The document discusses urban systems, highlighting the interdependence of towns and cities within a national context and the classification of urban systems based on openness and interdependence. It explores central place theory, detailing economic behaviors related to the distribution of goods and services, and critiques the assumptions underpinning these theories. The content also includes the diffusion of settlements and theorizes about the evolution of urban centers, ultimately emphasizing the complexity and variability of settlement patterns.

1. ESG-4102: Urban Geography and Planning
Lecture 03: Urban Systems
A H M Nahid
Assistant Professor
Department of Development Studies
Islamic University, Kushtia
Lecture by A H M Nahid

2. Urban Systems
• At the national level, cities are part of a complex system of
interrelated urban places, and are key elements in the economic,
social and political organization of regions and nations.
• The interdependence among towns and cities makes it important to
view a country as a system of urban places rather than as a series of
independent settlements.
• The concept of an urban system refers to a set of towns and cities
that are linked together in such a way that any major change in the
population, economic vitality, employment or service provision of
one will have repercussions for other places.

3. Urban systems at the intra-national scale
• From the eighteenth century onwards the urban structure of Western nations became
more complex. Traditional cities became more functionally integrated into regional and
national urban systems, while larger cities expanded and developed their economic and
social systems.
• Three levels of urban system may be identified in Western industrial countries:
1. A national system dominated by metropolitan centers and characterized by a step
like population-size hierarchy, with the number of places at each level increasing in a regular
manner with decreasing size of place.
2. Nested within the national system are regional subsystems of cities, displaying a
similar but less clearly differentiated arrangement, usually organized around a single
metropolitan center.
3. Contained within regional subsystems are local subsystems or daily urban systems
representing the life space of urban residents.

4. Classification of National City Systems
• Pred (1977) has suggested a fourfold classification of national city
systems based on their degree of openness/ closure and level of
internal interdependence:

5. Types of Places in the NUS

6. US City Types (by Logan and Molotch, 1987)
Types Example Key Functions
Headquarters New York City NY; Los Angeles CA Corporate centers: dominance in cultural production, transport and communication
networks; corporate control and coordinating functions of many large transnational
corporations and international banks
Innovation
centers
Silicon Valley towns, including Santa Clara CA;
Austin TX; and Research Triangle NC
Research and development of aerospace, electronics and instruments; some are (or
were) so involved in military contracting that they are ‘war preparation centers’
Module Production
Places
Alameda CA (military base); Hanford WA
(nuclear waste); Omaha NE (the ‘800’ phone
exchange center); Detroit and Flint MI (cars)
Sites for routine economic tasks (e.g. assembly of autos, processing of magazine
subscriptions or credit card bills), some located near a natural resource (e.g. mining
center) or government function (e.g. Social Security main office in Baltimore MD)
Third World entrepôts
(warehouses)
Border cities such as San Diego CA; Tijuana,
Mexico; Miami FL
Trade and financial centers for importing, marketing and distributing imported goods,
including illegal goods such as drugs and pirated music; major labor centers because
of their large numbers of low-paid workers in sweatshop manufacturing and tourist-
oriented jobs such as hotel maids
Retirement
Centers
Tampa FL; Sun City AZ Home to growing numbers of ageing Americans. Range: affluent towns that maximize
services to less affluent cities dependent on pensions, social security and other public
programmes to support the local economy
Leisure-tourist
Playgrounds
Tahoe City CA; Las Vegas NV; Atlantic City NJ;
Disney World FL; Williamsburg VA
Range: theme parks, sport resorts, spas to gambling meccas, historical places, and
cultural capitals

7. Central Place Theory

8. Assumptions
1. There is an unbounded uniform plain in which there is equal ease of transport in all directions. Transport
costs are proportional to distance and there is only one type of transport.
2. Population is evenly distributed over the plain.
3. Central places are located on the plain to provide their hinterlands with goods, services and
administrative functions.
4. Consumers minimize the distance to be travelled by visiting the nearest central place that provides the
function that they demand.
5. The suppliers of these functions act as economically rational human beings, that is, they attempt to
maximize their profits by locating on the plain to obtain the largest possible market. Since people visit the
nearest center, suppliers will locate as far away from one another as possible so as to maximize their
market areas.
6. They will do so only to the extent that no one on the plain is farther from a function than he or she is
prepared to travel to obtain it. Central places offering many functions are called higher-order centers;
others, providing fewer functions, are lower-order centers.
7. Higher-order centers supply certain functions that are not offered by lower-order centers. They also
provide all the functions that are provided in lower-order centers.
8. All consumers have the same income and the same demand for goods and services.

9. The
Theory • Centrality is the degree to which a place serves its surrounding area, and this can be gauged only in
terms of the goods and services offered. Clearly, there are different orders of goods and services:
some are costly, bought infrequently, and need a large population to support them (e.g. furniture,
jewellery); others are everyday needs and require a small population (e.g. groceries). From this two
concepts emerge:
1. The threshold population. The threshold is defined as the minimum population required for a
good or service to be provided that is, the minimum demand to make the good or service viable.
2. The range of a good. This is the maximum distance which people will travel to purchase a
good or service. At some range from the central place, the inconvenience of travel as measured in time,
cost and effort will outweigh the value of or need for the good.
• From these two concepts an upper and a lower limit can be identified for each good or service. The
lower limit is determined by the threshold, the upper limit by the range.
• Ideally each central place would have a circular trade area. It is obvious, however, that if three or
more tangent circles are placed in an area, unserved spaces will exist.
• In order to eliminate any unserved areas, the circular market areas must overlap and, since people in
these overlap zones will choose to visit their nearest centre in keeping with the assumption of
minimum movement, the final market areas must be hexagonal.
• The resulting hexagonal pattern is the most efficient way of packing market areas on to the plain to
ensure that every resident is served.

