Preview from Notesale.co.uk Page 1 of 76

Transcription

1 Geography Unit 1A The Restless Earth 4 Tectonic plates 4 Landforms at plate boundaries 5 Fold mountains 5 CASE STUDY Fold Mountains: The Alps 6 Volcanoes 7 CASE STUDY Volcanic Eruptions (LEDC & MEDC) 8 Supervolcanoes 10 Earthquakes 11 CASE STUDY Earthquake (LEDC + MEDC) 12 Tsunami 13 CASE STUDY Tsunami: Indian Ocean 13 Unit 1B Water On The Land 14 Erosion, transportation and deposition 14 The river valley 15 River landforms 16 Waterfalls and gorges 16 Meanders 16 Ox-Bow lakes 16 Page 1 of 76 Flood plains and levees 17 River discharge 18 Hydrographs 18 Factors affecting river discharge 18 Flooding 19 CASE STUDY Flooding 20 Hard and soft engineering 22 Managing the UK s water 24 Supply and demand of water 24 Managing the supply and demand of water 24 CASE STUDY UK Reservoir: Rutland 25 Unit 1B Ice On The Land 26 Ice over time 26 Glaciers 27 Glacial processes 28

2 Supervolcanoes Characteristics Much bigger than standard volcanoes and only develop in a few places on destructive plate margins, e.g., Yellowstone National Park They are flat unlike other volcanoes, which are mountains They cover a vast area, much bigger than normal volcanoes Supervolcanoes have a caldera rather than a crater at the top Formation: Magma rises up through cracks in the crust, forming a large magma basin and the pressure of this causes a bulge on the surface several kilometres wide The bulge cracks, creating vents for the lava to escape from which causes earthquakes and giant plumes of ash and rock As the magma basin empties, the bulge is no longer supported so it collapses which spews up even more lava After the eruption, a big caldera (crater) is left behind where the bulge collapsed Page 10 of 76 Consequences of an eruption Thousands of cubic kilometres of rock, ash and lava will be displaced causing huge problems A thick cloud of super-heated gas and ash will flow a high speeds from the volcano, killing, burning and burying everything it touches Everything within tens of miles will be destroyed Ash will shoot kilometres into the air and block out almost all daylight over whole continents which will trigger a mini ice age as less energy from the sun will get to the earth The ash will settle over hundreds of square kilometres burying fields and buildings

3 Tsunami A tsunami is a special type of wave where the entire depth of the sea or ocean is set in motion by an event, which displaces water above it and creates a huge wave They are a secondary effect of an earthquake CASE STUDY Tsunami: Indian Ocean Cause There is a destructive plate margin along the west coast of Indonesia in the Indian Ocean On 26 th December 2004 there was an earthquake measuring 9.1 on the Richter scale The plate that s moving down into the mantle cracked and moved very quickly, which triggered a tsunami with waves up to 30 m high Effects It was one of the most destructive natural disasters that has ever happened, affecting most countries bordering the Indian Ocean The effects of the tsunami were so bad because there was no early warning system Social effects Around 230,000 people killed or missing presumed dead 650,000 people injured Whole towns and villages were destroyed, leaving nearly 2 million people homeless Infrastructure was severely damaged 5-6 million people needed emergency food, water and medical supplies Economic effects Millions of fishermen lost their businesses as their boats were destroyed The tourism industry suffered because people were afraid to go there due to the destruction Farmland was contaminated so farmers were unable to grow crops to sell Environmental effects Salination of agricultural land making it infertile Coral reefs and forests were destroyed by the waves Page 13 of 76 Responses Short-term Hundreds of millions of pounds had been pledged by foreign governments, charities, individuals and businesses to give survivors food, water and medical attention Foreign countries sent ships, planes soldiers and teams of specialists to help rescue people, distribute food and water and begin clearing up Long-term Billions of pounds have been pledged to help rebuild the infrastructure of the countries affected As well as money, programmes have been set up to rebuild houses and help people get back to work A tsunami warning system has been put in place in the Indian Ocean Disaster management plans have been put in place in some countries and volunteers have been trained so that local people know what to do if a tsunami happens again

