THE URBAN SYSTEM

CENTRAL PLACE THEORY and RELATED CONCEPTS

The US at night

Is there an order to this?

Maybe it’s an underlying geometry in the settlement pattern…

Is there an order to this?

Maybe all we need to do is rearrange the cities slightly to make the pattern apparent.

OBJECTIVE to understand the dynamics shaping

the urban hierarchy what makes cities grow quickly or slowly? how do urban settlements of a particular

size affect the emergence and growth of other settlements of the same or different size?

what pattern would the system of settlements form in the absence of complicating factors such as topography and history?

Why ask these questions? to advance toward a more scientific

understanding of urbanization to develop a foundation on which to build

a positivist theory of urban growth to “raise” urban studies to the “level” of

the hard sciences--assuming the hard sciences are superior to the soft (humanistic, descriptive, probabilistic) sciences

Every science needs a force … economic competition

between cities rational maximization

by individuals friction of distance as a driving

force cost distance time distance (later) cognitive distance

In short… Through rationally maximizing the

productivity of their time… by minimizing the costs of various activities

measured in money and time, people collectively create a system in which

facilities of all sorts… including cities,

are pitted against each other… and all facilities emerge from this

competition in advantageous locations and with predictable-sized areas of dominance.

Competition Produces Order

In other words …

Founders of Central Place Theory

C.J. Galpin (1915) sociologist studying rural communities in

Wisconsin decided that under ideal conditions

settlements would be spaced evenly pattern: overlapping circular service areas

with the central places aligned in a hexagonal array

overlap of service areas indicates a region in which a person is equally inclined to shop at either central place

Galpin’s model

Founders of Central Place Theory

Walter Christaller (1966) assumption: each good has its

particular range and threshold

threshold of a good: minimum size of market capable of sustaining a business devoted to that good

range of a good: maximum distance a person will be willing to travel to obtain that good

associated assumptions variations in range and

threshold from person to person or from culture group to culture group are irrelevant

most people will shop at only one center

Details of Christaller’s theory The vast range of retail functions could be

grouped into 7 “orders,” corresponding to cities with different sized hinterlands

the functions in an order share a similar threshold and range

automobiles would be in a different order than loaves of bread, for example

What might be in the same order as automobiles?

What might be in the same order as loaves of bread?

Hypothetical pattern of central places

More terminology “Higher order” goods and services are those

with a wider range and higher threshold, located in larger urban centers

“Lower order” goods and services are those with a narrower range and lower threshold, located in smaller urban centers

“break point”: the invisible boundary between markets of competing central places

“isotropic plain” uniform land surface on which these ordering principles would generate a hexagonal pattern of cities

An interpretation of the urban hierarchy (listed by order)

1. largest cities (all functions, highest to lowest)

2. large cities 3. small cities 4. larger towns 5. smaller towns 6. villages 7. hamlets (only the lowest order functions)

Variations on the basic theory different patterns result from different values

of k market optimizing, k=3 (minimizes total

number of settlements serving a region) traffic optimizing, k=4 (emerges by

minimizing the road lengths joining all adjacent centers)

administration optimizing, k=7 (assumes lower-order places must be contained in the administrative districts of higher order places; can not be situated on the breakpoint)

Market principle (a) and transportation principle (b)

Market principle

Transport principle

Administrative principle

The US at night

Cool idea, not much basis in reality cities just don’t form these patterns they do respond to some kind of

hierarchy-forming process, however

evidence: the rank-size distribution

alternative explanation: connection rather than competition: the

power function law of networks

settlement order & predicted frequency

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marketing principle

transport principle

administrative principle

Founders of Central Place Theory

August Lösch (1954) similar to Christaller’s theory but

without the classification of urban functions into a finite number of orders

implication was that cities could be any size and would form a continuous distribution of sizes

Power laws and scale-free networks

Recent research on networks of various types (Internet, neural networks, social networks, electrical grid, ecological systems, biochemicals, brains) has revealed that the hierarchy of node degree consistently follows a power law relationship: straight line on a log-log graph.

What would this indicate?

Urban hierarchy’s regularity may not be caused by the random perturbation of what would ideally be a step-wise function caused by competition between cities

Instead, it may be caused by the natural emergence of dominant (hub) nodes within a dynamic network