10. The Theory (in Figure)

11. Criticisms
1. The theory is not applicable to all settlements.
2. The economic determinism of the theory takes no account of random historical factors
that can influence the settlement pattern.
3. The theory makes unrealistic assumptions about the information levels and mental
acumen required to achieve rational economic decisions, even if profit maximization
were the only goal of human behavior.
4. The notion of a homogeneous population ignores the variety of individual circumstances.
5. Christaller’s model assumed relatively little governmental influence on business
locational decisions.
6. Consumers do not always visit their nearest store, and multipurpose shopping trips
often result in low-order centers being by-passed for low-order goods, thus leading to
their decline.

12. Application
• Central-place ideas have been employed widely in regional-planning schemes in the
USA, Canada, Africa, India, Europe and the Middle East. For example, an Israeli
settlement on the Laklish plains to the east of the Gaza Strip was based on a three-
level hierarchy of:
1. ‘A’ settlements of various types (including protective border kibbutzim) housing
immigrant settlers and serving as agricultural centres containing facilities used
daily;
2. ‘B’ settlements (rural community centres), each planned to serve four to six ‘A’
settlements and to supply facilities and buildings used by them once or twice a
week;
3. ‘C’ settlements (regional centres), towns roughly at the geographical centre of
their region, providing administrative, educational, medical and cultural facilities,
and with factories for crop-processing.
• The most clearly articulated application of central-place principles has occurred in
the Dutch polder-lands.

13. Diffusion Theories

14. • Bylund (1960) has proposed, within a
deterministic framework, six
hypothetical models of settlement
diffusion based upon his study of
early colonization in central Lapland.
• Each of his four basic models (shown
in Figure) differs in the number and
location of ‘mother settlements’.
• The process of clone-colonization
(model B) appears to imitate the
actual pattern of colonization most
closely, and this concept is developed
in two further models to replicate the
known settlement history of the area.

15. • The principles underlying these models have also been developed by Morrill (1962)
in a probabilistic simulation of central-place patterns over time.
• The idea behind the model is that the behavior of persons, as seen in the founding
and growth of settlements and transport lines, occurs gradually over time and
may be described as random within certain limiting conditions.
• The aim of Morrill’s approach is to account for the general pattern of settlement,
not the exact location of places.
• Morrill (1963) examined the spread of settlement in Sweden using this historical
predictive approach.
• He begins by acknowledging that as the number, size and location of settlements
in any region are the result of a long and complex interplay of forces.
• Any study which proposes to explain the origins of such patterns must take into
account four major factors: the economic and social conditions, the spatial or
geographical conditions, the fact that such development takes place gradually
over time; and there is an element of uncertainty or indeterminacy in all
behavior.

16. • The construction of a theory to explain the spread of settlement within a
territory also formed the basis of Hudson’s (1969) work in Iowa, in which he
attempted to integrate diffusion theory with central-place theory.
• Drawing on the work of plant and animal ecologists, he identified three
phases of settlement diffusion:
1. Colonization, which involves the dispersal of settlement into new territory;
2. Spread, in which increasing population density creates settlement clusters
and eventually pressure on the physical and social environment;
3. Competition, which produces regularity in the settlement pattern in the way
suggested by central-place theory.
• Empirical testing of these hypotheses using settlement data from six areas of
Eastern Iowa, at three different times between 1870 and 1960, found that the
suggested increase in settlement regularly over time did occur.

17. • Vance (1970) also employed an historical diffusion perspective to devise
a mercantile model of settlement evolution within a colonial setting. This
envisaged five main stages in the development of settlement systems,
in both core (home country) and periphery (colony):
1. Exploration. This involves the search for economic information by the
prospective colonizing power.
2. Harvesting of natural resources. This involves the periodic harvesting
of staple products, such as fish and timber, with limited permanent
settlement.
3. Emergence of farm-based staple production. Increased permanent
urban settlement permits export of agricultural commodities to the
mother country that supplies the colony with manufactured goods. The
seaports in the colony act as ‘points of attachment’ with the home
country.

18. 4. Establishment of interior depot centers. Settlement penetrates inland
along favorable long-distance routes that facilitate the movement of
staple products from the interior to coastal points of attachment which
also begin to develop manufacturing. Towns established at strategic
locations along these routes serve as ‘depots of staple collection’. This
period also witnesses rapid growth of urban industrial centers in the
home country to supply both the overseas and the domestic markets.
5. Economic maturity and central-place infilling. The growth of a
manufacturing sector leads to economic maturity accompanied by the
emergence of a central-place form of settlement pattern in which the
depots of staple collection take on a service function and develop as
regional centers. In time smaller central places are founded to serve
local needs. Overall, the spatial structure of the colonial urban network
is exogenic, being determined largely by external forces.

19. Closing Remarks
• Notwithstanding the analytical value of these theories, the great
variety of settlement forms and distribution would appear to lend
support to Bunce’s contention that ‘settlement patterns are the
product of the area which they occupy’ and Grossman’s view that
‘general laws are meaningless outside the specific cultural and
technological context’.
• Despite the pedagogic value of the seminal models considered above,
it is difficult to avoid the conclusion that a general theory to explain
the location, size and spacing of settlements is unattainable.

20. References
• Pacione, M. (2005). Urban
Geography: A Global Perspective.
Taylor & Francis. Ch. 6.
Lecture by A H M Nahid