4 River discharge Discharge the volume of water that flows through the river in a given time, measured in cumecs cubic metres per second (m 3 /s) Hydrographs Hydrographs show how the discharge at a certain point in a river changes over time Storm hydrographs show the changes in river discharge around the time of a storm Peak precipitation the highest amount of rainfall in the period of time Peak discharge the highest discharge in the period of time looked at Lag time the delay between peak precipitation and peak discharge Rising limb the increase in river discharge as rainwater flows into the river, often very steep Falling limb the decrease in river discharge as the river returns to its normal level, not as steep Lag time happens because most rain water does not directly fall into the river channel there is a delay before rainwater gets into the channel If the lag time is short, the water has got there overland (surface runoff) if the lag time is long, the water has got there by soaking into the ground (infiltration) Page 18 of 76 Factors affecting river discharge Amount and type of rainfall lots of rain and short, heavy periods of rainfall means that there is more runoff, which decreases lag time and increases the river discharge Temperature hot, dry conditions and cold, freezing conditions both result in hard ground, increasing runoff, which decreases lag time and increases discharge Previous weather conditions after lots of rain, the soil can become saturated, no more rainfall will be able to infiltrate into the soil, causing the surface runoff to increase, which decreases lag time and increases discharge Relief if there are steep slopes then there will be more runoff, decreasing lag time and increasing the discharge of the river Rock type if the rock is permeable and porous then the water can easily infiltrate and flow along cracks meaning that there will be less runoff, increasing lag time and decreasing discharge. If the rock is impermeable then the water is unable to infiltrate it so there is more runoff, decreasing lag time and increasing discharge Land use urban areas have drainage systems and are covered in impermeable surfaces such as tarmac that increases runoff, decreases lag time and increases discharge. If there is lots of vegetation then more of the water will be stopped, reducing runoff Drainage basin if it is dendritic or small, the water will get into the streams quicker, decreasing lag time and increasing discharge. Also if the drainage basin is elongated, it will take longer for the water to reach the main river channel, increasing lag time and decreasing discharge

5 Hard and soft engineering Hard engineering man-made structures built to control the flow of rivers and reduce flooding Soft engineering schemes set up using knowledge of a river and it's processes to reduce the effects of flooding Method What it is Benefits Disadvantages Dams and reservoirs (hard) Dams are built across the rivers usually in the upper course. This forms a reservoir behind the dam Reservoirs store water, especially during periods of prolonged or heavy rain, which reduces the risk of flooding The water in the reservoir is used as drinking water and can be used to generate hydroelectric power (HEP) Damns are very expensive to build Creating a reservoir can flood existing settlements Eroded material is deposited in the reservoir and not along the river's natural course so farmland downstream can be less fertile Channel straightening (hard) Flood warnings (soft) Preparation (soft) The rivers course is straightened meanders are cut out by building artificial straight channels The Environment Agency warns people about possible flooding through TV, radio, newspapers and the internet Buildings are modified to reduce the amount of damage a flood could cause. People make plans for what to do in a flood they keep important documents and items like touches and blankets in a handy place Water moves out of the area more quickly because it doesn't have to travel as far reducing the risk of flooding The impact of flooding is reduced warnings give people time to move possessions upstairs, put sandbags in position and to evacuate The impact of flooding is reduced buildings are less damaged and people know what to do when a flood happens People are also less likely to worry about the threat of floods if they're prepared Flooding may happen downstream of the straightened channel instead, as the water is carried there faster There's more erosion downstream because the water is flowing faster Warnings don't stop a flood from happening Living in a place that gets lots of warnings could make it difficult to get insurance People may not hear or have access to warnings Page 22 of 76 Preparation doesn't guarantee safety from a flood It could give people a false sense of security It's expensive to modify homes and businesses Flood plain zoning (soft) Restrictions prevent building on parts of a flood plain that are likely to be affected by a flood The risk of flooding is reduced impermeable surfaces aren't created The impact of flooding is reduced there aren't any houses or roads to be damaged The expansion of an urban area is limited if there aren't any other suitable building sites It s no help in areas that have already been built on

6 CASE STUDY UK Reservoir: Rutland Background The dam was built and Rutland Water was created during the 1970s The reservoir covers a 12 km 2 area and is filled with water from two rivers the River Welland and the River Nene Rutland Water was designed to supply the East Midlands with more water enough to cope with rapid population growth in places such as Peterborough Areas around the reservoir are also used as a nature reserve and for recreation Impacts Economic The reservoir boosts the local economy it s a popular tourist attraction because of the wildlife and recreation facilities Around 6 km 2 of land was flooded to create the reservoir, including farmland, so some farmers lost their livelihoods and their businesses Social Lots of recreation activities take place on and around the reservoir (sailing, birdwatching, cycling) Many jobs have been created to build and maintain the reservoir, and to run the nature reserve and recreational activities Schools use the reservoir for educational visits Two villages were demolished to make way for the reservoir Environmental Rutland Water is a Site of Special Scientific Interest (SSSI) an area where wildlife is protected Hundreds of species of birds live around the reservoir and tens of thousands of waterfowl go to Rutland over the winter A variety of habitats are found around the reservoir marshes, mudflats and lagoons this means lots of different organisms live in or around the reservoir A large area of land was flooded to create the reservoir, which destroyed some habitats Sustainability The supply of water from the reservoir needs to be sustainable people should be able to get all the water they need today, without stopping the people in the future from having enough water People can t deplete the water supply or damage the environment too much, or the supply won't be the same in the future To use the reservoir in a sustainable way, people can only take out as much water as is replaced by the rivers that supply it so the supply will stay the same for the future Page 25 of 76

