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.
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.
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:
The Phillipines 1966-1986, rice production increased from 3.7 million tonnes to 7.7 million tonnes
'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
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 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.
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.
Pools are are areas of deeper calmer water with greater erosion and where the river flows faster due to reduced friction.
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
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:
Young families are leaving for the mainland/abroad
Replaced by people retiring there or young people wanting jobs with the local authority or health board
Those Young professionals are not raising families in the area
Houses only have one or two people in
Young People leave for further education
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.
Variety/Plentiful jobs oppurtunities, for example in the tourist industry
Elderly people retiring to more scenic areas
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:
Many of the people left behind are elderly with less mobility, limited means or disenfranchised
Houses may be brought as second homes creating a ghost town effect
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:
91% of families have 2 or more cars, increasing air pollution, congestion and likelihood of traffic accidents
Traditional rural identity may be lost due to influx of foreigners
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
Lulworth Cove is one of the world's best examples of a cove:
Formation:
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.
The river erodes a valley on the frozen rocks
During the inter glacial period the climate warms and sea levels rise. The sea uses the river valley to enter the coast line.
The sea erodes the rocks, particularly the less resistant ones like Wealden Beds and Green Sands
The erosion continues and the cove grows
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)
