Jerarquía de valores que manifiestan actualmente los

Migration

15.8.1 Movement

Figure 47 Percentage of population which is urbanized, by country, as of 2006.^a

a http://www.unicef.org/sowc08/docs/sowc08_table_

StatisticalTables.pdf

As more and more people leave villages and farms to live in cities, urban growth results. The rapid growth of cities like Chicago in the late 19th century and Mumbai⁷⁴a century later can be attributed largely to rural-urban migration and the demographic transition. This kind of growth is especially commonplace in developing countries⁷⁵.

The rapid urbanisation of the world’s population over the twentieth century is described in the 2005 Revision of the UN World Urbanization Prospects report. The global proportion of urban population rose dramatically from 13% (220 million) in 1900, to 29% (732 million) in 1950, to 49% (3.2 billion) in 2005. The same report projected that the figure is likely to rise to 60% (4.9 billion) by 2030.⁷⁶. Urbanization rates vary between countries. The United States and United Kingdom have a far higher urbanization level than China, India, Swaziland or Niger, but a far slower annual urbanization rate, since much less of the population is living in a rural area.

74 http://en.wikipedia.org/wiki/Mumbai

75 http://en.wikipedia.org/wiki/developing%20country

76 World Urbanization Prospects: The 2005 Revision, Pop. Division, Department of Economic and Social Affairs, UN ˆ{http://www.un.org/esa/population/publications/WUP2005/2005wup.htm}

Urbanization 15.8.2 Causes

Figure 48 Urbanization is not always attributed to high density. In Manila^a, the cost of living has forced residents to live in low quality slum^bs and shanty town^cs

a http://en.wikipedia.org/wiki/Manila b http://en.wikipedia.org/wiki/slum

c http://en.wikipedia.org/wiki/shanty%20town

People move into cities to seek economic opportunities. A major contributing factor is known as

"rural flight⁷⁷". In rural areas, often on small family farms, it is difficult to improve one's standard of living beyond basic sustenance. Farm living is dependent on unpredictable environmental conditions, and in times of drought, flood or pestilence, survival becomes extremely problematic. In modern times, industrialization⁷⁸of agriculture⁷⁹has negatively affected the economy of small and middle-sized farms and strongly reduced the size of the rural labour market. Cities, in contrast, are known to be places where money, services and wealth are centralized. Cities are where fortunes are made and where social mobility is possible. Businesses, which generate jobs and capital, are usually located in urban areas. Whether the source is trade or tourism, it is also through the cities that foreign money flows into a country. Thus, as with immigration generally, there are factors thatpushpeople out of rural areas andpullthem into urban areas.

There are also better basic services as well as other specialist services in urban areas that aren't found in rural areas. There are more job opportunities and a greater variety of jobs. Health is another major factor. People, especially the elderly are often forced to move to cities where there are doctors and hospitals that can address their health needs. Other factors include a greater variety of entertainment

77 http://en.wikipedia.org/wiki/rural%20flight 78 http://en.wikipedia.org/wiki/Factory%20farming 79 http://en.wikipedia.org/wiki/agriculture

(e.g., restaurants, movie theaters, theme parks, etc.) and better quality of education in the form of universities. Due to their high populations, urban areas can also have much more diverse social communities allowing others to find people like them when they might not be able to in rural areas.

These conditions are heightened during times of change from a pre-industrial society to an industrial one.

15.8.3 Economic effects

As cities develop, effects can include a dramatic increase in costs, often pricing the local working class⁸⁰ out of the real estate market. For example, Eric Hobsbawm's book The age of the revo-lution: 1789–1848(published 1962 and 2005) chapter 11, stated "Urban development in our period [1789–1848] was a gigantic process of class segregation, which pushed the new labouring poor into great morasses of misery outside the centres of government and business and the newly specialised residential areas of the bourgeoisie. The almost universal European division into a 'good' west end and a 'poor' east end of large cities developed in this period." This is likely due the prevailing south-west wind which carries coal smoke and other airborne pollutants downwind, making the western edges of towns preferable to the eastern ones. Similar problems now affect the developing world; rising inequality results from rapid urbanization. The drive for growth and efficiency can lead to less equitable urban development⁸¹.

Urbanization is often viewed as a negative trend, but can in fact, be perceived simply as a natural occurrence from individual and corporate efforts to reduce expense in commuting and transportation while improving opportunities for jobs, education, housing, and transportation. Living in cities permits individuals and families to take advantage of the opportunities of proximity, diversity, and marketplace competition.⁸²

15.8.4 Environmental effects

One environmental concern associated with urbanization is the urban heat island⁸³. The urban heat island is formed when industrial and urban areas are developed and heat becomes more abundant.

