than it was in 1994.
• Winter snowfall is unreliable and the lower Alps is receiving less total snowfall overall.
These will cause real problems for glaciers.
Impacts Economic
• Some resorts will no longer be viable as Winter resorts- this is a real problem in the southern Alps.
• Fewer sightseers and ice climbers will be a problem in all resorts.
• Less tourism will result in less income for the area .
• However, the big, high-altitude resorts, should prosper as people are forced to go to them. They have the facilities and amenities already and the ability to make artificial snow.
• Agriculture could benefit from a higher snowline and warmer summers – a longer growing season.
Social
• Jobs could be lost if tourist numbers fall – higher unemployment.
• With no jobs, young people will leave to find work – change in the population structure .
• Services could decline, but the elderly that remain will demand more.
Environmental
• The Alps is a ‘fragile environment’, which h means it is easily damaged.
• A delicate balance exists, so the increase in temperatures/ loss of snow could mean that it is uninhabitable for some species.
• Less water, so river levels will drop that have their source in the Alps. More avalanches .
• Flooding from melting glaciers .
The Coastal Zone
Landform created by
erosion:
Durdle Door in Dorset for an arch
Old Harry Rocks for stumps
CAVES, ARCHES AND STACKS
A crack in a headland can be eroded- wave energy is usually strong there because the headland juts out.
This forms one or more wave cut notches/caves. Further erosion enlarges the cave and it breaks through the headland forming an ARCH.
The roof of the arch is often unstable and eventually collapses leaving a STACK or SERIES OF STACKS.
Areas with limestone or chalk geology are prone to this kind of erosion.
MAKE SURE YOU REFER TO ACTUAL NAMED PROCESSES HERE. Durdle Door is an example of an arch which will eventually become a stack.
Location: near Lulworth in Dorset.
Landform Type: Limestone.
Age: Jurassic 140 million years old.
Old Harry Rocks are an example of stumps. Location: Handfast Point, near Studland, Dorset.
Landform type: Chalk.
The Coastal Zone
Landform created by
deposition
: Swash and drift aligned
beaches
East Head
Spit
Slapton Sands –
Bar
Chesil Beach – a swash aligned beach and joining to the Isle of Portland in Dorset -
tombolo
Beaches
Swash Aligned beaches are where waves approach parallel to the shore and break with swash moving directly up the beach and the backwash returning directly back. These form wide beaches with an
even shoreline.
Ridges tend to form on beaches such as these called berms.
Example: Chesil Beach, Dorset. Drift aligned beaches
These form when waves approach the beach at an angle resulting in a swash moving diagonally up the beach and the backwash returning through gravity. These movements create longshore drift. These beaches
have an uneven profile-especially when groynes have been used to slow the longshore drift. Example: West Wittering, West Sussex.
Spits
Deposition also creates SPITS e.g. East Head Spit. Spits are beaches joined to the coast at one end.
At their seaward end shingle ridges form a series of recurves or hooks.
Spits often develop across river mouths or where the direction of the coastline changes abruptly.
Spits form by a process called LONGSHORE DRIFT.
Tucked away behind spits are quiet backwaters
that waves cannot reach, where tidal currents deposit fine silt and build up MUDFLATS and SALT MARSHES.
Bars
Deposition also creates BARS. The formation of Bars are very similar to that of Spits, but Bars join one part of the mainland to another. They seal off a body of water, forming a lagoon.
Bars tend to form in highly sheltered coastal environments as this allows sediment to build up more often that it is removed by tidal and river currents.
A good example of this is Loe Bar in Cornwall or Slapton Sands in Devon.
Tombolos
If a spit extends and joins up with an island then this is called a TOMBOLO. The best example of this is Chesil Bach joining to the Isle of Portland in Dorset.
The Coastal Zone
Cliff collapse - Barton-on-Sea, Dorset
Christchurch Bay near Bournemouth is constantly under attack from the sea. Cliffs are eroding 1-2 metres p.a.
Christchurch Bay is 16km long and parts are exposed to waves with a fetch of 3000km across the Atlantic.
The area is densely populated with coastal towns and resort areas e.g. Highcliffe,
Barton-on-Sea and Milford-on-Sea. Tourism is important, so cliff collapse is a major issue.
Why are the cliffs collapsing?
Marine processes: The base of the cliffs are being attacked by the waves (hydraulic action and abrasion). The large fetchresults in powerful, destructive waves.
Sub-aerial processes: Weathering is weakening the rock and then mass movements (slumping and rock fall) is leading to collapse.
Geology: Permeable sand lies on top of impermeable clay. During heavy rain the water collects above the impermeable clay and the sand becomes too heavy and collapses.
Human activity: Extensive building along the cliff top has resulted in too much weight on the soft cliffs and this has promoted collapse.
A large groyne that was built in 1938 to protect Hengistbury Head.
Unfortunately, this has prevented sediment from reaching the beaches along Christchurch Bay, which has promoted further erosion.
What are the impacts of cliff collapse at Barton-on-Sea? Social
Loss of homes.
House values go down – people can’t move. House insurance very expensive.
Dangerous to walk on the cliff tops.
Economic
Roads under threat.
Tourists may not visit (coastal protection works look ugly?) Dangerous? This impacts on local businesses (taxis, cafes, hotels etc.)
Cliff collapse looks unattractive.
Environmental
Cliff collapse exposes different rocks and fossils – interesting to scientific community. For example, the cliffs at Naish Farm holiday village are being allowed to erode for this reason as they are a Site of Special Scientific Interest (SSI)
At Barton-on-Sea, in Christchurch Bay, mass
movement is the main cause of cliff collapse but the
other factors on the left all play a part.