7 Glaciers Formation Snow is collected in a small hollow on the mountain side and it does not totally melt during the summer months and the collection of snow builds up and gets compacted (100kg/m 3 ) which is called nivation The compacted snow then becomes denser and forms firn ice (500kg/m 3 ) Over time this gradually becomes denser and forms glacier ice (900kg/m 3 ) This rotates in the hollow, eroding the back wall through plucking and the base by abrasion The erosion creates an arm chair shape called a corrie with a rock lip from stopping it moving down the mountainside When it has got big enough, it will go over the rock lip and gradually move downhill as a glacier The glacial budget Page 27 of 76 The zone of accumulation is where ice is added to the glacier which can be by snowfall or avalanches The zone of ablation is where ice is removed which can be by evaporation, melting or calving The glacial budget is the balance between accumulation and ablation in a year which shows if the glacier is advancing or retreating: A positive glacial budget is when accumulation is greater than ablation so it gets larger and the snout advances downhill A negative glacial budget is when ablation is greater than accumulation so the glacier gets smaller and the clout retreats up the valley If there is the same amount of accumulation and ablation over a year, the glacier stays the same size and the position of the snout does not change Glaciers advance and retreat seasonally: in the summer there is more ablation so they retreat; in the winter there is more accumulation so they advance Since 1950 most glaciers have had a negative glacial budget, so they have been retreating. This is due to the climate change

8 Along sides of main roads and are often inter-war semi-detached houses and shops Maybe some modern housing estates Houses usually have gardens and garages with areas of open space between them The more recent and expensive housing is in the outer suburbs, where the density of housing tends to be lower Expanding outwards into rural-urban fringe Rural-urban fringe The rural-urban fringe is the part right at the edge of the city, where there are both urban land uses (factories) and rural land uses (farming). Here you tend to find fewer and larger houses. Sometimes land use in each part does not match the model as all cities are slightly different. For example, in cities in countries such as France, Italy and Sweden, the inner city areas are where the wealthier middle-class people live and the suburbs tend to be the more deprived areas. Land use for each part of the city can also change over time, for example: In recent years a lot of shopping centres have been built in out-of-town locations in the UK which has caused shops in the CBDs to close down. Inner city tower blocks have been removed and replaced by housing estates on the rural-urban fringe. New housing estates are often built on Brownfield sites in the inner city instead of toward the edges of the city. LEDC Cities in LEDCs can be totally different. They tend to be irregular, haphazard, unorganised and varied. They are often a quite complex pattern and hard to generalise but can be that: The closest ring to the CBD isn t a zone of old industry and cheap housing but instead it s a highclass residential area, with modern expensive apartments (e.g. Mumbai) Cheaper housing is found further out in the city Poor quality housing can be found right next to the expensive area Shanty towns are often found on the very edge of the city Industry tends to be found along the main roads into the city. Page 49 of 76

9 Traffic There are an increased number of cars on the roads of in richer countries. This causes many problems that discourage people from visiting and shopping in the city: More air pollution, which damages health More road accidents Air pollution also damages buildings More traffic jams and congestion Some of the solutions to help reduce traffic and its impacts in the city are: Improving public transport encouraging people to use public transport instead of cars (also helped with lower prices), which reduces traffic congestion, air pollution, traffic jams and accidents. This also includes park-and-ride schemes so that cars stay in the outer parts of the city and the people then go in on buses Increased parking charges in city centres this discourages car use as people do not want to pay so much for parking, making it more likely that people use public transport instead. Congestion charges and low emission zones also have the same effect, making people pay to enter certain areas of the city Bus lanes these speed up bus services which means that people are more likely to use them. Pedestrianisation of central areas this removes traffic from the main shopping streets, which reduces the number of accidents and pollution levels. It also makes these areas more attractive to shoppers Cultural mix Cities usually have a variety of people from different ethnic backgrounds but there is often ethnic segregation. The reasons for this include: People prefer to live close to others with the same background and religion, and who speak the same language. People live near to services that are important to their culture, e.g., places of worship. This means that people of the same ethnic background tend to live in the same area. Page 59 of 76 People from the same ethnic background are often restricted in where they can live in the same way, e.g., because of lack of money, so they all end up in the same place. Strategies to support the multicultural nature of urban areas aren t aimed at forcing people to mix. The strategies make sure that everyone has equal access to services, like healthcare and education. Some of the ways to do this include: Making sure that everyone can access information about the different services, e.g., by printing leaflets in a variety of languages. Improving communication between all parts of the community, e.g., by involving the leaders of different ethnic communities when making decisions. Providing interpreters at places like hospitals and police stations. Making sure there are suitable services for different cultures. For example, in some cultures it is unacceptable to be seen by a doctor of the opposite sex, so alternatives should be provided.

