ANDREA I. FRANK
POPULATION DYNAMICS AND URBAN GROWTH PATTERN
Cities are nodes of mans greatest impact on nature, the places where he
has most altered the essential resources of land, air, organisms, and
water. The city is the quintessence of mans capacity to inaugurate and
control changes in his habitat. Through urbanization man has created new
ecosystems within which the interaction of man, his works, and nature are
complex. This complexity - and the importance of our understanding it -
grows as cities burgeon in the modern world.
--Marcus and Detwyler
The Urban Age
In view of societal evolution urbanism is a very recent
development. Considering that in 1800 only a meager 3% of the worlds
population lived in cities over 100,000 (Detwyler & Marcus, 1972) - the
twentieth century may well be called the urban age. In 1969 Davis
speculated that in 1990 more than half of the globe's population would be
living in cities of 100,000 or more (Cities, 1969). This prediction was
remarkably good. According to World Resources Data Base (WRD), as of
1995, 45.2% of the worlds population is living in urban centers. The
portion of urban population in South America (78%), Europe (75%), North
and Central America (74%) and Oceania (71%) and the former USSR (68.1%)
lies well above this mark; whereas Africa and Asia still show percentages
under 40%. Within each continent we find a wide range of urbanization for
It can be generalized that countries with a currently low
percentage of urban population experience the highest annual change
rates. Urbanization is therefore more significant in those countries than
in countries with an already high percentage of urban dwellers. For
example, Canada, the United Kingdom, Australia, the US or Sweden had a
percentage of urban population of more than 70% in 1965. This figure did
increase only marginally over the past 30 years. Countries with less than
30% urban population in 1965 experienced dramatic changes (Table 1).
Urban Population as a Percentage of Total
Country 1965 1995 %Increase
United Kingdom 87.1 89.5 2.4
Australia 83.0 85.2 3.2
New Zealand 78.9 84.3 5.4
Sweden 77.1 84.7 7.6
Canada 72.9 78.1 5.2
Turkey 34.1 68.8 34.7
South Korea 32.4 77.6 45.2
Honduras 25.7 47.7 22.0
Kenya 8.6 27.7 19.1
Botswana 3.9 30.9 27.0
Table 1- Country Comparison of Urbanization Rate
With the earth's growing population the continuation of the
urbanization trend and of urban growth is more than likely to persist.
Urban form and development vary a great deal. In view of the complexity
of the system and the multitude of interacting variables it seems
presumptuous to think that urban dynamics and growth can be controlled
and governed. It is however assumed that certain measures and policies
could help influence changes toward a more favorable and "harmonious"
development and shape of urban centers. With most of our earth's
population living in urban areas, the creation of a livable and
environmentally sensitive urban habitat is not only a moral but a
survival need. Increasing the understanding of the
urban-population-environment dynamics might be a first step towards
addressing this demand. An improved insight in those dynamics then might
help to devise policy to manage urban development in a fashion that
sustains the environment, preserves valuable natural resources and
biodiversity and mitigates negative effects.
Urbanization: Factors and Problems
The reasons for urbanization are manifold. One reason for the
increase of the urban population is total population growth. The rise of
mercantilism drove the urbanization in 16th century Europe (Hartshorn,
1992). More recently, urban growth stems from the shift of labor force
from agriculture to industry and service sectors; the latter two are
generally located in cities or urbanized areas, thus serving as
attractors for human migration and agglomeration. Other motivations to
move from rural to urban settings are job opportunities and education.
The benefit of the city versus the country can be summarized as the
maximization of stimulation, exchange and opportunity with a minimization
of travel time (Register in Aberley, 1994). This is certainly one view.
During the early stages of European urban history the city represented
freedom. Still, city life today is associated with a sort of independent
and anonymous living.
The human-imposed order within the city boundaries suggests
security and safety from untamed nature or enemy forces. Modern man's
fear is derived from dangers within the city. In many cases the aspect of
safety and order of the urban center has lost its validity. The inner
city often is perceived as unsafe and dangerous. Other benefits, such as
minimization of travel time, are often offset by the increasing physical
size of the urban area. In a spread out multi-million person city that
covers several hundred square miles it can take considerable time to get
from one destination to another. Automobile travel is slowed down due to
speed limit and traffic density. With no efficient public transit system
in place it might take longer to cover the same distance than if one had
to commute a similar distance between rural villages.
Continued (rapid) urbanization generally poses a number of
problems. Housing and infrastructure has to be provided for an increasing
number of city dwellers. This requires planning and the resolution of
land use conflicts. If the influx of new urban residents exceeds the city
planners capabilities to plan lots and streets for new neighborhoods it
often results in poorly planned and uncoordinated growth development. In
so-called lesser developed countries (LDCs) with high population growth
rates, migrants with little and no economic resources often settle
illegally on vacant areas in, or adjacent to, large cities creating
pouvre barrios or squatter communities.
If the city does not meet the expectations for opportunities,
jobs and wealth, dissatisfaction can lead to criminal or aggressive
activities. Stimulation, while good and needed for human development also
has a flip-side. Life in a dense and crowded environment also can pose
enormous stress upon the city dweller, possibly leading to various health
and behavioral disorders such as depression, illness or aggression.
Cities use large amounts of energy, for industries and to heat
and light thousands of homes. The energy is often created by burning
fossil fuels, which leads to air pollution. Pollution of the air and
water, human and industrial wastes causes negative environmental
degradation and imposes on the quality of life and well being of urban
residents. Managing growth in order to mitigate environmental degradation
will be of utmost importance to ensure a livable urban setting for the
future (Hartshorn, 1992).
