MEDC Urban Issues

With references to a city you have studied in class, outline the issues that it faces, and what the causes of these issues are.

LA

An example of a city with lots of urban issues is Los Angeles. LA is a densely populated Mega City, stretching out for over 498 square miles with a growing population of over 13million. The city is located in the state of California on the west coast of America between San Francisco and the Mexican border.

LA has a high population density, partially due to its geography. LA is squeezed between the Pacific Ocean and the Rocky Mountains, so every available space is used. This limit of space has lead to overcrowding in many areas, especially poorer regions where poor immigrants move there, then can’t afford to move out. Also, because there is so little space for expansion, in many areas there are poor public services as the government hasn’t got the space or the money to build new train lines/stations or improve bus routes on congested roads by for example building another lane. Competition for land and other prime sites means property is expensive to buy or rent. As well as this, freeways built to give access everywhere to drivers, can no longer cope with the volume of traffic so suburbaners who work downtown face long and expensive journeys, as well as increasing the amount of air pollution.

All of this lead to the 1992 race riots, where the high number of immigrants fought back against their poor services in their area and the total lack of government spending. Urbanisation caused 85% of La’s immigrants to be from Mexico or the Asian Pacific Rim countries, and they were looking for a better quality of life in the “city of Dreams”. These people had to take low paid jobs and because they had little money they were forced to live in poorer districts such as Watts, where everything including things such as public services were not of a quality good enough compared to that of places such as Malibu. The riots caused 572 injuries, 25 deaths and over a thousand fires to blaze across the city. Unsurprisingly, the city has a high incidence of crime, including gang warfare where the mix of cultures in the city clash and drug problems, imported from other states or Mexico.

Due to this immigration, LA’s population density has increased rapidly. The amount of people in the area has amounted to high levels of air pollution. Around 13million people relying on cars means that a lot of pollution is produced. Between 60 and 80% of LA’s air pollution comes from Cars and other forms of public transport on the road. This problem is made worse by the fact that because of LA’s geography, the pollution gets trapped over the city as it cannot escape over the Rocky Mountains. This permanent smog over the city causes many problems, but the main ones are that the C02 causes global warming, it corroded and damages all sorts of materials, especially things which buildings there are made of e.g. metal so they need constant repairs, the fumes from diesel cars can cause cancer, crops and fish are killed by acid rain and the fumes from cars also causes photochemical smog to form which causes bronchitis, lung cancer or stops the proper development of the lungs in children.

This problem is not helped by Natural Hazards. The San Andres fault line runs right through the middle of the city. This causes frequent earthquakes which cannot be helped, and there is only so much architects can do in designing buildings so they withstand the earthquakes. So many people loose there lives, are injured or roads and buildings are destroyed amounting to a large re-building cost when an earthquake occurs. Another natural problem is that LA was built in a dessert-like land. This means there is very little water and LA has to rely on Arizona for its large supply. If this supply ever ran out or damaged many problems would occur. Finally, there are frequent landslides in the region caused by earthquakes, heavy rain, deforestation, fires or too much building on fragile land. This destroys homes and other buildings and endanger lives.

All of these problems have lead to a rapid increase in the growth of edge cities. This is where counter-urbanisation creates new smaller settlements where office buildings and houses are built on the edge of LA, over 50km from downtown area. They normally are made off of motorway junctions as this gives road access to the city. As well as the push factors named above, the pull factors for the edge cities are that there are better home and job prospects, less commuting, can escape pollution and congestion in a better environment and lower land and housing costs. These edge cities have all the facilities you would expect except they quite often lack entertainment such as sport centres or cinemas. It is only the richer proportion of the population that move as they are the only ones who can afford to.

Hostile Earth (Part 1)

In this mini-series we’ll be exploring the destructive side of the Earth, its effects and how we can help to protect ourselves. (This will also cover everything you need to know for Unit 2 of  AQA GCSE Geography!)

