Global urbanization map showing the percentage of urbanization per country in 2015
Guangzhou,
a city of 14.5 million people, is one of the 8 adjacent metropolises
located in the largest single agglomeration on earth, ringing the Pearl River Delta of China.
Mumbai is the most populous city in India, and the eighth most populous city in the world, with a total metropolitan area population of approximately 18.4 million.
Urbanization refers to the population shift from rural to
urban residency, the gradual increase in the proportion of people living
in urban areas, and the ways in which each society adapts to this
change.
It is predominantly the process by which towns and cities are formed
and become larger as more people begin living and working in central
areas.
Although the two concepts are sometimes used interchangeably,
urbanization should be distinguished from urban growth: urbanization is
"the proportion of the total national population living in areas classed
as urban", while urban growth refers to "the absolute number of people
living in areas classed as urban". The United Nations projected that half of the world's population would live in urban areas at the end of 2008. It is predicted that by 2050 about 64% of the developing world and 86% of the developed world will be urbanized. That is equivalent to approximately 3 billion urbanites by 2050, much of which will occur in Africa and Asia.
Notably, the United Nations has also recently projected that nearly all
global population growth from 2017 to 2030 will be absorbed by cities,
about 1.1 billion new urbanites over the next 13 years.
Urbanization is relevant to a range of disciplines, including urban planning, geography, sociology, economics, and public health. The phenomenon has been closely linked to modernization, industrialization, and the sociological process of rationalization.
Urbanization can be seen as a specific condition at a set time (e.g.,
the proportion of total population or area in cities or towns), or as an
increase in that condition over time. So urbanization can be quantified
either in terms of, say, the level of urban development relative to the
overall population, or as the rate
at which the urban proportion of the population is increasing.
Urbanization creates enormous social, economic and environmental
changes, which provide an opportunity for sustainability with the
“potential to use resources more efficiently, to create more sustainable
land use and to protect the biodiversity of natural ecosystems.”
Urbanization is not merely a modern phenomenon, but a rapid and historic transformation of human social roots on a global scale, whereby predominantly rural culture is being rapidly replaced by predominantly urban culture. The first major change in settlement patterns was the accumulation of hunter-gatherers
into villages many thousand years ago. Village culture is characterized
by common bloodlines, intimate relationships, and communal behavior,
whereas urban culture is characterized by distant bloodlines, unfamiliar
relations, and competitive behavior. This unprecedented movement of
people is forecast to continue and intensify during the next few
decades, mushrooming cities to sizes unthinkable only a century ago. As a
result, the world urban population growth curve has up till recently
followed a quadratic-hyperbolic pattern.
Today, in Asia the urban agglomerations of Osaka, Karachi, Jakarta, Mumbai, Shanghai, Manila, Seoul and Beijing are each already home to over 20 million people, while Delhi and Tokyo are forecast to approach or exceed 40 million people. Cities such as Tehran, Istanbul, Mexico City, São Paulo, London, New York City, Lagos and Cairo are, or soon will be, home to over 10 million people each.
History
Historical global urban/rural population trends
From the development of the earliest cities in Mesopotamia and Egypt until the 18th century, an equilibrium existed between the vast majority of the population who engaged in subsistence agriculture in a rural context, and small centers of populations in the towns where economic activity consisted primarily of trade at markets
and manufactures on a small scale. Due to the primitive and relatively
stagnant state of agriculture throughout this period, the ratio of rural
to urban population remained at a fixed equilibrium. However, a
significant increase in the percentage of the global urban population
can be traced in the 1st millennium BCE. Another significant increase can be traced to Mughal India, where 15% of its population lived in urban centers during the 16th–17th centuries, higher than in Europe at the time. In comparison, the percentage of the European population living in cities was 8–13% in 1800.
With the onset of the British agricultural and industrial revolution
in the late 18th century, this relationship was finally broken and an
unprecedented growth in urban population took place over the course of
the 19th century, both through continued migration from the countryside
and due to the tremendous demographic expansion that occurred at that time. In England and Wales,
the proportion of the population living in cities with more than 20,000
people jumped from 17% in 1801 to 54% in 1891. Moreover, and adopting a
broader definition of urbanization, we can say that while the urbanized
population in England and Wales represented 72% of the total in 1891,
for other countries the figure was 37% in France, 41% in Prussia and 28% in the United States.
