Sunday 21 April 2013

Formation of Wave Cut Platforms


High and steep waves crash into the foot of the cliff, focusing their erosive capabilities into a small area.

A wave cut notch is created by undercutting the cliff:
Continual undercutting causes increased stress and tension in the cliff which eventually collapses.

Rock debris collects at the foot of the cliff and forms a terrace which is eventually moved into deeper water by backswash or along the beach by longshore drift.

The cliffs continue to retreat leaving behind a gently sloping (less than 5 degrees) wave cut platform.

This means that the waves break further out to sea and have to travel across more platform before reaching the cliff line.

This leads to a greater dissipation of wave energy which reduces the rate of erosion of the headland which slows the growth of the wave cut platform.

Saturday 20 April 2013

Managing Coastal Environments: Shoreline Management Plans

have been developed by local councils and the environment agency, adopting a more holistic approach.

Coastal defence authorities can't carry out works without the aid of a shoreline management plan.

Tend to include:

  1. Hold the Line - maintain/upgrade the level of protection provided by the existing coastal defences
  2. Advance the line - Build new defences seaward of the existing defence line
  3. Managed Realignment - allow retreat of the shoreline inland with management to control or limit that movement
  4. No active Intervention - a decision not to invest in providing or maintaining defences
Sustainable Future?
  • Sea levels are predicted to continue to rise approx 6m a year because of global warming
  • Areas of the UK continue to sink because of isostatic uplift, changing at the rate of 2mm a year
  • The use of public money to defend the undefendable is unsustainable
  • A 'do nothing' approach is often the only affordable way in the long term


Sediment Cells

The movement of sand and shingle in the nearshore zone by longshore drift has been found to occur in discrete, functionally separate sediment cells.

There are 11 such cells around England and Wales with smaller sub cells within them eg from The Wash to The Thames.

The main cells are defined as a length of coast and its associated nearshore area within which the movement of coarser sediment is largely self contained.

Interruptions to sediment within one cell should not affect beaches in adjacent cells.

Malthusian population theory

Name: Thomas Malthus
Date: 1798

Main Arguments:

  • Population increases faster than food supply and supporting resources
  • Increasing population could lead to war, famine and disease
  • PREVENTION: Celibacy, delaying marriage and having less children
  • War, famine and disease are good things as they increase mortality
Limitations/Criticisms:
  • Didn't foresee the development of new technology like GM crops
  • Was wrong in assuming that overpopulation was the reason for famine, there are many factors, like war
  • Didn't consider that people would eventually control their birth rates
Case Study:
In 1960 Mauritius had finite island and the fastest growing population in the world.
Most of the land was used to grow sugar, but it was a cash crop that went to MEDCs.

How it was solved:

Family planning meant that fertility rates were halved from 6 children a woman to 3.

Promotion of contraception meant that in 2001 the population was 1.1 million where it would have otherwise been 3 million.

Ester Boserup Population Theory

Name: Ester Boserup
Date: 1965

Main Arguments:

  • Increases in population stimulates the development of technology for things like food production
  • Incentive to modify technology to produce more food
  • "Necessity is the mother of all invention"
  • eg GM crops
Limitations/Criticisms:
  • Things like GM crops are more susceptible to disease
  • GM seeds are more susceptible to drought
  • There was a 27% increase in cancer rates after they were introduced in the Phillipines
Real life examples:
  1. The Phillipines 1966-1986, rice production increased from 3.7 million tonnes to 7.7 million tonnes
  2. 'Green Revolution' the widespread introduction of high yielding seeds, water control and mechanisation, use of fertilizers and pesticides to allow more people to be fed

Friday 19 April 2013

Case Study: US Health system and French Health System

USA: Free market health care provision 
  • Based on the principles of a free market economy
  • Extremely privatised
  • Most care providers are privately run organisations
  • There are a few federal, state, county and city run facilities
  • 65% of hospitals are privately run not-for profit organisations
  • Per Capita expenditure on health was US$6714 in 2006
  • One of the most expensive models in the world
  • Usually provided through health insurance with 64% of the population having some sort of medical insurance plan
  • Insurance is often paid for by employers as part of a salary package - the health insurance alone is around US$10,000 per year to an employee and their family
  • Health insurance companies operate to make a profit
  • Recently introduced some governmental support - all Americans over the age of 65 have access to Medicare
  • Medicaid provides basic state provided health care for the poorest people but not comprehensive cover - 14 million people still have no acces to healthcare
  • Around 15% of the US population (45 million) does not have any health insurance
France
  • Mainly funded by the government 
  • Administrated through a number of social insurance schemes
  • In 2004 80% of the population were covered by the main State regulated insurer
  • Individuals must pay a compulsory health insurance of 0.75% of their earnings which is deducted from their salary
  • Their employer then makes a 12.08% contribution
  • About 85% of the population also pay a voluntary top-up premium of 2.5% of their income to make sure all their health costs are fully reimbursed
  • Recently introduced a system of health coverage CMU so that those earning less than 6600 euros don't have to make any health insurance payments
  • Provided by general physicians
  • No restrictions on where doctors can set up their practises
  • Individuals have the choice of using more than one general physician
  • You can demand access to hospitals and specialist services without a referral from a general physician

