concentric zone model, sector model and multiple nuclei model

Concentric Zone Model

The Concentric Zone model is a model of the internal structure of cities in which social groups are spatially arranged in a series of rings. The Concentric Zone model was the first to explain the distribution of different social groups within urban areas. It was originally based off Chicago (although the model does not apply well to Chicago today). The model was created in 1923 by E.W. Burgess, Robert Park, and Roderick McKenzie. The idea behind this model is that the city grows outward from a central area in a series of rings. The size of the rings may vary, but the order always remains the same. This model suggests that the social structure extends outwards from the central business district, meaning that the lower classes live closer to the city center, while the upper classes live farther from the city center because they can afford the commute. Also, as you get further away from the city density decreases. The rent tends to increase as you get further away from the CBD and residents are more likely to rent near the center. As you get further away from the CBD it is more likely that you will find condominiums. Indianapolis is a city that can be applied to the concentric zone model today. That is because more people rent near the CBD than away from it. However, this model has its weaknesses. It does not take into account any physical barriers and it does not take into account gentrification- which may occur in these cities.

An important feature of this model is the positive correlation of socio-economic statuts of households with distance from the CBD — more affluent households were observed to live at greater distances from the central city. Burgess described the changing spatial patterns of residential areas as a process of "invasion" and "succession". As the city grew and developed over time, the CBD would exert pressure on the zone immediately surrounding it (the zone of transition). Outward expansion of the CBD would invade nearby residential neighborhoods causing them to expand outward. The process was thought to continue with each successive neighborhood moving further from the CBD. He suggested that inner-city housing was largely occupied by immigrants and households with low socio-economic status. As the city grew and the CBD expanded outward, lower status residents moved to adjacent neighborhoods, and more affluent residents moved further from the CBD.

Burgess's work is based on the bid rent curve. This states that the concentric circles are based on the amount that people will pay for the land. This value is based on the profits that are obtainable from maintaining a business on that land. The center of the town will have the highest number of customers so it is profitable for retail activities. Manufacturing will pay slightly less for the land as they are only interested in the accessibility for workers, 'goods in' and 'goods out'. Residential land use will take the surrounding land.

Problems with the Concentric Zone Model

The model has been challenged by many contemporary urban geographers. Firstly, the model does not work well with cities outside the United States, in particular with those developed under different historical contexts. Even in the United States, because of changes such as advancement in transportation and information technology and transformation in global economy, cities are no longer organized with clear "zones" (see: Los Angeles School of Urban Analysis).
• It assumes an isotropic plain - an even, unchanging landscape. Physical features
can interrupt the cycle
• Assumes transportation is the same everywhere and does not take into account better methods of
transportation
• It is based primarily on residences
• Assumes cities develop and are based on industry
• Assumes the condition of the land is the same everywhere
• Commuter villages defy the theory, being in the commuter zone but located far from the city
• Decentralization of shops, manufacturing industry, and entertainment in modern times thanks to
modern transportation systems
• Urban regeneration and gentrification - more expensive property can be found in 'low class'
housing areas
• Many new housing estates were built on the edges of cities in Britain
• It does not address local urban politics and forces of globalization
• The model does not work well for cities which are essentially federations of similar sized
towns, for example Stoke-on-Trent

The Different Rings of the Concentric Zone Model

1) Central Business District (CBD)- This area of the city is a non-residential area and it’s where businesses are. This area is called downtown in the U.S. and city center in Europe. This area has a developed transportation system to accommodate commuters coming into the CBD. Also, due to the high land cost in this area, a lot of sky scrapers are built in order to take full advantage of that land. Most government institutions, businesses, stadiums, and restaurants chose this area to build on due to its accessibility.
2) Zone of Transition- the zone of transition contains industry and has poorer-quality housing available. Immigrants, as well as single individuals, tend to live in this area in small dwelling units, frequently created by subdividing larger houses into apartments. Most people in this area rent.
3) Zone of the working class- This area contains modest older houses occupied by stable, working class families. A large percentage of the people in this area rent.
4) Zone of better residence- This zone contains newer and more spacious houses. Mostly families in the middle-class live in this zone. There are a lot of condominiums in this area and residents are less likely to rent.
5) Commuter’s Zone- This area is located beyond the build-up area of the city. Mostly upper class residents live in this area. This area is also known as the suburbs in the United States.

• Transportation costs and land costs are a big part of this theory (bid-rent curves)

sector model

Sector model- a model of the internal structure of cities in which social groups are arranged around a series of sectors, or wedges radiating out from the central business district (CBD) and centered on major transportation lines.

• Also known as the Hoyt Model. Developed in 1939 by land economist Homer Hoyt.
• He said that a city develops in a series of sectors, not rings.
• Different areas attract different activities by chance or by environmental factors.
• As the city grows, activities within it grow outward in a wedge shape from the CBD.

CBD- central business district, the area of a city where retail and office activities are clustered. It is also called the central activities district. In North America, it is called “downtown.” In Chicago, it would be the area closest to the lake, most notably Michigan Avenue.