As labourers were freed up from working the land due to higher
agricultural productivity they converged on the new industrial cities
like Manchester and Birmingham
which were experiencing a boom in commerce, trade and industry. Growing
trade around the world also allowed cereals to be imported from North America and refrigerated meat from Australasia and South America. Spatially, cities also expanded due to the development of public transport systems, which facilitated commutes of longer distances to the city centre for the working class.
Urbanization rapidly spread across the Western world and, since the 1950s, it has begun to take hold in the developing world as well. At the turn of the 20th century, just 15% of the world population lived in cities. According to the UN,
the year 2007 witnessed the turning point when more than 50% of the
world population were living in cities, for the first time in human
history.
Yale University in June 2016 published urbanization data from the time period 3700 BC to 2000 AD, the data was used to make a video showing the development of cities on the world during the time period.
Causes
Population age comparises between rural Pocahontas County, Iowa and urban Johnson County, Iowa, illustrating the flight of young adults (red) to urban centers in Iowa.
The City of Chicago, Illinois is an example of the early American grid system of development. The grid is enforced even on uneven topography.
Urbanization occurs either organically or planned as a result of
individual, collective and state action. Living in a city can be
culturally and economically beneficial since it can provide greater
opportunities for access to the labor market, reduce the time and
expense of commuting and transportation better education, housing and
safety conditions. Condition like density, proximity, diversity, and
marketplace competition are elements of an urban environment that deemed
positive. However, there are also negative social phenomena that arise,
alienation, stress, increased cost of living, and mass marginalization
that are connected to an urban way of living. Suburbanization,
which is happening in the cities of the largest developing countries,
may be regarded as an attempt to balance these negative aspects of urban
life while still allowing access to the large extent of shared
resources.
In cities, money, services, wealth and opportunities are
centralized. Many rural inhabitants come to the city to seek their
fortune and alter their social position. Businesses, which provide jobs
and exchange capital, are more concentrated in urban areas. Whether the
source is trade or tourism, it is also through the ports or banking
systems, commonly located in cities, that foreign money flows into a
country.
Many people move into cities for the economic opportunities, but
this does not fully explain the very high recent urbanization rates in
places like China and India. Rural flight
is a contributing factor to urbanization. In rural areas, often on
small family farms or collective farms in villages, it has historically
been difficult to access manufactured goods, though the relative overall
quality of life
is very subjective, and may certainly surpass that of the city. Farm
living has always been susceptible to unpredictable environmental
conditions, and in times of drought, flood or pestilence, survival may become extremely problematic.
Thai farmers are seen as poor, stupid, and unhealthy. As young people flee the farms, the values and knowledge of rice farming and the countryside are fading, including the tradition of long kek, helping neighbors plant, harvest, or build a house. We are losing what we call Thai-ness, the values of being kind, helping each other, having mercy and gratefulness. — Iam Thongdee, Professor of Humanities, Mahidol University in Bangkok
In a New York Times article concerning the acute migration away from
farming in Thailand, life as a farmer was described as "hot and
exhausting". "Everyone says the farmer works the hardest but gets the
least amount of money". In an effort to counter this impression, the
Agriculture Department of Thailand is seeking to promote the impression
that farming is "honorable and secure".
However, in Thailand, urbanization has also resulted in massive
increases in problems such as obesity. Shifting from a rural environment
to an urbanized community also caused a transition to a diet that was
mainly carbohydrate based to a diet higher in fat and sugar,
consequently causing a rise in obesity.
City life, especially in modern urban slums of the developing world, is
certainly hardly immune to pestilence or climatic disturbances such as
floods, yet continues to strongly attract migrants. Examples of this
were the 2011 Thailand floods and 2007 Jakarta flood. Urban areas are also far more prone to violence, drugs, and other urban social problems. In the United States, industrialization of agriculture has negatively affected the economy of small and middle-sized farms and strongly reduced the size of the rural labour market.
