Urbanization Models

The Central Business
District

◦ Definition:
CBD is compact, less
than 1% of urban land
area
◦ But contains a large % of
shops, offices, and public
institutions
◦ Consumer services and
business services are
attracted to the CBD
because of its accessibility
◦ High land costs
 Discourages Industry in
the CBD
 CBD- original core of a city’s
economy, like a nucleus of a
cell

Characteristics of a CBD
◦ Intensive land use
 Skyscrapers

All of the following
models possess a
central business district
◦ Degree of influence and
geographic location of
CBD varies throughout
different models
 Center is easiest part of city
to reach from the rest of the
region
◦ Focal point of region’s
transportation network
Comparative Models of North
American Cities

Concentric Zone Model

Also called the Burgess
model
◦ Developed in 1920’s by E.W.
Burgess
◦ 1st model to explain and predict
urban growth
 All other urban models are built
on this model

Based on urban growth in
Chicago

Model suggests that a city’s
land use can be viewed from
above as a series of
concentric rings
◦ As the city grows and expands,
new rings are added and older
rings change their function
◦ Size and shape of rings vary per
city
Comparative Models of North
American Cities

The five rings:
◦ 1- CBD
 innermost ring where nonresidential activities are
located
◦ 2- Zone of transition
 Contains industry and poorerquality housing
 Immigrants to city often 1st
live here
◦ 3- Zone of working-class
homes
 Modest, older homes
occupied by stable, workingclass families
◦ 4- Zone of better residences
 Contains newer and more
spacious houses for middleclass families
◦ 5- Commuter Zones
 Beyond the continuous builtup area of the city
Comparative Models of North
American Cities

The model assumes a
process sometimes called
invasion and succession
(or succession migration)
◦ Definition:
 New arrivals to cities 1st tend
to move to the inner rings
near the CBD
 This pushes the people and
economic activities already
present out into further rings


In model, the CBD is
the premiere land-use
ring nearest the point of
maximum accessibility
◦ Called peak land value
intersection
 Highest real estate prices
 Land values decrease as
you move away from CBD
◦ Furthest ring the cheapest
This constant pattern can
lead to a ring known as
the zone in transition
◦ Definition:
 Zone outside CBD
 Never really developed
◦ Developers know that it will be
constantly caught in shift
 Sometimes called “skidrow”
Concentric Zone Model

Bid-Rent curve predicts the
land prices and population
density decline as distance
from the CBD increases

Bid-rent curves show the
variations in rent different
users pay for land at
different distances from
some peak point of
accessibility and visibility
in the market
◦ Usually the CBD

Transportation costs
increase as you move away
from the market
◦ Rents usually decrease as
distance increases from the
market
Bid-Rent Curve

Different types of land
use generate different
bid-rent curve
◦ Ex: commercial retail,
industrial, agriculture,
housing

Bid-rent curves explain
the series of concentric
rings of land use found
in the concentric zone
model

Model shows a pattern
in which architectural
form and function of
buildings match in each
concentric ring and
urban land use
Bid-Rent Curve

Sector Model was
developed by Homer
Hoyt in 1939
◦ Discovered a twist on the
concentric zone pattern
 According to Hoyt, the city
develops in a series of
sectors, not rings
 Also based off of Chicago

Model grew out of
observations that there
were urban land-use
zones of growth based
on transportation routes
and linear features
◦ roads, canals, railroads,
major boulevards
◦ Not just concentric zones
around the CBD
Sector Land Use Model

The Sector Model
explained that similar
land uses and
socioeconomic groups
clumped together in
geometric sectors
 Certain areas of the city
are more attractive for
various activities
◦ Sectors radiated out
from CBD along
particular transportation
routes
 Ex:
◦ Many factories follow rail
lines, housing followed
public transportation,
visitor services along
major highways
Sector Land Use Model

New Model of urban growth
discovered in 1945
◦ Chauncy Harris and Edward
Ullman

Unlike previous models that
focused on a strong CBD, this
model suggested that growth
occurred independently
around several major focal
points
◦ A.K.A. a city is a complex
structure that includes more than
one center around which
activities revolve
 Ex: airports, universities,
highway interchanges, ports

Focal points may be distant
from “original” CBD and only
loosely connected
◦ Suggesting a reduced dominance
of the CBD
Multiple-Nuclei Land Use Model

The multiple nuclei model
reorganized that land use
zones often popped up at
one, in chunks
◦ Industrial parks, shopping
centers, and housing zones
could be built in one, giant
sweep of construction and
be only very loosely
connected to the original
heart of the city


