Wednesday, 16 April 2008
Glaciation
Definitions:
Abrasion - A glacial erosion process. When blocks of rock debris are trapped on the underside of a glacier and then, as the glacier moves, this has a sand paper effectwearing away the base and sides of the valley.
Arete - a knife edge ridge that separates two corries e.g. Striding Edge
Corrie - an arm chair shaped depression formed on the side of a mountain e.g. Red Tarn
Frost shattering - a weathering process. Water gets into cracks in the rock. When the tempreature drops beloow zero, the water freezes and expands exerting pressure on the sides of the crack. Eventually the crack is widened and the rock disintegrates.
Glacial trough - U - shaped valley which has been widened and deepened by a valley glacier e.g. Patterdale
Glacier - a mass of moving ice
Plucking - A glacial erosion process. Water enters cracks in the rock and freezes so that it is attached to both the rock and the glacier. When the glacier moves, the block of rock is pulled out of the ground.
Ribbon Lake - a long thin, deep lake on the floor of a glacial trough e.g. Thirlmere
mnemonics
Rural to urban migration
Think PUSHED for Push factors
P - pressure on land so many have to leave
U - unemployment in the countryside
S - sanitation - poor or non-existent in rural areas. Often no running water or clinics
H - hardship - often a harsh climate
E - education - little if any
D - disasters, drought, famine, civil war etc
PULL Factors
B - better paid jobs or perceived better job opportunities, factory jobs which are not dependent on the weather
E - education provision is better
P - perception that city life is better
H - More provision of health care
Characteristics of out of town shopping centres - use your case study of Merry Hill and try to suggest reasons for its location under the following points : CAR SPACES
C - cheap land
A - accessibility
R - redeveloped loand
S - sphere of influence
P - parking
A - all weather shopping
C - choice of shops
E - expansion
S - secure
Sunday, 13 April 2008
Road transport
Traffic problems
- air and noise pollution
- health problems
- greater demands on car parking
- heavy congestion
- commuter traffic - twice daily build up
- danger to pedestrians
- vehicle vibrations can cause damage to old buildings
- cost of road maintenance
- old buildings cleared to make way for new roads
Solutions
1. reduce the amount of traffic entering the urban area: - traffic free zones, park and ride schemes (Cambridge, Stratford upon Avon), inner and outer ring roads (Birmingham), bypass, motorways, M6 Toll, congestion charges (London)
2. encouraging people to use public transport: - reliable and frequent bus service, fare reductions (e.g. season tickets), bus only lanes so public transport is faster, installing new rapid - transport systems (Manchester Metro)
3. Reducing air pollution from vehicle exhausts by:- enforcing law on vehicle emissions
using traffic control methods: traffic lights
Case Study - Birmingham
In Birmingham, there have been major traffic problems in the past, particularly around the main routes into the city centre. In order to tackle this, Birmingham City Council have taken a number of measures. In the North they have turned the A38 into a tidal flow road, which is now known as the Aston Express Way. This allows them to change the number of lanes entering and leaving the city to cope with the rush hour. In addition there is also an urban motorway with up to 8 lanes for traffic to cope with the volume. In the East the Stratford Road is now a red route, which means that there is no stopping allowed along this stretch of road and thus maintains the flow of traffic. The main heart of the CBD around New Street, is pedestrianised with bus lanes all around the edge of the CBD. This allows commuters to reach the centre easily and quickly whilst keeping them safe. To the West of Birmingham a rapid transit system (trams) has been set up running from the Black Country into Snow Hill Station, in the business area of the CBD. This is a park and ride scheme aimed at commuters and runs every 10 minutes during the week. There has been major investment in the public transport network with Travel West Midlands offering integrated timetables linking bus routes with trains. All prices on public transport are kept below £1.00 per journey to encourage people to use it. The road network is well organised with both an outer and inner ring road keeping traffic away from the city centre. In 2003 the M6 Toll Road was opened which takes traffic away from the motorways around the edge of Birmingham in order to reduce pressure and congestion on these roads.