These are the costs of participating in the urban economy. Your increased income is canceled out by increased expenditure. In the end, you have even less left for food. — Madhura Swaminathan, economist at Kolkata’s Indian Statistical Institute
Particularly in the developing world, conflict over land rights due to the effects of globalization
has led to less politically powerful groups, such as farmers, losing or
forfeiting their land, resulting in obligatory migration into cities.
In China, where land acquisition measures are forceful, there has been
far more extensive and rapid urbanization (54%) than in India (36%),
where peasants form militant groups (e.g. Naxalites) to oppose such efforts. Obligatory and unplanned migration often results in rapid growth of slums.
This is also similar to areas of violent conflict, where people are driven off their land due to violence. Bogotá, Colombia, is one example of this.
Cities offer a larger variety of services, including specialist
services not found in rural areas. These services requires workers,
resulting in more numerous and varied job opportunities. Elderly people
may be forced to move to cities where there are doctors and hospitals
that can cater for their health needs. Varied and high quality
educational opportunities are another factor in urban migration, as well
as the opportunity to join, develop, and seek out social communities.
Urbanization also creates opportunities for women that are not
available in rural areas. This creates a gender-related transformation
where women are engaged in paid employment and have access to education.
This may cause fertility to decline. However, women are sometimes still
at a disadvantage due to their unequal position in the labour market,
their inability to secure assets independently from male relatives and
exposure to violence.
People in cities are more productive than in rural areas. An important question is whether this is due to agglomeration effects
or whether cities simply attract those who are more productive.
Economists have recently shown that there exists a large productivity
gain due to locating in dense agglomerations. It is thus possible that agents locate in cities in order to benefit from these agglomeration effects.
Dominant conurbation
The dominant conurbation(s)
of a country can benefit to a greater extent from the same things
cities offer, making them magnets for not just the non-urban population,
but also urban and suburban population from other cities. Dominant
conurbations are quite often primate cities, but do not have to be. For instance Greater Manila
is rather a conurbation than a city: its 20 million overall population
(over 20% national population) make it very much a primate city, but
Quezon City (2.7 million), the largest municipality in Greater Manila,
and Manila (1.6 million), the capital, are not. A conurbation's
dominance can be measured by output, wealth, and especially population,
each expressed as a percentage of an entire country. Greater Seoul is
one conurbation with massive dominance over South Korea, it is home to
50% of the entire national population.
Though Greater Busan-Ulsan (15%, 8 million) and Greater Osaka
(14%, 18 million) exhibit strong dominance in their respective
countries, they are losing population to their even more dominant
rivals, Seoul and Tokyo respectively.
Economic effect
Crowded people on Siam BTS Station on the rush hour in Bangkok, Thailand
As cities develop, effects can include a dramatic increase and change in costs, often pricing the local working class out of the market, including such functionaries as employees of the local municipalities. For example, Eric Hobsbawm's book The age of revolution: 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 laboring poor into great morasses of misery outside the
centers of government and business and the newly specialized 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
resulting from rapid urbanization trends. The drive for rapid urban
growth and often efficiency can lead to less equitable urban
development. Think tanks such as the Overseas Development Institute
have proposed policies that encourage labor-intensive growth as a means
of absorbing the influx of low-skilled and unskilled labor. One problem these migrant workers are involved with is the growth of slums.
In many cases, the rural-urban low skilled or unskilled migrant
workers, attracted by economic opportunities in urban areas, cannot find
a job and afford housing in cities and have to dwell in slums.
Urban problems, along with infrastructure developments, are also
fueling suburbanization trends in developing nations, though the trend
for core cities in said nations tends to continue to become ever denser.
Urbanization is often viewed as a negative trend, but there are
positives in the reduction of expenses 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 and diversity.
While cities have a greater variety of markets and goods than rural
areas, infrastructure congestion, monopolization, high overhead costs,
and the inconvenience of cross-town trips frequently combine to make
marketplace competition harsher in cities than in rural areas.
In many developing countries where economies are growing, the
growth is often erratic and based on a small number of industries. For
young people in these countries barriers exist such as, lack of access
to financial services and business advisory services, difficulty in
obtaining credit to start a business, and lack of entrepreneurial
skills, in order for them to access opportunities in these industries.
Investment in human capital so that young people have access to quality
education and infrastructure to enable access to educational facilities
is imperative to overcoming economic barriers.
