Urbanisation In Medcs
A number of problems in Mexico City have been created by rapid urban growth, some of which are similar to those experienced by the UK in the 19th century, the period of the industrial revolution.
Mexico is situated between Belize and the USA; the capital is in the centre of the country and growth is constricted towards the south and west due to high rugged mountains. Mexico City is built on a series of old lakebeds almost 2400m above sea level; the majority of the lakes in the valley were drained by the late 18th century. Although the lakes were drained there is still a store of water underground, this means that the city is sinking by 5-40cm per year. Due to the city being built on relatively unstable grounds, the lake sediments amplify earthquakes experienced in the area. In September 1985 an earthquake caused a death toll of 10,000.
With an elevated mountain rimmed basin, Mexico City is prone to temperature inversions where pollutants, particularly from burning fossil fuels are trapped and cannot disperse, this creates a layer of smog over the city. This was a very common occurrence in UK cities of the industrial revolution, for example Manchester.
The industrial revolution started in the late 1700’s when Richard Arkwright introduced the first mechanical textile machines into factories. Factories were extremely polluting as the machines were run on coal burning fires but at the time this was not seen as a concern as it was a very profitable business making factory owners very wealthy just as landowners were in the rural areas of the UK. Growth of the cities followed the introduction of the factories; mechanisation of farming had caused large unemployment in rural areas. Factories needed a workforce and labourers were paid better in this industry than farming. Later came the introduction of the iron industry creating more work but also more pollution for the cities.
Mexico City is in a similar stage as this period of the industrial revolution; over 40,000 factories in the city provide jobs to the population whilst creating this environmental concern in the process. However if Mexico wants to become a stable country, which is sustainable, then it needs to go through this process. Unfortunately now that we no of the problems that pollutants cause it is difficult to watch Mexico do this to the environment.
Factors explaining growth of a city can be divided into five main reasons. Firstly economic influence, areas of a city will expand if attractions are in a central location and accessible for services, businesses and shops. The high demand for space in central areas pushes up property and land prices. As businesses increase in size and number the area covered by the CBD will expand, therefore causing residential areas to increase in size, as the workforce of these companies will live nearby.
Often people cannot afford to spend a lot of money on travel expenses and therefore will live close to where they work to reduce their costs. This means that you get a high concentration of people living in a specific area. Proximity to certain urban areas can affect where people live. For example, if a polluting factory is opened, it may deter people from living in that area and inadvertently cause an increase in the number of people living somewhere else. Making the problems being experienced here to perhaps become more severe.
Secondly, political control, restrictions may be in place to allow growth in some areas but not others, for example a green belt system. The purpose of a green belt is to stop building in that area. Private companies owning land can determine who they sell land to and who they refuse. Redlining areas can be instructed by political bodies to enforce that people do not live in specific areas. Redlining an area can simply be done by not allowing someone to borrow money to buy a house in that area.
Thirdly, socio-economic segregation, people often live in areas of similar ethnic groups, life style and family types. For example in Mexico City there are specific areas where the elite live and other areas where the poor live. The elite tend to be found in areas of wealthy suburbanites in the south west of the city where there is the least pollution, furthest from industries with the best commercial services, transport networks and medical and healthcare options. Where as the poorer population live in the northeast close to the industrial areas and CBD where there is the worst pollution and 40-66% live in informal settlements.
Fourthly, migration, there are a range of strong push and pull factors to Mexico City from rural areas in Mexico. Approximately 3000 people migrate to Mexico City each day from surrounding states, for example Hidalgo. The push and pull factors can be divided up into economic, political, social and environmental.
A political pull factor is that education is more available in the city and older children often can attend whilst younger ones work with parents in the informal sector. Political push factors are that there is a lack of basic services in rural areas, 80% without running water and poor communications and that there has been very little investment in projects benefiting subsistence farmers.
An example of an economic pull factor is that relatives already living in the city provide networks of information on employment and accommodation, 44% of migrants rely on help such as this to get them started. Some examples of economic push factors include, unemployment in rural areas, large landowners dominate the land and give few benefits to farmers, and rural farmers have variable yields and cannot afford pesticides.
Examples of social pull factors include, lower mortality rates in the city due to more services such as healthcare, glamorised perception of urban life, women are more able to migrate due to greater independence, more opportunities in the city. Social push factors are dominated by the rapid rate of natural increase, which causes stress on the food supplies.
There are no environmental pull factors; it is well known that Mexico City has one of the worst pollution records in the world however some rural areas are so dire that it is the only solution. For example 80% of soils are poor and subject to soil erosion and desertification.
Finally, natural increase, there is a reduction is the number of people dying and an increase in the number of births, approximately 30/1000 crude birth rate to 10/1000 crude death rate.
With the city growing exponentially, being ten times larger than it was in 1940 there are a range of problems that are difficult to avoid in an LEDC. There is no public transport in Mexico City meaning there is 3.5 million privately owned vehicles on the road, this creates congestion throughout the road networks and high levels of carbon monoxide and sulphur dioxide are released. With the addition of 40,000 factories producing 12,000 tonnes of gases per day, the mixture of pollutants and cool air from the surrounding mountains causes a temperature inversion creating a thick layer of smog over the city that is extremely bad for your health; there is a high incidence of respiratory problems.
Similar problems were seen in Manchester in the early 19th century where factory chimneys and domestic coal fires created a permanent blanket of smoke and acid rain creating numerous diseases including bronchitis, influenza, asthma and pneumonia. It has been said that breathing the air in Mexico City is the equivalent of smoking sixty cigarettes a day. In 1994 the World Health Organisation (WHO) declared that the quality of the air in Mexico City was only acceptable on twenty days of the year.
Due to the city being built on dried lakebeds where huge amounts of waste matter has been dumped over the years on open sites there are new problems of winds uplifting dust and spreading it over the south east and north east adding to the smog situation.
As 99% of lakes in Mexico have been drained it means that water has to be pumped from 150km to supply Mexico City with its requirements, 66,000 litres are consumed per second.
In the early 19th century Manchester experienced an extremely rapid increase in population size, while London’s population doubled, Manchester’s trebled. In 1811 Manchester had a population of 89,068 by 1851 the population had risen to 303,382 people. This created an extreme problem with availability of housing and quality of living standards. Population density was extremely high and many people shared poorly constructed houses with very little sanitation and no water supply. This can be seen in Mexico City today, here the population density has risen to 5487 persons per km2 due to the mass numbers migrating to the city on a daily basis and therefore there is not adequate housing available. This means that shanty towns have developed where people live in shacks constructed from corrugated iron and wood. Where people are living in proper houses it often overcrowded, this is 44% of houses in Mexico City.
With a large population comes a large waste disposal crisis; in Mexico City approximately 90% of hazardous waste is release into the sewage systems, which are contaminating the water supply. This has further affect on the population when the water is used on the growing crops. A result of the contamination is that fruit and vegetables contain a high level of lead. Many babies born suffer some problem caused by lead poisoning.