10 Environmental issues Rapid urbanisation and industrialisation can cause a number of environmental problems: Waste disposal - People in cites create a lot of waste and if this is not disposed of properly then it can damage people s health and the environment, especially if it is toxic waste. In richer countries waste is disposed of by burning it or burying it in landfill sites and the amount of waste is also reduced by recycling schemes. In poorer countries they struggle to dispose of the waste because of a number of reasons: Money the poorer countries cannot afford to dispose of the waste safely for example toxic waste has to be treated and this can be expensive. There are often more urgent problems that require the limited funds of the country, e.g., healthcare Infrastructure - poorer countries don t have the infrastructure needed, e.g., poor roads in squatter settlements mean that waste disposal lorries can t get in to collect rubbish Scale the problem is huge, a large city will generate thousands of tonnes of rubbish every day Air pollution coming from burning fuels, vehicle exhausts and factories It can lead to acid rain which damages buildings and vegetation The fumes themselves can cause health problems such as headaches and bronchitis Some pollutants damage the ozone layer, which protects us from the sun s harmful rays It can be managed by setting air quality standards for industries and constantly monitoring levels of pollutants to check they are safe Water pollution pollutants can also get carried into rivers and streams, e.g., sewage, which can cause serious health problems and can also harm the wildlife Water pollution can kill fish and other aquatic animals, which disrupts the food chains Harmful chemicals can build up in food chains and poison humans who eat fish from polluted water Contamination of water supplies with sewage can spread diseases like typhoid It can be managed by building sewage treatment plants and passing laws forcing factories to remove pollutants from their waste water Page 62 of 76

11 ICT and call centres Improvements in communication Improvements in ICT and transport have increased globalisation by increasing trade and investment: ICT Improvements include , internet, mobile phones and phone lines that can carry more information and faster This has made it quicker and easier for businesses all over the world to communicate with each other, no time is lost and it is really efficient Transport Improvements include more airports, high speed trains and larger ships This has made it quicker and easier for people all over the world to communicate with each other face to face It has made it easier for companies to get supplies from all over the world and to distribute their product worldwide they don't have to be located near to their suppliers or product market anymore Call centres Improvements in ICT mean that it is just as easy for people to phone a faraway country as it is to phone people in their own country For this reason, a lot of call centres are now based abroad because labour is cheaper, which reduces the running costs Development of call centres in India About 10% of the population speak English fluently About 80% of the people living in towns are literate and 18% of these are graduates Operating costs are 10-60% lower than in the UK Salaries are lover; 1,200 per year in contrast to 12,000 per year in the UK Low staff turnover, working nine-hour shits at times to fit in with origin country or origin Development in ICT allows fast and clear communication Page 66 of 76 Localised industrial regions Improvements in ICT and transport have enabled some industries to develop around a specific region that s useful to them, but still have the ability for global connections

12 CASE STUDY Renewable Resources: India Biogas Background Population of 1.2 billion Access to electricity in urban areas is 93%, in rural areas it is only 50% 400 million people do not have electricity at all Energy source in 2007 Coal and peat 40.8% Combustable renewables and waste 27.2% Oil 23.7% Natural gas 5.6% Hydro-Electric Power 1.8% Nuclear 0.7% Other renewables 0.2% Development project ASTRA (Application of Science and Technology in Rural Areas) is a major development project in India Problems found by ASTRA: Rural families spent hours collecting fuel and water and preparing and cooking food Most commonly used fuel was wood but with the increasing population, suitable fire wood was becoming scarcer so dried cow dung was used instead Women and girls did most of the domestic work, which left little time for school Solution immediate technology and appropriate technology Instead of burning cow dung like wood, it can be used to produce biogas The biogas can then be used for cooking and powering electricity generators Benefits Women and children gain about 2 hours a day so there is more time to go to school About 80% of families use this extra time to earn extra money The slurry that is left over can be used as a fertiliser as it is high in nutrients Cattle are kept in compounds so collecting the dung is relatively easy Many villagers use the biogas to power electricity generators that can then be used to pump Page 75 of 76 water from boreholes and they can also use the electricity for lights