Classic+Urban+Models

Classic Urban Models

The most popular models used to explain North American cities are the //Concentric Zone Model//, the //Sector Model//, and the //Multiple Nuclei Model//.

Concentric Zone Model

The Concentric Zone Model, also known as the Burgess Model, named after its creator, Ernest Burgess, was one of the first models made to show the structure of a common city. Now, the Concentric Zone Model cannot be applied to modern North American cities because of its simplicity; the model was created by Burgess in 1924 based on Chicago, Illinois' structure. Burgess used the bid-rent theory to create his model, the theory that explains that the farther away a piece of land is from the city, the less desired and cheaper it is. The CZM uses rings to separate the different areas of a city. It is often noted as the urban version of Von Thunen's Land Use Model, created a century earlier (see Agriculture Models).

The center of the CZM is the Central Business District, the main center of the city, the center of trade, commerce, culture, and politics. The first ring is the "factory zone," just outside the CBD. This ring holds most of the industrial areas in the city, and in more industrialized cities, holds most of the jobs. The second ring is the "zone of transition;" it holds most of the mixed residential areas and commercial areas (i.e. retail) The third ring is the "working class zone," where the workers of the city live (inner suburbs). Now the "working class zone" is known as the inner city because of the expansion of urbanization. The fourth ring in the CZM is the "residential zone;" this contains the nicer residential homes, mostly for middle-class workers. The final ring of the model is the "commuters zone" which holds the nicest homes of the upper-class, who are willing to travel from their ring to the CBD to work and shop.



Criticisms: - It does not work well for cities outside of the United States. - Because of advances in transportation and information technology, the model is not valid at times because cities are no longer separated into clear zones. - It describes peculiar American geography, where the inner city is poor and the suburbs are wealthy; the opposite is normal everywhere else. - It assumes an uneven, unchanging landscape. - The model does not account for physical features where creating some zones would be improbable or undesirable. - It does not address local urban politics and forces of globalization.

The Concentric Zone Model may not be able to be used in modern times, but it is still considered the start of modelling urban areas, and shows the progress our world has made to today's cities.

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Sector Model

In the late 1930s, Homer Hoyt created his Sector Model, partly because of the restrictions of the Concentric Zone Model. Hoyt focused on the residential patterns (basically what/why people lived where) and believed that the city grew out of the center of the city; because of this belief, he designed a model that had zones starting at the center of the city and extended to the edge of the city, like pie pieces. These pie pieces were drawn along avenues of transportation (railways, boulevards, highways, rivers, etc.) to make travelling in and out of the city easier. Unlike the Concentric Zone Model, the Sector Model allows for outward growth in any of the zones of a city.

At the center of the model is the CBD, where each zone had a "piece." One piece of the model is the "industrial zone," home to factories and major companies that give work to many living within the city. Next to the "industrial zone" is the "transportation zone" which is pretty self-explanatory :) On the outside of the "industrial zone" and the "transportation zone" are two "low-rent residential" zones. Hoyt theorized that because of the open access to public transportation and abundance of industrial jobs, the less-wealthy and less-skilled would most likely live around those two zones. On the outside of the two "low-rent residential" zones are two "intermediate-rent residential" zones. These people need more access to the city and less to the "industrial zone" because they are typically better-educated, giving them better jobs. Inside the two "intermediate-rent residential" zones are the "high-rent residential" zone and the "education and recreation" zone; these people plus the "intermediate-rent residential" people live around the "education and recreation" zone because they can better afford it, and therefore must be closer to that zone.



Criticisms: - The model is based on 20th century railroad transport, and does not account for private cars enabling people to travel to the city from cheaper land outside the limits. - It does not account for physical features where creating some zones would be improbable or undesirable. - The growth of a sector can be limited by suburb and exurb land use (having to "jump" over the -urbs to continue the sector)

The Sector Model made farther strides than the Concentric Zone Model, but it still had its limitations; yet, the Sector Model can be applied to some modern cities today.

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Multiple Nuclei Model

The Multiple Nuclei Model was created by Chauncy Harris and Edward Ullman because of their belief that neither the Concentric Zone Model nor the Sector Model correctly reflected the organization of a city. Their model suggested that the CBD was losing its dominant position as the only focus of urbanization in the city. Instead of focusing on rings and residential areas, Harris and Ullman focused on grouping zones together that fit (i.e. hotels and rental car places are near airports) and co-dependently helped one another's business. Another large component of their model was the fact that people owned cars, and they were going to be driven; therefore the city was larger and the regional urban centers could be more specialized.

The Multiple Nuclei Model can have numerous urban centers and does not fit to one model because every city is different in size and needs and specialty.

Not in the center, but positioned wherever best fit, is the CBD, seen still as a center for business, but not necessarily the only one, and helped with transporting from one zone to another. Just outside the CBD is the "low-class residential" zones, where lower class people live, for property prices plus the access to certain zones helpful to them. In the center of the "low-class residential" zones is the "wholesale, light manufacturing" zone, where some businesses with no heavy-duty factories can go and supply jobs to the lower class residents. On the outside of the "low-class residential" zones is the "heavy manufacturing" zone, where bigger companies can go and be away from people they could pollute, but still have the lower class labor pool available. On the outskirts of the city, outside the "heavy manufacturing" zone, is the "industrial suburb," where people working in the "heavy manufacturing" businesses have the ease of being close to work. On the opposite side of the CBD, is the "middle-class residential" zone, where the middle class can live and have an easy time getting back and forth from the city. On the outside of the "middle-class residential" zone is the "high-class residential" zone where those of wealthier status can live. In between the "middle-class residential" and the "high-class residential" zones is the "outlying business district" where businesses of not-industrial type can prosper with the job pool of the middle and upper class. On the outside of the "high-class residential" zone is the "residential suburb" zone where more people working in the "outlying business district" can live, with the access to work.

The Multiple Nuclei Model is most widely accepted as a modern model, and has almost no criticisms. Many believe this model is the best representation of a modern city and is most used as a description of a North American city.

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=Citations for Pictures=

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 * http://advancedprocrastinators.com/aphg/images/burgess.gif
 * [|http://][|www.geography.learnontheinternet.co.uk/images/urban/hoyt.gif]
 * http://cronodon.com/sitebuilder/images/Harris_Ullman-533x690.jpg