Environmental effects
The existence of urban heat islands
has become a growing concern over the years. An urban heat island is
formed when industrial and urban areas produce and retain heat. Much of
the solar energy that reaches rural areas is consumed by evaporation of
water from vegetation and soil. In cities, where there is less
vegetation and exposed soil, most of the sun's energy is instead
absorbed by buildings and asphalt; leading to higher surface
temperatures. Vehicles, factories and industrial and domestic heating
and cooling units release even more heat. As a result, cities are often 1 to 3 °C (1.8 to 5.4 °F) warmer than surrounding landscapes. Impacts also include reducing soil moisture and a reduction in reabsorption of carbon dioxide emissions.
In his book Whole Earth Discipline,
Stewart Brand argues that the effects of urbanization are primarily
positive for the environment. First, the birth rate of new urban
dwellers falls immediately to replacement rate, and keeps falling,
reducing environmental stresses caused by population growth. Secondly,
emigration from rural areas reduces destructive subsistence farming
techniques, such as improperly implemented slash and burn agriculture.
In July 2013 a report issued by the United Nations Department of Economic and Social Affairs
warned that with 2.4 billion more people by 2050, the amount of food
produced will have to increase by 70%, straining food resources,
especially in countries already facing food insecurity due to changing
environmental conditions. The mix of changing environmental conditions
and the growing population of urban regions, according to UN experts,
will strain basic sanitation systems and health care, and potentially
cause a humanitarian and environmental disaster.
Water quality
The
occurrence of eutrophication in bodies of water is another effect large
urban populations have on the environment. When rain occurs in these
large cities, the rain filters down the pollutants such as CO2
and other green house gases in the air onto the ground below. Then,
those chemicals are washed directly into rivers, streams and oceans,
causing a decline in water quality and damaging marine ecosystems.
Eutrophication is a process which causes hypoxic water conditions
and algal blooms that may be detrimental to the survival of aquatic
life. Harmful algal blooms, which produce dangerous toxins, thrive in eutrophic environments that are also rich in nitrogen and phosphorus.
In these ideal conditions, they overtake surface water, making it
difficult for other organisms to receive sunlight and nutrients.
Overgrowth of algal blooms causes a decrease in overall water quality
and disrupts the natural balance of aquatic ecosystems. Furthermore, as
algal blooms die, CO2 is produced, causing a more acidic environment, a process known as acidification.
The oceans surface also has the ability to absorb CO2
from the earths atmosphere as emissions increase with the rise in
urbanization. In fact, it is reported that the ocean absorbs a quarter
of the CO2 produced by humans.
This has been useful to the environment by decreasing the harmful
effects of greenhouse gases, but also further perpetuates acidification.
Changes in pH inhibit the proper formation of calcium carbonate, a
crucial component for many marine organisms to maintain shells or
skeletons.
This is especially true for many species of mollusks and coral.
Regardless, some species have been able to instead adapt or thrive in a
more acidic environment
Food waste
Rapid growth of communities create new challenges in the developed world and one such challenge is an increase in food waste also known as urban food waste.
Food waste is the disposal of food products that can no longer be used
due to unused products, expiration, or spoilage. The increase of food
waste can raise environmental concerns such as increase production of methane gases and attraction of disease vectors. Landfills are the third leading cause of the release of methane,
causing a concern on its impact to our ozone and on the health of
individuals. Accumulation of food waste causes increased fermentation,
which increases the risk of rodent and bug migration. An increase in
migration of disease vectors creates greater potential of disease
spreading to humans.
Habitat fragmentation
Urbanization
can have a large effect on biodiversity by causing a division of
habitats and thereby alienation of species, a process known as habitat fragmentation. Habitat fragmentation does not destroy the habitat, as seen in habitat loss, but rather breaks it apart with things like roads and railways
This change may affect a species ability to sustain life by separating
it from the environment in which it is able to easily access food, and
find areas that they may hide from predation.
With proper planning and management, fragmentation can be avoided by
adding corridors that aid in the connection of areas and allow for
easier movement around urbanized regions.
Depending on the various factors, such as level of urbanization, both increases or decreases in "species richness" can be seen.