With thanks to Miss West and Rachel
Counter-urbanisation
The movement of people out of urban areas (e.g. inner city areas) into a more rural environment (suburbs)
Why do people want to move away from the more urban areas: (PUSH FACTORS)
- higher density housing
- little space
- less room
- poor quality housing
- higher crime rates
- more congestion
- higher levels of air and noise pollution
- both shopping and industry are tending to move towards outskirts
Why are people attracted to the more rural areas? (PULL FACTORS)
- more spacious
- better quality of housing with more modern amentities, double glazing, detached properties, front and back gardens, garages, utility rooms
- bigger houses and gardens
- safer for children
- less congested
- improved transport makes commuting possible
- more attractive environment close at hand
- new residential estates
- closer to modern industrial estates set up in rural fringe
- less air and noise pollution
Effects of out-migration on the more urban areas:
- less people
- derelict land as industry moves out
- elderly and unemployed people left behind
- loss of 'community spirit
- older housing becomes more run down, empty houses are boarded up
- shops close due to less custom
- less government investment
Effects of in-migration on more rural areas
- pressure for more new housing development
- rise in house prices (young cannot afford homes and move away)
- schools become more overcrowded
- more pressure on local services - doctors
- locals swamped by newcomers - friction
- becomes busier, area looses its charm
Outer Suburbs - Monkspath, Hillfield, Solihull
Disadvantages
inner city
Road pattern
1. Cheap to acquire
Disadvantages
CBD
Characteristics
road and rail routes converge
high land values leading to tall buildings
competition for land
shops, high order, large departmental stores and specialist shops
banks and offices
often central area is pedestrianised
congested with traffic and people
Urban Definitions:
Commuter – a person who lives in one settlement and travels daily to work in another settlement.
Commuter village – a village where a large number of the residents travel to work each day in another settlement and then return each evening
Comprehensive redevelopment - the rebuilding of housing and industry together with roads and environmental improvements
Gentrification – Professional people return to live close to the city centre by buying up older substandard housing which is then substantially improved.
Green belt – the area of land around a large urban area where the development of housing and industry is restricted and the countryside is protected for farming and recreation
Housing renovation – The improvement of homes by adding inside bathrooms, toilets, central heating etc.
Inner city – The area occupied by 19th century factories and terraced housing
Migration – the movement of people, either voluntary or forced, between or within countries
Out of town shopping centre – A retail park built in the countryside on the edge of a town –e.g. Merry Hill
Retail park – A group of large one storey shops with car parks built close to a major road,
Rural – urban fringe – area between the built up area and the countryside where there is often competition for land use e.g. golf courses, business parks, residential homes
Shopping centre – A group of shops
Slum clearance – the removal of old and decayed housing
Suburb – the outer, usually, residential area of a town or city
Suburbanisation – The growth of housing and population in the outer areas of a town
Twilight zone – The area of decay between the CBD and the inner city
Urbanisation – When the percentage of the population living in towns within a country increases
Urban morphology – the pattern of land use in a town
Energy: location and requirements
Requirements:
Large flat site in areas of low population density and where land is of little agricultural value - cheap
Access to gas fields – e.g. North Sea
Close to river for cooling water and als water needed to produce steam for generation
COAL - located on coalfields, close to collieries and existing open cast coal mines e.g. Selby, Case Study: Eggborough Humberside
Requirements:
Large flat site
Built on or near large supplies of coal (mine) because it is bulky and very expensive to transport
Often linked to pits by special railways that only carry coal. By locating close to mine and building rail links, transport costs are reduced
Located along major rivers because large amounts of water are needed to produce steam to drive turbines and need large amounts of cooling water
Many are near to urban areas many of the large conurbations developed on the coal fields during the time of the industrial revolution
NUCLEAR - scattered locations around the country. Case Study Heysham, Lancs
Requirements
Located away from large populated areas in case of accidents and also as there is less opposition to building plant
Large, flat site
Low value land
Stable bedrock
Located on the coast as vast amounts of water are needed for cooling purposes
Good transport links for both raw materials and waste products
WIND - farms - majority are located in west of country, in upland areas. No wind farms in National Parks. Case Study Lambrigg wind farm, Cumbria
because ....
Areas with high and regular wind speeds so often found in exposed coastal locations or in remote upland areas
The wind speeds are higher in the west of the country
In Britain there are more days when winds blow from the west than from any other direction so there are more days when the wind turbines can be operated.
At higher altitudes, wind speeds are faster and there are fewer obstacles to block the wind.
Wind farms are not built where they would detract from the natural beauty of a National Park
HEP - Found mainly in the north and west of the UK in upland areas. Case Study: Cruachan W. Scotland
Requirements:
Large and regular rainfall (> 1500mm pa) and low rates of evaporation in order to provide a constant supply of water.
Upland areas where narrow valleys which are ideal for dam construction and water storage
Strong and impermeable bed rock so water does not drain away through the rocks
Cheap land, sparsely populated
Steep upland gradients or former waterfall to give the necessary high head of water to turn the turbines
Electricity generation.... definitions
Fossil Fuel - Non renewable forms of energy formed through past organisms, coal, oil, natural gas. When burnt, these release carbon
Hydro electric power - The use of falling water to turn a turbine to generate electricity
Non-renewable energy - A fuel source which can only be used once before it is exhausted because it takes millions of years to form
Renewable energy - A source of fuel which can be used over and over again, e.g. wind, solar
Thermal power station - Power stations which use heat to make steam which turns the turbines to generate electricity. The heat can be made from the burning of coal, oil or gas or alternatively from nuclear reactions or use of geothermal activity.
