URBANIZATION

History of Urbanization

Causes of Urban Growth

Current Urban Problems

Transportation

City Planning

Garden Cities and New Towns

Cities of the Future

Suburbs

Developing Nations

Since the earliest origins, cities have been centers of education, religion, commerce, record keeping, communication, and political power. As cradles of civilization, cities have influenced culture and society far beyond their proportion of the total population.

Since the beginning of the Industrial Revolution, cities have grown rapidly in both size and power. In every developing country, the transition from an agrarian society to an industrial one has been accompanied by urbanization, an increasing concentration of the population in cities and a transformation of land use and society to a metropolitan pattern of organization.

Cities are cultural and racial melting pots in which information and technology are exchanged and resources are mobilized. A city is defined as a community with a large enough population and resource base to allow specialization in arts, crafts, services, and professions. An incorporated community is defined as a city when it has more than 2,500 residents as urban regardless of size. Beyond about 10 million inhabitants, an urban area is considered a supercity or a megacity, such as New York, Mexico City, Sao Paulo, and Tokyo.

At the beginning of the Industrial Revolution only 3% of the world population were living in cities. Now about 43% of the world's people live in cities. In the U.S about 79% of the population is urban.

In 1900, thirteen cities had populations over 1 million; all except Tokyo were in Europe or North America. Presently, only one of the ten largest cities (New York) is in North America or Europe. By 1990, there were 235 metropolitan areas of more than 1million people- an eighteen fold increase. In 1900, London was the only city with more than 5 million people; now nineteen cities have populations above 5 million.

Urban population grows in two ways: by natural increase (more births than deaths), and by immigration. Natural increase is fueled by improved food supplies, better sanitation, and advances in medical care that reduce death rates and cause populations to grow both within cities and in the rural areas around them. Immigration is the second reason why population grows, and it is the largest source of its growth. Immigration to cities can be caused both by push factors that force people out of the country and by pull factors that draw them into the city.

Immigration Push Factors - The "surplus" population is forced to migrate to cities in search for jobs, food, and housing. In some places, economic forces or political, racial, or religious conflicts drive people out of their homes. The UN estimated that in 1992 at least 10 million people fled their native country and that another 30 or 40 million were internal refugees within their own country, displaced by political, economic, or social instability.

Immigration Pull Factors - Even in the most chaotic cities, people are there by choice, attracted by the excitement, vitality, and opportunity to meet others like themselves. The most important thing to them is that cities offer jobs, housing, entertainment, and freedom from the constraints of village traditions. Possibilities exist in the city for upward social mobility, prestige, and power not available in the country.

Large cities in both developed and developing world face the same kind of problems, similar challenges in accommodating the needs and by products of dense population. The problems get bigger and bigger especially in the developing countries.

Traffic and Congestion - Every big city is often overwhelmed by the immense crush of pedestrians and vehicles of all sorts that clog the streets. The noise, congestion, and confusion of traffic make it seem suicidal to venture onto the street. Cairo, for instance, is one of the most densely populated cities in the world. Traffic is chaotic all the time. In Sao Paulo, Brazil, the government passed such law that only allows certain cars to circulate on the streets according to their plate number. Gigantic traffic jams occur day and night, and it is common for people to wait two hours to get to a specific place.

Noise - City noises come from many sources. The traffic is generally the most omnipresent noise. Cars, trucks, and buses create a roar that permeates nearly everywhere in the city. Near airports, jets thunder overhead, stopping conversation, rattling dishes, sometimes even cracking walls. Jackhammers rattle in the streets; sirens pierce the air; motorcycles, lawnmowers, snow blowers, and chain saws create an infernal din; and music from radios, TV's, and loudspeakers fill the air. It is known for a long time that prolonged exposure to noises, such as loud music or the roar of machinery can result in hearing loss. Today, noise is one of the biggest problems in large cities.

Air Pollution - The dense traffic (commonly old, poorly maintained vehicles), smoky factories, and use of wood or coal fries for cooking and heating often create a thick pall of air pollution in the world's supercities. Lenient pollution laws, corrupt officials, inadequate testing equipment, ignorance about the sources and effects of pollution, and lack of funds to correct dangerous situations usually exacerbate the problem. An estimated 60% of Calcutta's residents are thought to suffer from respiratory diseases linked to air pollution. Lung cancer mortality in Shanghai is reported to be four to seven times higher than rates in the countryside. Mexico City, which sits in a high mountain bowl with abundant sunshine, little rain, high traffic levels, and frequent air stagnation, has one of the highest levels of photochemical smog in the world.

Sewer Systems and Water Pollution - Few cities in developing countries can afford to build modern waste treatment systems for their rapidly growing populations. The World Bank estimates that only 35 percent of urban residents in developing counties have satisfactory sanitation services. The situation is especially desperate in Latin America, where only 2 percent of urban sewage receive any treatment. In Egypt, Cairo's sewer system was built about fifty years ago to serve a population of 2 million people. It is now being overwhelmed by more than 11 million people. Less than one-tenth of India's 3,000 towns and cities has even partial sewage systems and water treatment facilities. Some 150 million of India's urban residents lack access to sanitary sewer systems. In Colombia, the Bogotá River, 200 KM (125 miles) downstream from Bogotá's 5 million residents, still has an average fecal bacteria count of 7.3 million cells per liter, more than 700,000 times the safe drinking level and 3,500 times higher than the limit for swimming.