This means that urbanization may be detrimental to one species but also
help facilitate the growth of others. In instances of housing and
building development, many times vegetation is completely removed
immediately in order to make it easier and less expensive for
construction to occur, thereby obliterating any native species in that
area. Other times, such as with birds, urbanization may allow for an
increase in richness when organisms are able to adapt to the new
environment. This can be seen in species that may find food while
scavenging developed areas or vegetation that has been added after
urbanization has occurred i.e planted trees in city areas
Health and social effects
When cities don’t plan for increases in population it drives up house and land prices, creating rich (ghettos) and poor ghettos. "You get a very unequal society and that inequality is manifested where people live, in our neighborhoods, and it means there can be less capacity for empathy and less development for all society." — Jack Finegan, Urban Programme Specialist at UN-Habitat
In the developing world, urbanization does not translate into a significant increase in life expectancy. Rapid urbanization has led to increased mortality from non-communicable diseases associated with lifestyle, including cancer and heart disease. Differences in mortality from contagious diseases vary depending on the particular disease and location.
Urban health levels are on average better in comparison to rural
areas. However, residents in poor urban areas such as slums and informal settlements
suffer "disproportionately from disease, injury, premature death, and
the combination of ill-health and poverty entrenches disadvantage over
time."
Many of the urban poor have difficulty accessing health services due to
their inability to pay for them; so they resort to less qualified and
unregulated providers.
While urbanization is associated with improvements in public hygiene, sanitation and access to health care, it also entails changes in occupational, dietary and exercise patterns. It can have mixed effects on health patterns, alleviating some problems and accentuating others.
Nutrition
One such effect is the formation of food deserts. Nearly 23.5 million people in the United States lack access to supermarkets within one mile of their home.
Several studies suggest that long distances to a grocery store are
associated with higher rates of obesity and other health disparities.
Food deserts in developed countries often correspond to areas
with a high-density of fast food chains and convenience stores that
offer little to no fresh food.
Urbanization has been shown to be associated with the consumption of
less fresh fruits, vegetables, and whole grains and a higher consumption
of processed foods and sugar-sweetened beverages.
Poor access to healthy food and high intakes of fat, sugar and salt are
associated with a greater risk for obesity, diabetes and related
chronic disease. Overall, body mass index and cholesterol levels increase sharply with national income and the degree of urbanization.
Food deserts in the United States are most commonly found in low-income and predominately African American neighborhoods. One study on food deserts in Denver,
Colorado found that, in addition to minorities, the affected
neighborhoods also had a high proportion of children and new births. In children, urbanization is associated with a lower risk of under-nutrition but a higher risk of overweight.
Asthma
Urbanization
has also been associated with an increased risk for asthma as well.
Throughout the world, as communities transition from rural to more urban
societies, the number of people effected by asthma increases. The odds
of reduced rates of hospitalization and death from asthmas has decreased
for children and young adults in urbanized municipalities in Brazil.
This finding indicates that urbanization may have a negative impact on
population health particularly affecting people’s susceptibility to
asthma.
In low and middle income countries many factors contribute to the
high numbers of people with asthma. Similar to areas in the United
States with increasing urbanization, people living in growing cities in
low income countries experience high exposure to air pollution, which
increases the prevalence and severity of asthma among these populations. Links have been found between exposure to traffic-related air pollution and allergic diseases.
Children living in poor, urban areas in the United States now have an
increased risk of morbidity due to asthma in comparison to other
low-income children in the United States.
In addition, children with croup living in urban areas have higher
hazard ratios for asthma than similar children living in rural areas.
Researchers suggest that this difference in hazard ratios is due to the
higher levels of air pollution and exposure to environmental allergens
found in urban areas.
Exposure to elevated levels of ambient air pollutants such as nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter with a diameter of less than 2.5 micrometers (PM2.5),
can cause DNA methylation of CpG sites in immune cells, which increases
children’s risk of developing asthma. Studies have shown a positive
correlation between Foxp3 methylation and children’s exposure to NO2, CO, and PM2.5. Furthermore, any amount of exposure to high levels of air pollution have shown long term effects on the Foxp3 region.
Despite the increase in access to health services that usually
accompanies urbanization, the rise in population density negatively
affects air quality ultimately mitigating the positive value of health
resources as more children and young adults develop asthma due to high
pollution rates.