Some activities are
attracted to particular
nodes, whereas other
try to avoid them
◦ Example:
 A university node might
attract pizza places and
bookstores
The model does not
suggest the CBD is not
necessarily unimportant
◦ but does show that new
areas of intense, urban
growth (called nuclei) can
grow simultaneously
around key nodes of access
or industry
Multiple-Nuclei Land Use Model


The three models help to
understand where people with
different social characteristics
tend to live within an urban
area
Can also help explain why
certain types of people live in
particular places
◦ Uses social area analysis
 Uses census information to
compare characteristics

None of the models
individually explain why
different types of people live
in distinctive parts of the city
◦ When combined, more helpful

Critics
◦ Models are too simple
◦ Fail to consider the variety of
reasons that lead people to
select particular residential
locations
◦ All three models created between
WWI/ WWII

The models say that most
people prefer to live near
others who have similar
characteristics
◦ Concentric Zone
 Consider two families with the
same income and ethnic
background
 One family owns a home, the
other rents
 The owner would more likely live
in an outer ring and the renter in
the inner ring
◦ Sector Model
 Given two families who own
homes, the family with the
higher income will not live in the
same sector of the city as the
family with the lower income
◦ Multiple Nuclei
 People with the same ethnic or
racial background are likely to
live near each other
 No longer relevant
Apply the Models

Developed by James Vance in 1960s
◦ Influenced by increasing importance
of automobile
◦ Explained suburban regions that were
functionally tied to mixed-use,
suburban downtowns with relative
independence from the CBD
 Developed while observing the San
Francisco Bay area metropolis

Model grew from the multiple-nuclei
model

Argued nuclei were not just focal
points of urban growth but
developing into functioning “urban
realms”

Urban realms model recognized that
many people’s daily lives and
activities occurred within a fixed
activity space within a portion , or
urban realm, of a larger metro
region
◦ In these “urban realms” on could find
suburban downtowns filled with
amenities needed for living
◦ “urban realms”
Urban Realms Urban Land Model

In the 1960’s, Samuel
Borchert studied cities in
the United States and
linked historical changes
to urban evolution
◦ Borchert’s model defined
four classical of cities
based on the
transportation technology
that dominated the era
when the city hit its initial
growth spurt and found it’s
comparative advantage

Classifications
◦ Stage 1
 Hit growth spurt in “sailwagon” era of 1730-1830
 Mostly near ports and
waterways for
transportation
◦ Stage 2
 “iron-horse” cities
 Grew around rivers and
canals between 1830-1870
when railroads and
steamboats were growing
rapidly
◦ Stage 3
 “steel-rail epoch”
 1870-1920
 During IR, when steel
industry blossomed
◦ Stage 4
 1920
 Linked to air and car travel
Borchert Model of Urban Evolution

In contrast to U.S. cities,
wealthy Europeans still live in
inner rings of the upper-class
sector
◦ Not just in the suburbs

As in the U.S. wealthier
Europeans cluster along a
sector extending out from the
CBD
◦ Often away from factories, on
higher elevations

Before electricity social
segregation was vertical
◦ Meaning poor people lived in the
basements or attics of buildings

Today lower income families
live outside the inner-city
◦ Mainly outskirts
European Cities

Latin American City
Structure Model
◦ Also called Ford-Griffin Model
 Created by Larry Ford and
Ernest Griffin
◦ Particularly focused on areas
colonized by Spain

Most medieval cities in
Europe were laid out in
unplanned jumbles
◦ 1400s- Renaissance saw
rebirth of Greco-Roman
architecture and planned
cities
◦ 1573- Spain passed a law
ordering all colonial cities be
built according to GrecoRoman designs
 Prominent, rectangular plazas
dominated by Catholic
Church and major
governmental buildings
Latin American Cities

Commercial and residential
zones encircled the Latin
American plaza
◦ Similar to CBD in North
American cities
◦ CBD was most important in
the focus of Latin America
 Suburbanization weaker


Other zones
 Zone of in situ accretion
◦ A region transitioning
towards maturity and
development that is a mix of
middle-income and lowerincome families
 Zone of maturity
◦ Includes services and
infrastructural development
In a Latin American city,
wealth typically decreases
as one moves outward
from the downtown area
◦ Typically squatter
settlements and rings of
poverty are found in rings
outside of the CBD
 Zones of squatter
settlements are called
Perifericos
Latin American City Structure Model