Energy - types, advantages and disadvantages
Gas - Advantages
More efficient to burn and easier to transport and distribute (by pipeline and tanker) than coal. Cleaner, cheaper and less harmful to the environment than coal.
Safer than nuclear energy.
Gas - Disadvantages
It is a fossil fuels so adds to global warming and the creation of acid rain.
It is a non-renewable resource so supplies will eventually run out.
Coal - Advantages
Reserves are likely to last for over 300 years.
Improved technology has increased the output per worker, allowed deeper mining with fewer workers and made conversion to electricity more efficient.
Coal also used for heating and making coke.
Coal - Disadvantages
The most easily accessible deposits have been used up and production costs have increased.
There is increasing competition from other types of energy.
It is a fossil fuel and so contributes to global warming and the creation of acid rain.
Deep mining can be dangerous, while opencast mining temporarily harms the environment.
Coal is heavy and bulky to transport.
Nuclear - Advantages
Only very limited amounts of raw materials are needed, e.g. 50 tonnes of uranium per year compared with 540 tonnes of coal per hour needed for coal-fired stations.
Safeguards make the risks of accidents minimal.
Reserves of uranium will last much longer than those of coal and gas.
Waste is limited and can be stored underground.
Nuclear power is believed to contribute less than coal and oil to the greenhouse effect and acid rain.
Nuclear - Disadvantages
It is not clear how safe nuclear power is.
Conservationists argue that one accident may kill many, and ruin an area of ground for hundreds of years.
There are potential health risks. The high incidence of leukaemia around Sellafield and Dounreay has been linked to proximity to nuclear power stations.
Nuclear waste can remain radioactive for many years.
The cost of decommissioning old power stations is extremely high.
HEP - Advantages
Hydro-electricity is renewable and is often produced in highland areas where the population is sparse.
It is a relatively cheap form of power and creates little pollution.
Dams built to store water for HEP production can also reduce risks of flooding and water shortages.
HEP - Disadvantages
Dams are very expensive to build.
Large areas of farmland and wildlife habitats may have to be flooded forcing people and animals to move.
Unsightly pylons can cause visual pollution and there is the
Possibility of the dam collapsing.
Silt, previously spread out over farmland, will be deposited in the lake.
More recently, it has been shown that if an area is flooded, the decaying vegetation can release methane and carbon dioxide - two greenhouse gases.
Solar- Advantages
Safe
Pollution free
Efficient
Limitless in supply
Solar - Disadvantages
Technology to build cheap efficient solar power stations has not yet been developed
In countries such as the UK, capability to produce large amounts of solar energy is greatly reduced in the winter, when daylight is shorter and the sun is at a low angle in the sky
Need a large number of panels for small amount of energy
Wind Advantages
Capable of being developed commercially in the UK
Safe, clean (no radioactive or chemical emissions) and does not contribute to global warming or acid rain
Has a minimal effect on local ecosystems
Winds are stronger in winter when demand for electricity rises
After the initial construction electricity production is relatively cheap
Wind farms provide a source of income for farmers and may attract industry in isolated rural areas
Future wind farms are likely to be built offshore
Wind - Disadvantages
Expensive to build and maintain. Around 7000 turbines needed to produce the same amount of electricity as 1 nuclear power station. As many as 100 000 wind farms may be needed if UK is to generate 20% of its total energy from wind
Wind does not blow all the time
Wind farms spoil scenic countryside and areas
Wind farms are noisy and can interrupt radio and TV signals for people living nearby. Affect property values
Still an expensive and not very efficient way of producing electricity
Friday, 11 April 2008
Farming definitions
Growing of crops
Agribusiness
Large scale, capital intensive farms that specialise in only a few crops and use scientific advisers and techniques together with business principles to produce the maximum yields and quality. Often tied to supermarkets or processors to buy the crops
Biodiversity
The number and variety of plant and animal species found in an ecosystem
Capital intensive
Large capital investment in machinery, chemicals etc to maximise outputs
Common Agricultural Policy
The E.U policy on farming. By guaranteeing prices on many foodstuffs, CAP ensures that farmers earn enough money to be able to make a decent living and invest in their farms.
Crop rotation
The system, of growing a sequence of crops in strict rotation in the same field in order to maintain soil fertility
Diversification
Farmers are encouraged to find new ways of using their land
Economies of scale
Cost savings made by production on a large scale
Eutrophication
Chemicals (particularly nitrogen and phosphorus) from fertilisers seep into streams etc. Here it causes rapid growth of algae which blocks sunlight. Oxygen is used up and stream life begins to die.