However, urban planning as well as emission control can lessen the
effects of traffic-related air pollution on allergic diseases such as
asthma.
Crime
Historically
crime and urbanization have gone hand in hand. The simplest explanation
is that areas with a higher population density are surrounded by a
greater availability of goods. Committing crimes in urbanized areas is
also more feasible. Modernization has led to more crime as well. There
is a greater awareness of the income gap between the rich and poor due
to modern media. This leads to feelings of deprivation which can lead to
crime. In some regions where urbanization happens in wealthier areas, a
rise in property crime and a decrease in violent crime is seen.
Data shows that there is an increase of crime in urbanized areas.
Some factors include per capita income, income inequality, and overall
population size. There is also a smaller association between
unemployment rate, police expenditures and crime.
The presence of crime also has the ability to produce more crime. These
areas have less social cohesion, and therefore less social control.
This is evident in the geographical regions that crime occurs in. As
most crime tends to cluster in city centers, the further the distance
from the center of the city, the lower the occurrence of crimes are.
Migration is also a factor that can increase crime in urbanized
areas. People from one area are displaced and forced to move into an
urbanized society. Here they are in a new environment with new norms and
social values. This can lead to less social cohesion and more crime.
Physical activity
Although
urbanization tends to produce more negative effects, one positive
effect that urbanization has impacted is an increase in physical
activity in comparison to rural areas. Residents of rural areas and
communities in the United States have higher rates of obesity and engage
in less physical activity than urban residents.
Rural residents consume a higher percent of fat calories and are less
likely to meet the guidelines for physical activity and more likely to
be physically inactive. In comparison to regions within the United States, the west has the lowest prevalence of physical inactivity and the south has the highest prevalence of physical inactivity. Metropolitan and large urban areas across all regions have the highest prevalence of physical activity among residents.
Barriers such as geographic isolation, busy and unsafe roads, and
social stigmas lead to decreased physical activity in rural
environments.
Faster speed limits on rural roads prohibits the ability to have bike
lanes, sidewalks, footpaths, and shoulders along the side of the roads.
Less developed open spaces in rural areas, like parks and trails,
suggest that there is lower walkability in these areas in comparison to
urban areas.
Many residents in rural settings have to travel long distances to
utilize exercise facilities, taking up too much time in the day and
deterring residents from using recreational facilities to obtain
physical activity.
Additionally, residents of rural communities are traveling further for
work, decreasing the amount of time that can be spent on leisure
physical activity and significantly decreases the opportunity to partake
in active transportation to work.
Neighborhoods and communities with nearby fitness venues, a
common feature of urbanization, have residents that partake in increased
amounts of physical activity.
Communities with sidewalks, street lights, and traffic signals have
residents participating in more physical activity than communities
without those features.
Having a variety of destinations close to where people live, increases
the use of active transportation, such as walking and biking.
Active transportation is also enhanced in urban communities where
there is easy access to public transportation due to residents walking
or biking to transportation stops.
In a study comparing different regions in the United States,
opinions across all areas were shared that environmental characteristics
like access to sidewalks, safe roads, recreational facilities, and
enjoyable scenery are positively associated with participation in
leisure physical activity.
Perceiving that resources are nearby for physical activity increases
the likelihood that residents of all communities will meet the
guidelines and recommendations for appropriate physical activity.
Specific to rural residents, safety of outdoor developed spaces and
convenient availability to recreational facilities matters most when
making decisions on increasing physical activity.
In order to combat the levels of inactivity in rural residents, more
convenient recreational features, such as the ones discussed in this
paragraph, need to be implemented into rural communities and societies.
Mental health
Urbanization factors that contribute to mental health
can be thought of as factors that affect the individual and factors
that affect the larger social group. At the macro, social group level,
changes related to urbanization are thought to contribute to social
disintegration and disorganization. These macro factors contribute to
social disparities which affect individuals by creating perceived
insecurity.
Perceived insecurity can be due problems with the physical environment,
such as issues with personal safety, or problems with the social
environment, such as a loss of positive self-concepts from negative
events.
Increased stress is a common individual psychological stressor that
accompanies urbanization and is thought to be due to perceived
insecurity. Changes in social organization, a consequence of
urbanization, are thought to lead to reduced social support, increased
violence, and overcrowding. It is these factors that are thought to
contribute to increased stress.