Healthcare Systems

Emergent:

  • Healthcare viewed as an item of personal consumption
  • Physician operates as a solo entrepreneur
  • Professional associations are powerful
  • Private ownership of facilities
  • Direct payment of physicians
  • State's role in healthcare is minimal
  • Development of local health workers 
Eg, in India healthcare is highly diversified with both western and traditional practises operating.

Socialised:
  • Healthcare is a state-provided service
  • Physicians are state employed 
  • Professional associations are weak or non existenet
  • Facilities are wholly publicly owned
  • Payments for services are entirely indirect
  • State's role in healthcare is total
Cuba's health service is very effective, with the WHO ranking it just below the USA's despite the fact it spends 10x less. 

1 in 6 doctors in South Africa are Cuban partly because there are 21 medical schools providing free training.

Pluralistic:
  • Healthcare viewed as a consumer product 
  • Physician operates as a solo entrepreneur
  • Professional associations are powerful
  • Private and public ownership of facilities
  • State's role in healthcare is minimal and indirect
In the USA the health system is provided by thousands of independent doctor, clinics and pharmacies however the federal government recently introduced Medicaid and Medicare.

Insurance/social security:
  • Healthcare is an insured and guaranteed consumer product 
  • Physicians operate as social entrepreneurs and as members of strong professional associations
  • Private and public ownership of facilities
  • Payment for services mostly indirect
  • State's role in healthcare is evident but indirect
WHO judged the French healthcare system to be the most effective in the world, but it also very expensive accounting for 10% of France's GDP.

National Health Service:
  • Healthcare is a state supported service
  • Physicians operate as solo entrepreneurs and as members  
  • Facilities are mainly publicly owned 
  • State's role in healthcare is central and direct
The only countries with national health care are the UK and Canada. Canada's aim is to provide its citizens with equal access to healthcare regardless of their ability to pay in a scheme known as Medicare.


Thursday 18 April 2013

Helicoidal Flow

Helicoidal Flow is the cork-screw like flow of water in a meander.

It is a contributing factor to the formation of sli off slpoes and river cliffs in a meandering section of river. The helicoidal motion of the flow aids the processes of hydraulic action and corrasion on the outside of the meander, and sweeps sediment across the floor of the meander towards the its inside.

The Genesis of a Meander

Pools are are areas of deeper calmer water with greater erosion and where the river flows faster due to reduced friction.
Meandering River Wharfe

Riffles are wide shallow areas of the river where water 'ripples' over pebbles beds with protruding rocks.

As these pools and riffles enlarge, the river will be propelled by centripedal force to twist round the riffles thus starting the side to side flow of the river. Erosion occurs on the outside of the bend, while deposition occurs on the inside.

All rivers take the path of least resistance to maintain theire maximum velocity (thalweg).

Outside of the bend:

  • Fastest flow
  • Lateral erosion
  • Hydraulic action
  • Undercutting of the alluvial materials of the river's floodplain
  • Abrasion
  • Deeper
  • River cliff

Inside of the bend:

  • Deposition
  • Shallow
  • Slowest flow
  • Slip off slope/point bar
  • Low energy

Monday 15 April 2013

The Demographic Transition Model


Stage 1: High Fluctuating, eg Zimbabwe

Reasons for High Birth Rate:

  1. High infant mortality rate
  2. In some cultures children are a sign of fertility
  3. Limited birth control/family planning
  4. Future source of income

Reasons for High Death Rate:

  1. Poor levels of hygiene facilitates the spread of disease
  2. Not much food surplus, famine
  3. Inadequate health facilities

Stage 2: Early Expanding eg Uganda

Reasons for falling death rate:

  1. Industrialisation generates wealth leading to an improvement in public health
  2. Increase in personal wealth means better nutrition
  3. Improvement in public health facilities and widening access to healthcare, often leading to a decrease in child mortality rates

Stage 3: Late Expanding eg China

Reasons for a falling birth rate:

