What are towns and cities

1
What are towns and cities?

• A town simply means a small settlement of people.
  Back one or two centuries ago such a place might
  only have a few hundred people.
• Cities are higher density concentrations of
  people and account for an increasing amount of
  people in the world.

2
This is obviously just a town

• It is a gathering of quite a few residences and
  businesses. But its not a heavy concentration.

3
This is definitely a city

• London to be precise.

4
A city cannot even be defined simply as a
settlement above a certain population size, nor
is there a definite threshold differentiating a
town from a cityWhich of these are cities and
which are towns?
5
urban areas are classified differently at
different times and in different places

• villages in southern Italy may have 8000-10000
  inhabitants
• Towns in Iceland may have only 300 people
• A settlement of 2000 in Africa may be considered
  a town.

6
Elements necessary to define cities

• A city to some extent refers to its physical
  characteristics buildings, roads and other
  elements of infrastructure and the people who
  live in it and the businesses and organizations
  that operate within it.
• But we also recognize cities by their size, the
  physical are of the city, the size of its
  population and most importantly the functions it
  carries out. The term city refers to both form
  and process
• What matters most are the degree to which urban
  functions or tertiary activities are carried
  out

7
Central place theory

• Provides
• Insight into the urban structure
• Locational patterns of retail and services
• Relationships between markets and consumers
• Relationships between places

8
Locational Patterns of Cities

• Cities are normally
• Transport centers
• Provide means physical requirements and services
  for transportation and a place to change modes of
  transport
• Typically aligned along major transport routes
• Found at junctions of diff/ transport modes
• Rivers and coastal locations
• Centers of specialized functions
• Centers are sometimes dominated by one function
• Agglomeration of activity, clustering
• Examples include Pittsburgh and Orlando
• Central places
• Centers for exchanging goods or services
• Provides retail, wholesale, financial,
  educational, govt. services

9
Cities and Trade

• 3 types of services/trade
• Trade which helps create central places
• Business conducted totally w/i the city and its
  hinterland
• Reliance on population and size of center
• Trade that contributes to growth of a central
  place
• Activities conducted outside the hinterland
  (national level)
• No reliance on population and size of center
• Trade which must exist to service the central
  place
• Internal business such as the sale of goods and
  services to its residents
• Reliance on population and size of center

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Service Areas

• Cities service areas larger than themselves
• Hinterlands
• Areas surrounding the city but far from it with
  few direct ties.
• Tributary areas
• source of materials and labor supply
• Market areas
• area surrounding central places that includes
  potential customers for whom price and transport
  cost can be justified
• Urban fields
• source of materials and labor supply

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Central Place Theory

• Addresses 4 questions
• How many central places will develop?
• Why are some central places larger than others?
• Where will the central places develop?
• What will the size of the market area be?

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Walter Christallers Central Place

• German geographic, 1930s
• examined the data on central places to see how
  distance from one another, urban function, and
  location were related. He used this as a basis
  to develop his theory.
• Theory basics
• Primary function is providing goods and services
  for a surrounding market
• Greater numbers of good and services provided
  equates to a higher order of place
• Low order places offer convenience goods w/i a
  small market area
• High order places are few in number, providing
  goods with a greater range
• There is a hierarchy of central places that makes
  the arrangement of these goods efficient

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Christaller

• 3 major principles found in the most efficient
  systems of central places
• Marketing principle equal access, central places
  located at midpoints
• Transportation principle maximizing connectivity
  while minimizing network length
• Administration principle primary market has
  several dependent markets

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Relationships Between Central Places

• The larger the central place, the greater the
  distance to an equivalent center
• The larger the central place, the more variety of
  services
• Central places similar in size offer a similar
  set of services
• Higher levels of central places, less of them

15
An Analogy

• A central place is like a planetary system in
  which the units are held in in place by the
  gravitational forces between them. Thus central
  place theory purports to show that each
  particular urban settlement is, so to speak, held
  in place within a system of cities, it suggests
  that the development of each is affected in a
  predictable way by its position within the
  system." (James Heilbrun 1989).

16
Basic Theory Assumptions

• Isotropic surface (uniform costs)
• Uniform distribution of demand and population
• No transport barriers
• Dependent on trade with hinterland
• Producers and consumers are optimized
• No social class or govt. intervention/regulation
• Ubiquitous production inputs _at_ same price
• No shopping externalities
• Linear market with evenly spaced consumers

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Building the theory

• Many small farmers spread equidistantly across
  the plain.
• Each develops a comparative advantage and
  therefore a specialty in a given product
• Each has a monopoly over some circular market area

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Monopoly profits induce more producers
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Eventually they begin to crowd into each other.

• To cover the whole service area and not leave an
  area unserved, the range circles must overlap.
  But consumers can only shop in one place in this
  theory!

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What is the spatial solution?

• Answer hexagons (six-sided shapes) that
  completely cover an area without overlap or
  unserved areas.

21
Additional Concepts

• Threshold (inner range) of a good
• minimum level of demand that will allow a
  business to operate and break even
• Range of a good
• max distance that people are willing to travel
  for a good
• Different goods have different ranges and
  thresholds
• Low order goods frequently purchased
• High order goods infrequently purchased
• Also applies to places low order vs. high order

22
Range and Threshold

• Normally, the threshold is found within the
  range, as the diagram shows. Can you think of
  examples from the past in Europe and from the
  United States today in which the range is larger
  than the threshold yet businesses thrive and
  market towns temporarily come alive?