Crime - What can we do about crime and violence in the city? Clearly, we all would benefit if the stresses in urban environments caused by pollution, noise, litter, squalor, and congestion were reduced. We also should try to make decent housing, jobs, and education available to all. Perhaps we also need to find ways to divide the city into smaller neighborhoods, encourage diversity in population and housing, reduce the total population size and density, and provide opportunities for advancement and hope for the future so that people won't feel so alienated and angry. Crime in big cities are often related to religion, lack of education, unemployement, and bad financial situation. The problem is much worst in the Developing Nations whereas people sometimes steal and kill in order for food and clothing.

Transportation plays a very important role in a city. It is needed to bring building materials, energy source, food, etc. Automobiles brought many changes to cities. The middle class moved to single-family housing developments that filled in open spaces between transit lines.

The decision to build freeways has been called the most important land-use decision ever made in the U.S. Freeways have profoundly reshaped transportation in this country.

But freeways also brought problems. They have torn through neighborhoods, choked cities with traffic, and increased energy consumption, caused pollution, noise, and urban sprawl.

City planning has a long history. It started in the earliest cities of Mesopotamia and India, and it still exists today. Alexandria on the Nile delta in Egypt was a splendid examples of Greek city planning. It was beautifully situated, with an orderly, unified design, magnificent buildings, and a pleasant mix of public and private spaces.
These planned cities resembled efficient ecosystems in which inhabitants participate in exchange of matter and energy with their environment. Washington D.C. is one the most notable city plans in the United States. Washington's rectangular street grid is cut by diagonal avenues converging on the Capitol and Executive Mansion, forming numerous squares, circles, and triangles that make interesting spaces for pocket parks. The broad, tree-shaded streets and impressive vistas created by this plan make Washington a grand setting for the national capital.
	Brasilia, Brazil's capital, is another example of a planned city. Designed by Argentinean architect Oscar Niemeyer, Brasilia was built in the shape of an airplane, which makes it easy to access. The city is divided into four parts: nose, tail, north wing, and south wing.

The twentieth century has seen numerous experiments in building new towns for society at large that try to combine the best features of the rural village and the modern city. Garden cities are cities separated from the central city by a greenbelt of forests and fields. Howard was the first modern urban planner to advocate comprehensive land-use planning and to reintroduce the Greek concept of organic growth and human scale to the city. Business and industries were screened from housing areas by vegetation. Planned communities also have been built in the United States following the theories of Ebenezer Howard, but most plans have been based on personal automobiles rather than public transit. Towns such as Seaside in northern Florida and Laguna West near Sacramento cluster houses to save open space and create a sense of community. Commercial centers are located within a few minutes walk of most houses, and streets are designed to encourage pedestrians and to provide places to gather and visit.

An alternative to spreading the population across a wide area of countryside is to build upward. This model, which depends strongly on technology. They have been called the technopolis, vertical city, or city of the future. The central hub of most big American cities now is dominated by skyscrapers and a highly technological environment. The emerging supercities of the Developing World are also moving toward this style, in part because of its association with wealth, power, and progress.

Japan is now building eighteen new high-technology cities intended to be centers for economic and scientific growth in the next century. With names like Teletopoia, Agripolis, New Media City, these regional research, education, and marketing centers will have innovative housing, enclosed shopping malls, and high technology communication, and transportation systems. They will concentrate on leading-edge research and industries, such as fifth-generation supercomputers, biotechnology, lasers, ceramics, and bioelectronics. Some such high-tech cities may be giant and floating. Others may consist of a maze tunnels and chambers entirely underground, not unlike a giant ant nest, opening onto huge twenty-story-deep air wells. This plan would conserve energy and preserve scarce surface air; however, many technical and psychological problems need to be overcome.

Although suburbs have many advantages, they also have disadvantages. Most suburbs are too spread out for people to meet and interact. Residential streets are empty during much of the day. Suburbs often have no sense of community and can be places of alienation and loneliness, just as cities are sometimes. Although many urban problems have been eliminated, so have many of the finer aspects of city living. Suburbs, for instance, lack the activities, energy, and diversity that make cities more dynamic.

What can be done to create ideal suburban environments? Not everyone will want to leave established suburban communities for new garden communities or wilderness utopias. We need, instead, find ways to remodel and revitalize existing urban cities, reduce their problems, and adapt to the changing of their residents.

On a global scale, the most urgent challenge is to provide for the basic needs of the urban poor and thereby alleviate the toll of human misery associated with degraded urban environments. Throughout the cities of the developing world, meeting this challenge will entail activities ranging from providing fundamental urban services such as water and sanitation and garbage collection to reforming land tenure policies. Much is to be gained from encouraging income- generating activities, such as waste recycling, that simultaneously improve livelihoods and the local environment.

A second and related challenge for those cities is to develop strategies to reconcile economic growth with environmental protection. Some of the worst examples of environmental degradation can now be found in and around the rapidly industrializing cities of the developing world, where economic growth is proceeding without adequate concern for its environmental impact. These cities need to find ways to both encourage economic development and provide their citizens at least their basic needs.