  1. Increasing personal wealth leads to a change in social trends and fashions followed by a rise in materialism
  2. Better access to family planning
  3. Compulsory schooling makes children more expensive
  4. Improved access to health and sanitation facilities leads to a lower infant mortality rate
  5. Greater access to education for women and later marriages leads to a preference for smaller families


Stage 4: Low Fluctuating eg Japan

Reasons for fluctuations in Birth/Death rate:

  1. Increase in lifestyle diseases from low excersize and fatty foods
  2. Groth of and acceptance of childlessness
  3. Growth of individualism linked to women working
  4. Greater financial independence of women
  5. Concern for the impact an increased population has on the world's resources
  6. Breakout of relatively new epidemics/pandemics eg AIDs

Stage 5: Decline eg Germany

Wednesday 10 April 2013

Rock Types at Lulworth

Rock Type
Sediment
Picture
Chalk - limestone
Marine Organisms
 
Greensand - sandstone
Sand grains
 
Wealden Beds – Sandstone, clays
Sand grains, clays and organic matter
 
Purbeck Beds – limestone, clays, shales
Shells, clay, silt
 
Portland Limestone
shells
 

Rock Types

Igneous Rocks have crystallised and solidified from molten lava

Sedimentary Rocks are acculmulated debris of older rocks and often contain organic remains

Metamorphic Rocks are either igneous or sedimentary rocks that have been altered by heat or pressure

Population Change in the UK

IMMIGRATION and it's effects...

Because Emigration is falling while Immigration is increasing the UK's net migration is rising.

Positive Attitude
Negative Attitude
-Immigrants create jobs eg Polish food shops
-Is earning capacity the only way we measure an individual’s contribution to society?
-Less likely to claim state benefits
-Work harder because they have to
We are all immigrants originally
-Why should it be easier to marry someone from Poland than from Pakistan – Racist policy?
-Often take low skilled and low paid jobs that established population might not want eg cleaner
-Use medical resources
-Too many immigrants for jobs
-Councils have to find more housing etc

Some proposed plans for immigration:

  1. Limiting skilled workers's stay to 5 yrs would damage the UK economically - 50,000 fewer skilled migrants cost every person £44 extra over 5 years
  2. Fewer visas to students who are the largest group of non-EU migrants, but £8.5 billion is generated in fees
  3. Only Husbands or Wives earning £18,200 - a policy for the wealthy
Social Benefits of Migrants: 
  • Increases understanding of other cultures
  • Influx of new or revitalized providers of local services
Economic Benefits:
  • Growth in ethnic retailing eg Curry mile in Manchester
  • Tend to take the less desirable jobs
  • Fill the skills gap that exists in many host countries with qualified migrants
  • Costs of retirement transferred back to the source country
  • Host country gains skilled labour at reduced cost
Social Costs:
  • Entrenchment of attitudes which may lead to fundamentalism
  • Groups of segregated ethnic groups are created and dominate local schools
  • Male Dominance reasserted especially in countries where women have low status like the Persian Gulf States
  • Racist attitudes which may lead to civil unrest and extremism
  • aspects of cultural identity is lost especially amongst second generation migrants
  • call for controls on immigration
Economic Costs:
  • Cost of educating migrants children
  • Much of the money goes back to the country of origin including pension payments
  • Increased numbers of people puts pressure on resources like health services and education
  • Some industries like construction over depend on migrant labour

The Impact Of Migration on Population Structure: Barra

 

BARRA is an island in the Outer Hebrides that has long experienced depopulation.

Affect on population pyramid:

  • A relatively high proportion of elderly people, who may retire to Barra, or due to a lack of mobility can't leave
  • Compared to Scotland's national average there are relatively few people of working age - perhaps due to lack of job oppurtunities
  • The birth rate is in decline
Some Facts:

-The Ministry of ddefence has axed 125 jobs in the Hebrides

-The Hebrides population has declined from 30, 711 people in 1981 to 29,600 in 2001.

-On the island on Scalpay there are no children left under the age of 7

-As of 2001 26 islands had no inhabitants

Reasons:
  1. Young families are leaving for the mainland/abroad
  2. Replaced by people retiring there or young people wanting jobs with the local authority or health board
  3. Those Young professionals are not raising families in the area
  4. Houses only have one or two people in
  5. Young People leave for further education
  6. Not viable making a living in some of the traditional ways any more eg working croft
However, some places have tourist industries, including Barra, which help bring employment and revenue to the area, and the Scottish Executive has a Air Discount Scheme which provides a 40% discount on flights to the islands. Other nearby islands like Fair Isle attract tourists with their bird sanctuaries. 