Industry

• Industry follows rivers, canals, railroads, or roads
• Lower class workers work here. Paid little, bad working conditions.
• Produces goods or other domestic products for city

Low Class Residential
• Low income housing
• Near railroads that feed factories or
• Inhabitants tend to work in factories
• Live near industry to reduce transportation costs
• Pollution or poor environmental conditions due to industry (traffic, noise and pollution make it cheap)

Middle Class Residential
• More desirable area because it is further from industry and pollution
• Access to transportation lines for working people who work in the CBD, making transport easier
• Largest residential area

High Class Residential
• Housing on outermost edge
• Furthest away from industry
• Quiet, clean, less traffic
• Corridor or spine extending from CBD to edge has best housing.

Where it does and doesn’t apply (some weaknesses)
• Applies well to Chicago
• Low cost housing is near industry and transportation proving Hoyt’s model
• Theory based on 20th century and does not take into account cars which make commerce easier
• With cars, people can live anywhere and further from the city and still travel to the CBD using their car. Not only do high-class residents have cars, but also middle and lower class people may have cars.

BACKGROUND INFO
-theory of urban structure
-also known as Hoyt Model
-developed in 1939 by Homer Hoyt
-states that a city develops in sectors, not rings
-certain areas are more attractive for different activities because of an environmental factor or by mere chance.
-Hoyt modified the concentric zone model to account for major transportation routes
-according to this model most major cities evolved around the nexus of several important transport facilities such as railroads, sea ports, and trolly lines that eminated from the city's center.
-Hoyt theorized that cities would tend to grow in wedge-shaped patterns, or sectors, eminating from the CBD and centered on major transportation routes.
-It is a monocentric representation of urban areas
-He posited a CBD around which other land uses cluster
-But important factor is not distance from CBD as in the concentric zone model, but direction away from CBD
-As growth occurs, similar activities
stay in the same area and extend outwards
-The Hoyt model realized that transportation (in particular) and access to resources caused a disruption of the Burgess model.
-For example a rail line or major highway to a nearby city may result in business development to preferentially develop parallel to the rail line or major highway. So one side of a city may be completely industrial with another sector may be completely rural.

DEFINITION
-a model of the internal structure of cities in which social groups are arranged around a series of sectors, radiating from the CBD (central business district)

CBD
-the area of the city where retail and office activities are clustered
-commercial and geographic heart of the city
-ex: downtown in North America

LOW-CLASS RESIDENTIAL
-tend to be near railroad lines, and commercial establishments along the business areas
-have various transportation sources into an urban area or CBD. Some are railroads, tram lines, and seaports.
-close to industry to save commuting costs
-Lower-class people tend to work in factories more than businesses with offices
-borders manufacturing/industrial sectors (traffic, noise, and pollution makes these areas the least desirable)
-Aka- low income households

MIDDLE-CLASS RESIDENTIAL
-further away from manufacturing and industrial sectors making it more desirable than low-class residential
-connected with CBD for working middle class people to easily get to work
-the largest population in the city because the average working person can afford the housing

HIGH- CLASS RESIDENTIAL
-most expensive housing is built on the outer edge, further out from the center
-the best housing is found in a corridor extending from the downtown CBD to the outer edge of the city
-furthest away from manufacturing/ industrial sectors making the environment around high-class residential to be quiet, have less traffic, and cleaner air.

INDUSTRY
-factories tend to go along rivers, canals, rail lines, or roads
-provide the needs for the people in the city
-consists of many lower class workers so that they can pay for many of them with the smallest amount possible

EXAMPLE-Chicago
-the upper class residential sector evolved outward along the desirable Lake Michigan shoreline north of the central business district, while industry extended southward in sectors that followed railroad lines.(Wikipedia)
-Hoyt argued that the best housing in Chicago developed north from the CBD along Lake Michigan, whereas industry located along major rail lines and roads to the south, southwest, and northwest. (book)

Multiple-Nuclei Model

Definition:

* Multiple-Nuclei model is a model of urban land use in which a city grows from several independent points rather than from one central business district. Each point acts as a growth center from a particular kind of land use, such as industry, retail, or high-quality housing. As these expand, they merge to form a single urban area. The CBD is not the only generator of change.
* Some centers or nodes include:
o ports,
o universities,
o airports,
o parks,
o neighborhood business centers.

This model, unlike others, takes into account the varied factors of decentralization in the structure of the North American city.

The multiple-nuclei theory was formed based on the idea that people have greater movement due to increased car ownership. This increase of movement allows for the specialization of regional centers (eg. heavy industry, business park). A term for the specialization of regional centers would a node. There is no clear CBD in this type of model.

The distant decay theory is still applicable to this model. Land value and population density decline with distance from the central places.

Difference among Concentric, Sector and Multiple nuclei models

1. monocentric – concentric, sector model; polycentric – multiple nuclei
2. multiple nuclei more complex in term of land use zones, e.g. industrial suburbs
3. multiple nuclei allows the suburbanization, transport development, outward growth of city
4. multiple nuclei model gives the idea of land use pattern of a city only

Criticisms about the Multiple nuclei model

1) Negligence of height of buildings.
2) Non-existence of abrupt divisions between zones.
3) Each zone displays a significant degree of internal heterogeneity and not homogeneity.
4) Unawareness of inertia forces.
5) No consideration of influence of physical relief and government policy.
6) The concepts may not be totally applicable to oriental cities with different cultural, economic and political backgrounds.