23
Range and Threshold

• Because different products and services have
  different ranges and thresholds, there is a
  hierarchy of central places
• Each level of the hierarchy is characterized by
  a different number of goods and services that are
  offered
• The central place and its place in the hierarchy
  depends on how many market areas (for different
  products and services happen to coincide at that
  place. 

24
Range and Threshold

• High-order goods are available only at a few
  locations      They are expensive and purchased
  infrequently      They have a high threshold and
  wide ranges
• Low order goods provided by a large number of
  locations      They are relatively cheap and
  purchased frequently

25
Range and Threshold

• What happens if range is less than threshold?
•     - Producer will not be able to stay in
  business     - Periodic markets in developing
  countries (arts festivals, swap meets) is the
  context where range is less than threshold

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Details of Central Place Theory

• Christaller noted three different arrangements of
  central places
• The marketing principle (K3 system)
• The transportation principle (K4 system)
• The administrative principle (K7 system).
• Christaller found that the number of settlements
  at any level in either of these hierarchies is
  directly related to which hierarchy it is.

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K 3

• Provides for the largest provision of goods and
  services from the minimum number of central
  places
• this type of hierarchy prevails where it is most
  important for society to ensure equal provision
  of goods and services
• Each higher order CP is surrounded by six places
  of the next lowest order Market area of the
  higher order center is 3 times as large as that
  of the smaller center
• In the K3 network smaller centers are not
  accessible to the highway network connecting
  higher order centers  

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K3 System
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K 4
The market principle predicts evenly spaced
cities but the transportation and political
principles modify these regularities. With the
transportation principle, towns not on major
transportation routes are smaller than expected
from the market principle.
Tranportation routes, such as a railroad in this
illustration, attract business and allow more and
larger towns to develop along the railroad.
Rivers, canals, and highways also reflect the
transportation principle.
30
K4 System
Transportation Line
31
K 4
Lower order centers are located at midpoint of
each side of the hexagonal trade area rather than
the corners (as in K3) By shifting lower order
centers to a point midway between each higher
order center, highway network provides better
accessibility As many places as possible lie on
direct traffic routes between more important
centers
32
K 7
Central place network depends on political
boundaries Centers that are shared pose problems
Any pattern of control that cuts through
functional units is problematic K7 seeks an
arrangement where lower order centers are
entirely within a higher order center Results in
a more economically and politically stable
arrangement of settlements Each center controls
six dependent centers Hinterlands are larger
than in K3 or K4 systems
33
K 7 System
34
K 7
Political principle. Political boundaries also
"distort" the even spacing of cities.Why is the
city on the Nevada side of the Nevada-Utah border
larger?
Answer the city on the Nevada-Utah border is
larger because all of the gambling business from
Utah can only be met in Nevada and gamblers want
to drive the shortest distance to gamble, which
in Nevada is the border city, not the interior
city
35
Applications
The cities need the export dollars' provided by
people in small towns, and the small towns need
the specialized services provided by the cities.
A strategy which helps both of them develop--in
which state level development resources are
shared can be analyzed thru CPT.  
36
Applications
CPT does a good job of describing the location of
trade and service activity. It also does a good
job of describing consumer market oriented
manufacturing. Small-town community economic
developers can secure quite specific, relevant
information about what kind of trade or service
enterprise will likely work, and what kind of
enterprise will not likely work in a given small
community.
37
August Losch

• Refined central place theory
• Lowest order places upward (reverse of
  Christaller)
• Assumptions
• Isotropic, homogeneous plain
• Dispersed pattern of activity
• Equal demand among activities
• Economic raw materials equally distributed
• How can economic differences develop?

38
Losch

• Surplus in production of consumer goods
• Transport costs limit the potential market
• Consumption declines with increases in price

39
Central Place Applications

• diffusion of innovations
• Attempts to demonstrate the diffusion of and idea
  or behavior geographically
• Diffusion based on size of town distance to
  central places
• Creates a probability surface to predict the
  diffusion
• the integration of urban places into the national
  urban system

40
Spatial Competition

• Classic central place theory does not acknowledge
  the idea of competing centers
• Assumption that consumers traveled to nearest
  center
• Consumers are indifferent to minute changes in
  price or quality
• Large changes will however cause a reaction
• Idea of overlapping and competing markets

41
Retail Location

• While Central place theory can be used to explain
  retail activity in urban areas, there are
• Complications
• No longer an isotropic plain
• Population varies
• Density varies
• Income structure
• Tranportation infrastructure more important

42
Configurations explaining urban development with
retail activity

• Ribbon development
• Specialized functional areas
• Hierarchy of business centers

43
Ribbon Development

• oriented to highway traffic
• Fast food stops, convenience stops
• Major arteries

I central business district
II fast food, convience stops etc
III - residences
IV secondary centers with gas station etc.
bus line
Highway
IV
II
I
III
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Specialized functional areas
Road / transit linkage
Rail linkage
Maritime linkage
Air linkage
Industrial parksAuto rowsMedical
centersComparative shopping, specialized
servicesNodes, Linkages and Urban Form
Built area
Accessibility node
Economic node
45
Hierarchy of business centers

Regional centers, community centers,
neighborhood centers
Region
Major center
Major transport axis
Secondary center
Neighborhood
46
A combination of all three can be see in the
evolution of a typical city that has been around
since the 1800s
Built up area prior to introduction of mechanical
transport Development consequent on steam
railways (specialized functions) Development
consequent on tramways (hierachical business
centers) Development consequent on motor buses
(ribbon development) Development consequent on
private car ( specialized functions)