Barra's Tourism Website: http://isleofbarra.com/

Barra's YouTube Page: http://www.youtube.com/user/Barrafilm?feature=watch



Tuesday 9 April 2013

Population Change in Rural Areas

Some areas are declining in population because:

  1. Lack of services/things to do for young people
  2. May lack accessibility

Some areas are expanding in population because:

  1. Variety/Plentiful jobs oppurtunities, for example in the tourist industry
  2. Elderly people retiring to more scenic areas
  3. Less expensive to set up businesses or buy houses despite proximity to larger urban areas

Effect on Population pyramids:
Remote Rural Area in Decline eg Worth Matravers = 240 people

  • Strong Retirement element or people who have lived there for many years
  • Wasted shape as young people move away to look for work or cheaper housing
  • Regressive base as few children are born
Consequences of decline:

  1. Many of the people left behind are elderly with less mobility, limited means or disenfranchised
  2. Houses may be brought as second homes creating a ghost town effect
  3. People left behind may be unable to leave as they lack the skills or mobility


Accessible Rural Area Expanding eg Corfe Castle = 980 people

  • Relatively fewer older people
  • New arrivals who commute to work (91% of people have car access or work from home)
  • Expanding population as there is a baby boom because of the young families who move into the area
Consequences of expansion:

  1. 91% of families have 2 or more cars, increasing air pollution, congestion and likelihood of traffic accidents
  2. Traditional rural identity may be lost due to influx of foreigners 
  3. May be conflict between established locals and new families moving in
Changes in Services:
Changes for the better J
Changes for the worse L
-Opening more nurseries has created increased the number of children in schools. Grants and shared headships can be used to support schools

-Many village stores have been replaced by supermarkets which have cheaper prices, longer opening hours and often run a bus service from local villages

-Grants can be obtained for the refurbishment of village halls

-Cooperation between post offices and banks to provide an combined service

-Increase in number of mobile libraries

-New types of village shops like farm shops or garage shops

-Grants available for community bus or taxi services like the postal bus service which combines transport with letter delivery

-Mini-health centres have been set up in larger villages and grants are available to support rural GPs and pharmacies
-Local services have been cut

-Aging population means there are fewer school children, with schools competing for them or closing, and wealthy parents putting children into public schools

-Post offices being downgraded to part time or hole in the wall, with pension services often being moved to banks

-Some GPs have closed and there is a decline in dentist surgeries

-Funds have been cut for youth clubs and activities for the elderly

-Closure of uneconomic bus routes and reduction in cross-county services along with an increase in car ownership



   

Purbeck
UK
0-14
18%
20%
15-64
60%
64%
65+
22%
16%

Monday 8 April 2013

Coastal Management: Sea Wall



  • Hard Engineering
  • Deflect wave energy - storm waves are deflected

Pros
Cons
Highly Effective
Provides walkway for tourists
Aesthetically unattractive
Very Expensive
Where cliffs are prone to slumping landslides can cover the wall
Stronger backwash which can worsen longshore drift

Cove Formation

Lulworth Cove is one of the world's best examples of a cove:


Formation:

  1. In the glacial period 10,000 years ago the ground was frozen, including the underlying chalk (which is normally permeable) so a river could flow over the concordant coastline.
  2. The river erodes a valley on the frozen rocks
  3. During the inter glacial period the climate warms and sea levels rise. The sea uses the river valley to enter the coast line.
  4. The sea erodes the rocks, particularly the less resistant ones like Wealden Beds and Green Sands
  5. The erosion continues and the cove grows
  6. Finally there is a fully mature cove, wide in the middle (because of the less resistant rock there), narrow at the neck (the purbeck and portland limestone is more resistant to erosion) and elliptical (the chalk is also quite resistant to erosion)
Rock Stratas:

Beach Management: Groynes


  • Hard Engineering
  • Prevent longshore drift, holdng the beach in place
  • Beach provides a buffer zone which reduces cliff erosion
Case Study: Swanage Bay Beach
  • In Swanage, the groynes are only built up to the end of the town so it is protected while allowing  natural processes to continue beyond the town
  • New timber groynes were built to replace old ones in 2005-6
  • The old groynes had been in place for 75 years
Pros
Cons
  1. Keeps beach in place for tourists
  2. Doesn’t look as unnatural as some other hard management schemes
  3. Relatively easy to maintain
  4. Cheaper than a sea wall

  1. Inhibits people’s movement on the beach, making it less usable for elderly people and dogwalkers especially as they make the beach uneven
  2. Needs maintenance
  3. May have knock on effects where the groynes end, exposing area beyond the groynes to greater erosion