In rural areas, a large part of the incoming solar energy is used to evaporate water from vegetation and soil. In cities, where less vegetation and exposed soil exists, the majority of the sun’s energy is absorbed by urban structures and asphalt. Hence, during warm daylight hours, less evaporative cooling in cities allows surface temperatures to rise higher than in rural areas. Additional city heat is given off by vehicles and factories, as well as by industrial and domestic heating and cooling units.⁸⁴

80 http://en.wikipedia.org/wiki/working%20class

81 Grant, Ursula (2008) Opportunity and exploitation in urban labour markets http://www.odi.org.uk/

resources/download/1969.pdfLondon: Overseas Development Institute ˆ{http://en.wikibooks.

org/wiki/Overseas%20Development%20Institute}

82 Glaeser, Edward. 1998. "Are Cities Dying?" The Journal of Economic Perspectives. 12(2):139–160 83 http://en.wikipedia.org/wiki/urban%20heat%20island

84 Park, H.-S. (1987). Variations in the urban heat island intensity affected by geographical environments. Environmental Research Center papers, no. 11. Ibaraki, Japan: Environmental Research Center, The University of Tsukuba.

Urbanization This effect causes the city to become 2 to 10^oF (1 to 6^oC) warmer than surrounding landscapes.⁸⁵. Impacts also include reducing soil moisture and intensification of carbon dioxide emissions.⁸⁶ The effects of urbanization may be an overall positive for the environment. Birth rates of new urban dwellers fall immediately to the replacement rate (2.1), and keep falling. This can prevent overpopulation (see discussion below). Additionally, it puts a stop to destructive subsistence farming techniques, like slash and burn⁸⁷agriculture. Finally, it minimizes land use by humans, leaving more for nature.⁸⁸

15.8.5 Changing forms of urbanization

Different forms of urbanization can be classified depending on the style of architecture and planning methods as well as historic growth of areas. In cities of the developed world⁸⁹urbanization tradi-tionally exhibited a concentration of human activities and settlements around the downtown area.

Recent developments, such as inner-city redevelopment schemes, mean that new arrivals in cities no longer necessarily settle in the centre. In some developed regions, the reverse effect, originally called counter urbanisation⁹⁰has occurred, with cities losing population to rural areas, and is particularly common for richer families. This has been possible because of improved communications and means of transportation, and has been caused by factors such as the fear of crime and poor urban environments. Later termed"white flight⁹¹", the effect is not restricted to cities with a high ethnic minority population. When the residential area shifts outward, this is called suburbanization⁹². Some research suggests that suburbanization has gone so far to form new points of concentration outside the downtown both in developed and developing countries such as India⁹³.

Urbanization can be planned or organic. Planned urbanization, (e.g., planned communities⁹⁴), is based on an advanced plan, which can be prepared for military, aesthetic, economic or urban design⁹⁵ reasons. Organic urbanization is not organized and happens haphazardly. Landscape planners⁹⁶are responsible for landscape infrastructure (e.g., public park⁹⁷s, sustainable urban drainage systems⁹⁸, greenways⁹⁹, etc.) which can be planned before urbanization takes place, or afterward to revitalize an area and create greater livability¹⁰⁰within a region. Planned urbanization and development is the aim of the American Institute of Planners¹⁰¹.

85 "Heat Island Effect" ˆ{http://www.epa.gov/heatisland/}

86 "Heating Up: Study Shows Rapid Urbanization in China Warming the Regional Climate Faster than Other Urban Areas"http://gtresearchnews.gatech.edu/newsrelease/china-climate.htm

87 http://en.wikipedia.org/wiki/slash%20and%20burn 88 Brand, Stewart. Whole Earth Discipline.

89 http://en.wikipedia.org/wiki/Developed%20country 90 http://en.wikipedia.org/wiki/counter%20urbanisation 91 http://en.wikipedia.org/wiki/white%20flight

92 http://en.wikipedia.org/wiki/suburbanization

93 Sridhar, K. 2007. Density gradients and their determinants: Evidence from India. Regional Science and Urban Economics 37(3):314-344

94 http://en.wikipedia.org/wiki/planned%20community 95 http://en.wikipedia.org/wiki/urban%20design 96 http://en.wikipedia.org/wiki/Landscape%20planning 97 http://en.wikipedia.org/wiki/public%20park

98 http://en.wikipedia.org/wiki/sustainable%20urban%20drainage%20systems 99 http://en.wikipedia.org/wiki/Greenway%20%28landscape%29

100 http://en.wikipedia.org/wiki/livability

101 http://en.wikipedia.org/wiki/American%20Institute%20of%20Planners