Fallow
Land left unseeded after being ploughed and harrowed to regain fertility
fertilisers
Chemicals which add nutrients to the soil to replace those that the crops take out
Food mountains and lakes
Mountains – grain, butter, beef
Grant
Money which is given to a farmer to cover cost of farm improvement
Herbicides
Chemicals which kill weeds which might compete with the crops for nutrients and sunlight
Insecticides
Chemicals which kill insects which might eat crops or damage them
Intensive farming
There are large inputs to each hectare in order to produce large outputs of crops
Labour intensive
A system of farming which requires a heavy amount of hand labour
Ley
An area of land temporarily under grass
Mixed
Farming involving both animals and crops
Monoculture
Production of a single crop
Pastoral
Farming which rears only animals
Pesticides
Chemicals which kill pests such as fungus which can damage crops during growth.
Quota
A set amount of food which a farmer is allowed to produce
Set aside
A policy whereby farmers leave some land unused and receive a payment in compensation
Subsidy
Money given to farmers when the market price for their produce is low. This ensures that farmers do not make a loss.
Surplus
Overproduction of certain crops which need to be stored
Lakes – overproduction of liquid farming products: olive oil, wine, milk
Monday, 7 April 2008
Definitions
Abrasion (Corrasion) : Wearing away of the bed and banks due to the action of water and the load. Sand paper effect.
Attrition: The wearing down of rocks and pebbles into smooth rounded particles due to transport by the river.
Hydraulic action: Force of the running water erodes the banks of the river.
Solution (corrosion): The water dissolves particles in the rocks
River Transport Definitions:
Saltation: Sand sized particles are bounced along the river bed
Solution: The water dissolves material
Suspension Small clay sized particles are carried along in the flow of water
Traction: Large boulders are rolled along the bed of the river
Hydrological cycle terms:
Condensation: Process whereby water vapour changes to water liquid
Evaporation: The process whereby water liquid is turned through heat into water vapour
Groundwater: Water underground which has collected from the downward movement of water through the soil and rocks
Impermeble rocks: A rock which does not allow water to pass through
Infiltration: The downwards movement of water through the soil laters
Interception: Trees and vegetation blovck the path of rainfall to the ground
Percolation: Downwards movement of water through the rock
Permeable rock: A rock which does allow water to pass through due to spaces between grains
Precipitation: The deposition of moisture on the Earth's surface - rain, sleet, snow and hail
Stemflow: Water flows down through stems and branches
Transpiration: The process whereby vegetation fives off moisture to the atmosphere
General River basin terms:
Tuesday, 1 April 2008
Rivers
Syllabus Content:
River Processes - erosion, transport and deposition
The course of a river - you should know the main changes in both river channel and valley as it passes from source to mouth - cross profile and long profile
River Features:- describe and explain the characteristics / formation of each - state the processes involved.
Upper Course of the River - v-shaped valleys and waterfalls
Middle Course of the River - meanders and ox-bow lakes
Lower Course of the River - floodplains, levees, deltas
Erosion key words:
hydraulic action
abrasion / corrasion
Solution / corrosion
attrition
Transportation key words:
Traction
Saltation
Suspension
Solution
2004 Question 4 With the aid of a diagram(s) explain the formation of a waterfall (7)
2001 Q1d With the help of an annotated diagram, explain how a waterfall is formed (5)
Level 3 answer
Waterfalls are formed where the river meets a band of softer, less resistant rock after flowing over a relatively hard, resistant rock. Initially a series of rapids may form
The softer rock is worn away more quickly by the processes of hydraulic action (the sheer force of the water eroding the soft rock) and abrasion (the swirling action of the river and its load which also erode the softer rock). The harder band of rock is undercut. In time the overlying harder rock (overhang) will become unsupported and will collapse.
At the foot of the waterfall is a deep plunge pool formed through abrasion. The water and rock debris from the overhang will help to deepen the plunge pool. The back wall is further eroded through the process of hydraulic action.
The whole process is repeated many times and will cause the waterfall to retreat upstream forming a gorge
MEANDERS
Concave bank
Outside
Fastest flow
less friction – more energy
River cliff
Erosion
Deep water
Convex bank
Inside
Slowest flow
More friction – less energy
Deposition
2003 P1 Q7 b.
Explain the formation of an ox bow lake. You may use diagrams to help you. (6 marks)
Ox bow lakes are crescent shaped lakes formed on the floodplains of a river in its mature stage.
In a meander the fastest current is on the outside bank. Here the river bank will erode due to the sheer force of the water hitting the bank (hydraulic action) and from the water carrying pebbles (abrasion) to form a river cliff.
On the inside bank the river flow is slower and deposition occurs to form a slip off slope. Lateral erosion of the outer bank and deposition of the inner bank increase the amplitude (bendiness) of the meander
Over time a meander loop may become so pronounced that only a narrow strip of land is left separating two meander loops.
During times of flood the river will break through this and assume a new straighter and shorter course.
Water in the cut off meander is calmer. Deposition continues and eventually separates the oxbow lake from the main river channel. In time the ox bow lake is eventually filled in by marsh plants and peat and is left as a meander scar