The Coastal Zone
Rising sea levels - the Maldives
RISING SEA LEVEL WILL HAVE IMPORTANT CONSEQUENCES FOR PEOPLE LIVING IN THE COASTAL ZONE Why are sea levels rising?
• The belief is that global warming is causing sea levels to rise.
• The heat is causing the ice caps to melt, which is releasing water into the oceans.
• In addition, the extra heat can cause thermal expansion of the sea too, making it higher.
• Estimates suggest that levels could rise between 30 - 140cm by the end of this century.
Effects of sea level rise
• Climate change is likely to raise sea levels and bring more rain in winter.
• There may be more winter storms.
• Coastal lowlands will be at increased risk of flooding and will cause more damage.
• Rates of coastal erosion are likely to increase.
• There will be increasing numbers of landslides of soft cliff coastlines because of higher rainfall and increased rates of erosion.
• Protecting coastlines from erosion and flooding will become more difficult and more expensive.
The Maldives
is a location at risk of sea level rise.
Impacts of coastal flooding on the MaldivesEconomic
Loss of tourism. Damage repair costs. Loss of agricultural land.
Social
Deaths.
Water supplies affected.
Traditional way of life lost as homes flooded and land lost. Loss of jobs.
‘Environmental refugees’.
Political
The government has to make policies to reduce the impacts of future flooding and erosion. The whole country could disappear!
They can do things like building more or better coastal defences, or they can manage the use of areas at risk e.g. stopping people living there. Political tension between the polluters and the Maldives – the Maldives are suffering, but they are not to blame for global warming.
Environmental
coral reefs will die as the water gets deeper. Ecosystems associated with reefs lost. Loss of habitats.
The Maldives is a collection of very low-lying islands. The highest point is only 2.4 metres above sea level. The beautiful landscape and white sandy beaches has resulted in 30% of the country’s GDP being created by tourism.
The Coastal Zone
Hard and soft management – West Wittering beach and East Head Spit
East Head is the sand dune spit at the eastern side of the entrance to Chichester Harbour. It is a stunning example of a natural and dynamic coastal feature which is of great interest to environmentalists and ecologists because of its fragile nature. It is an SSSI (site of special scientific interest) and a Ramsar site (a wetland site of international importance).
East Head is approached from the far western end of the West Wittering beach car park and has been managed by The National Trust since 1966. Its coast is managed by both hard and soft engineering strategies.
Soft engineering
Hard engineering
Not everyone is in favour of these methods –
For Against
• Local people with homes in danger.
• Local tourist businesses with caravans and hotels at risk (but if the structures are ugly will that not scare tourists away?!)
• Local taxpayers who don’t live next to the coast (why should they pay?!)
• Environmentalists – fear that habitats and natural beauty will be affected
• People living downdrift of the defences could be starved of sediment (like the people at Barton when the 1938 groyne was built at Hengistbury Head) and lose their beach.
The Coastal Zone
Coastal habitats-East Head Spit
Also use for Hard and Soft engineering
East Head
• Sea defences have interrupted the natural coastal processes in the area for the last 200 years.
• In the 1960s and 1970s the narrow beach at the Hinge was breached during high tides/ severe storms and this was again threatened in 2004.
• This was deemed to be unacceptable as this would change currents at the entrance of Chichester Harbour. The cost of which would be hard to imagine as the sailing industry in the area is worth millions of pounds.
• In 2005 a rock berm was placed at the Hinge. Gabion cages and wooden groynes have also been employed. There are even the remains of a wave revetment at ‘The Hinge’ of the spit. (HARD MANAGEMENT)
• In 2005 and again in 2009, huge amounts of sand (15,000 cubic metres) was taken from the northern end of the spit and placed at the narrow point of the spit. (SOFT MANAGEMENT)
• Marram grass was planted to stabilise the feature. Psychological barriers were also constructed to encourage people not to go on the newly created sand dunes. (SOFT MANAGEMENT)
• Similar barriers were also used to rope off the breeding area for the Ringed Plovers and also the Silver Spiny Digger Wasp. (SOFT MANAGEMENT)
ALL THESE THINGS ARE DESIGNED TO MAKE USE OF EAST HEAD SUSTAINABLE
Conflict at East Head
• The sand dunes are fragile and don’t react well to humans!
• Too many tourists can bring litter and fire hazards.
• East Head is a habitat for many rare species – i.e. The Digger Wasps and Ringed Plover.
• The beach can become very crowded.
• Visitors need somewhere to park, plus other facilities like toilets and paths.
• Coastal erosion.
Solutions at East Head
• Marram grass planted.
• Dunes fenced off to prevent trampling.
• Shop and café placed far away from the spit and bins provided.
• Boardwalks used on the spit to prevent trampling.
• Information signs educate people about the environmen.t
• Area roped off for the Digger Wasps.
• Area roped off for the Ringed Plover.
• Car parking charges helped fund the protection of the beach and spit.
• Groynes.
• Gabions.
• Toilets provided.
• Beach recycling (2005 and 2008).
The Coastal Zone
Managed retreat – Medmerry Scheme, West Sussex.
East Head is just to the NW of Medmerry.
Medmerry Managed Retreat near Selsey
• Low land near Selsey under constant threat. Low
• value farmland – why bother protecting this?
• Decision made to punch a hole in the defences and
• build an earth wall inland. The sea flooded the land
• and a salt marsh has been created. Great for wildlife!
• Increased flood protection for 300 homes, the
• sewage treatment works and the main road into Selsey.
• Finished November 2013.
• 10km of paths created.