Plate Margins

Conservative

  • 2 plates slide past each other, travelling in opposite directions
  • Activity: violent earthquakes
  • Example: San Andreas Fault in California (Pacific & North American plates)

Destructive

  • An oceanic plate moves towards a continental plate, but because it is heavier it sinks and is destroyed, forming deep-sea trenches  and island arcs. Volcanoes also form as the extra magma created from the destroyed oceanic plate is under pressure and is forced upwards through the rock.
  • Activity: violent volcanic & violent earthquakes
  • Example: Chile (Nazca & South American plates)

Constructive (aka Sea-Floor Spreading)

  • 2 plates move apart forming new oceanic crust as well as mid-ocean ridges with volcanoes
  • Activity: gentle volcanic and gentle earthquakes
  • Example: Mid-Atlantic Ridge (e.g. Iceland) (North American & Eurasian plates)

Collision

  • 2 continental crusts collide and as neither can sink they are forced upwards, creating fold mountains
  • Activity: violent earthquakes
  • Example: The Himilayas (Eurasian & Indo-Australian plates)

MEDC Case Study – Kobe, Japan

  • Plate Margin: Destructive
  • Plates: Eurasian & Phillipenes
  • Location: Urban
  • Local Date & Time: 17th January 1995 05:46 a.m.
  • Magnitude: 7.2
  • Primary effects: 200,000 buildings collapsed, 3/4 all quays destroyed, 10 bridges along the bullet train route collapsed, 1 km of Hanshin highway collapsed
  • Secondary effects: 5,500 dead, 40,000 injured, 230,000 homeless when temps averaged -2 degrees, fires from ruptured gas/electricity mains, grid-locked roads, lack of water supplies, industries shut down

LEDC Case Study – Sichuan, China

  • Plate Margin: Conservative
  • Plates: Eurasian & Indo-Australian
  • Location: Rural
  • Local Date & Time: 12th May 2008 02:30 p.m.  
  • Magnitude: 7.9
  • Primary effects: 7,000 classrooms and most buildings collapsed, communication (e.g. phone lines) destroyed, landslides, hospitals destroyed
  • Secondary effects: 70,000 dead, 40,000 injured, 4.8 million homeless, 70% roads blocked, 46 million affected in total, 18,000 still missing presumed dead, $86 billion damage, isolation of villages in remote areas

Reducing the risks from earthquakes

Key definitions

  • Prediction: the use of science/technology to monitor techtonic activity
  • Preparation: creating emergency plans to implement once the disaster has struck
  • Planning: e.g. building design – earthquake-proofing buildings in urban areas to reduce damage, injuries & death
  • Retrofitting: addition of new technology to older buildings
  • Appropriate technology: technology designed with consideration of intended community

In an MEDC…

  • Computer controlled counterweight on roof
  • Cross-bracing to add strength and prevent twisting
  • Automatic window shutters stopping shattered glass#
  • Automatic sprinklers to prevent fires

In an LEDC…

  • Roof made of reinforced concrete
  • Hollow concrete bricks which cause less damage if they fall
  • Foundations made mainly of stone from the remains of previously destroyed buildings
  • Relatively cheap and uses recycled materials

Special Case: Costa Rica

  • Bamboo homes – bamboo is strong but also flexible so less likely buildings will collapse. More environmentally friendly as only 70 hectares of land needed to build 1000 homes compared to 600 hectares of forest.

How to prepare your home:

  • Secure heavy, moveable items of furniture
  • Prepare an earthquake kit
  • Practice earthquake drills (e.g. Disaster Prevention Day in Japan)
  • After the shaking stops check for injuries and check the radio for further instructions
  • Building codes – homes built in at-risk areas must have strong earthquake-proofing

Preperation for and Response to Earthquakes..

MEDC

  • Local services are well trained and regularly have practice drills
  • New buildings comply with strict earthquake planning regulations
  • Emergency earthquake kits packed
  • Education – teach people what to expect in the event of an earthquake
  • Counselling for distressed children
  • Viible identification numbers on roofs to help helicopters assess damage

LEDC

  • Looks to international aid and world-wide charities for help
  • Cremate the dead to prevent disease
  • Airfields that bring in rescue teams and emergency supplies are often too far away
  • Poorly built buildings
  • Limited supplies for a large number of victims
  • Makeshift open-air hospitals
  • Limited funds to cover cost of supplies and rebuilding projects
  • Lack of radio/tv/internet that could communicate with people to allow time to evacuatedanger zones or help manage relief operations

Both

  • Evacuation centres in safe areas
  • Community ready and willing to search for victims/survivors but lacks the appropriate equipment
  • Monitoring movementss in the Earth’s crust
  • Massive disruption to power lines transport and communications