It is important to note that urbanization or population density alone
does not cause mental health problems. It is the combination of
urbanization with physical and social risk factors that contribute to
mental health problems. As cities continue to expand it is important to
consider and account for mental health along with other public health
measures that accompany urbanization.
Changing forms
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 world
urbanization traditionally exhibited a concentration of human
activities and settlements around the downtown area, the so-called in-migration.
In-migration refers to migration from former colonies and similar
places. The fact that many immigrants settle in impoverished city
centres led to the notion of the "peripheralization of the core", which
simply describes that people who used to be at the periphery of the
former empires now live right in the center.
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 urbanization
has occurred, with cities losing population to rural areas, and is
particularly common for richer families. This has been possible because
of improved communications, and has been caused by factors such as the
fear of crime and poor urban environments. It has contributed to the
phenomenon of shrinking cities experienced by some parts of the industrialized world.
When the residential area shifts outward, this is called
suburbanization. A number of researchers and writers suggest that
suburbanization has gone so far to form new points of concentration
outside the downtown both in developed and developing countries such as
India.
This networked, poly-centric form of concentration is considered by
some emerging pattern of urbanization. It is called variously exurbia,
edge city (Garreau, 1991), network city (Batten, 1995), or postmodern
city (Dear, 2000). Los Angeles is the best-known example of this type of
urbanization. In the United States, this process has reversed as of
2011, with "re-urbanization" occurring as suburban flight due to chronically high transport costs.
Rural migrants are attracted by the possibilities that cities can offer, but often settle in shanty towns and experience extreme poverty. The inability of countries to provide adequate housing for these rural migrants is related to overurbanization,
a phenomenon in which the rate of urbanization grows more rapidly than
the rate of economic development, leading to high unemployment and high
demand for resources. In the 1980s, this was attempted to be tackled with the urban bias theory which was promoted by Michael Lipton.
...the most important class conflict in the poor countries of the world today is not between labour and capital. Nor is it between foreign and national interests. It is between rural classes and urban classes. The rural sector contains most of the poverty and most of the low-cost sources of potential advance; but the urban sector contains most of the articulateness, organization and power. So the urban classes have been able to win most of the rounds of the struggle with the countryside...". — Michael Lipton, author of urban bias theory
Most of the urban poor in developing countries unable to find work,
can spend their lives in insecure, poorly paid jobs. According to
research by the Overseas Development Institute
pro-poor urbanization will require labour-intensive growth, supported
by labor protection, flexible land use regulation and investments in
basic services.'
Urbanization can be planned urbanization or organic. Planned urbanization, i.e.: planned community or the garden city movement, is based on an advance plan, which can be prepared for military, aesthetic, economic or urban design
reasons. Examples can be seen in many ancient cities; although with
exploration came the collision of nations, which meant that many invaded
cities took on the desired planned characteristics of their occupiers.
Many ancient organic cities experienced redevelopment for military and
economic purposes, new roads carved through the cities, and new parcels
of land were cordoned off serving various planned purposes giving cities
distinctive geometric designs. UN agencies prefer to see urban infrastructure installed before urbanization occurs. Landscape planners are responsible for landscape infrastructure (public parks, sustainable urban drainage systems, greenways etc.) which can be planned before urbanization takes place, or afterward to revitalize an area and create greater livability within a region. Concepts of control of the urban expansion are considered in the American Institute of Planners.
As population continues to grow and urbanize at unprecedented rates, new urbanism and smart growth
techniques are implemented to create a transition into developing
environmentally, economically, and socially sustainable cities. Smart
Growth and New Urbanism’s principles include walkability, mixed-use development, comfortable high-density design, land conservation, social equity, and economic diversity. Mixed-use communities work to fight gentrification with affordable housing to promote social equity, decrease automobile dependency to lower use of fossil fuels, and promote a localized economy.
Walkable communities have a 38% higher average GDP per capita than less
walkable urban metros (Leinberger, Lynch). By combining economic,
environmental, and social sustainability, cities will become equitable,
resilient, and more appealing than urban sprawl that overuses land, promotes automobile use, and segregates the population economically.