In summary, problems of urbanization are especially pertinent and
difficult to address in rapidly changing cities of the third World
(Cadman & Payne, 1990). These periods of rapid urbanization or
de-urbanization can be regarded as periods of transition. Transitions are
times of vulnerability; in the case of urbanization they are a threat to
the integrity and vitality of a city (Drake, 1992). Rapid urbanization is
potentially unhealthy and equally harmful to urban residents, the
functioning of the city and the natural environment.
A Morphological Approach to Population Dynamics, Urban Growth and Urban Form
Development of Urban form
Many studies of urban growth development and form in the past have taken
a historical or a functional perspective. The historical perspective
reveals a cycle of growth and decline, formation and restructuring of the
city (Cadman & Payne, 1990). Towns and villages have been categorized
according to physical growth pattern into cluster and linear band types
or hierarchies of rank-size (Hartshorn, 1992; Christaller et. al.). The
functional approach perceives cities as an organizing center, serving
typically a predominant function such as banking, administration, or
services. We distinguish trade, military, industrial or company towns and
many more. Geographers also have categorized cities in terms of their
spatial location as coastal or river cities and so forth (Hartshorn,
1992). While each of these different perspectives is interesting and
valid, they fail to address the system dynamics of urban development in a
more comprehensive manner.
Systems approach and Transition Theory
Marcus & Detwyler et. al. (1972, 1992) suggest viewing the urban
agglomeration as a dynamic system or even as an ecosystem. Systems are
not static, but generally evolve over time. At times, however, systems
change rapidly due to a changing systems component (i.e. population). In
terms of urban form other systems components that trigger change are
transportation modes and technology amongst others. From a systems
perspective of view, periods of change can be viewed as temporarily
bounded or transitional (Drake, 1993). Periods of rapid change will be
followed by periods of relative stability. Transition theory assumes
interdependence and relationship between transitions of different sectors
such as agriculture, education, etc. This means the amplitude and time
frame of one transition, i.e. urbanization is likely to be influenced by
others, such as education. Implications for society may be enhanced or
reduced, if the timing of transitions can be influenced by policy.
Urbanization Transition and Urban Shape
This study proposes to look at urbanization from a spatial point
of view investigating the linkage of population growth, urbanization and
urban shape. It will explore population changes in time and the
corresponding spatial changes of urban form. The investigation is based
on the premise that urban form is the physical manifestation of
urbanization. Urban growth is a result of population growth, rural-urban
migration and urban expansion. The author believes that the rate and time
of change in those dynamics and the accompanying fringe conditions
(landscape, technologies, climate etc.) will determine the urban shape
(Figure 1). In a generalized way, these factors can be attributed to
either the natural environment or the human society. Although the
determinants for urban form of human origin, such as technology,
transportation systems and culture may dominate, topography and land form
are especially influential in early spatial patterns (Detwyler & Marcus,
Figure 1 - Influences on Urban form
Towards a morphology of urban form
The dynamics of urban-population-environment systems are complex.
Transition theory at the global level and at the local level will be used
to investigate urbanization trends. In conjunction to the urbanization
data a number of factors that may influence urbanization, such as
industrialization, transportation technology etc. will be explored. These
factors are identified and linked to physical development pattern. It is
assumed that different values of factor sets will result in different
physical growth pattern. Furthermore, it is assumed that the timing of
transitions in other sectors will influence the growth pattern of urban
agglomerations as well. An attempt is made to develop a morphology of
urbanization stages based on change and behavioral similarities at a
national level. The categorization of urbanization stages will become a
framework from which a morphology of urban development pattern at the
local level can be devised. This local morphology probably will be
correlated to behavioral pattern (i.e. traffic) and pattern in the
environment (i.e. topography) if appropriate [Adams, ref. comment]. The
author hopes that a general survey of structure and form of urban
development could be helpful to derive a typology or classification of
certain trends. In the long run, a morphological study may help to
indicate development pattern that are preferable in respect to newly
developed environmental value systems.
In morphological terms a range of different classes of cities is
imagined. A morphology could contain simple size distinction (small,
medium, large) as well as functional-structural categories (old, new,
dense, dispersed, high-tech, low-tech, etc.). In terms of development,
transition theory will help to envision likely future development
depending on the initial conditions of an urban system. Since technology
and industrialization are thought of being major shape factors of urban
growth this study starts developing an initial morphology of urban form
with respect to the changes in transportation modes and urbanization. In
particular individual motorized transportation is investigated for its
impact on urban form. When linking urban growth and transportation
technology the following scenarios for urban shape development can be
constructed. A possible test for these morphologies, would be a study of
urban shapes comparing urbanization and development pattern.
Three initial morphologies for urban shape and change of
transportation modes were developed:
1) Introduction of individual automobile transit prior to major urban
- increase in urban area
- decrease in density
- low overall urban density (except may be historic core)
- transportation arterial location greatly influence urban form
- depending on the size, satellite-like subcenters might form.
The new urban growth is build for the automobile.
2) Introduction of individual automobile transits during the urban growth
- a chaotic state (planners are caught in the dilemma between accommodating
people or cars)
- dense traffic
- major pollution
- urban area, that is structure in an ad hoc fashion probably with
- opportunities and dangers depending on economic situation and policy
3) Introduction of individual automobile transit post urban growth period
- major redesign of the city structure (retrofitting the city for the car)
- relative high density
- traffic congestion
- pollution and noise (if not mitigated by policy)
- can potentially degrade quality of the city structure
Note: It is very likely that the effect of the transportation
technology transition varies depending on the size of the city or town. A
small town will be less affected by it than a large town. This is a
matter of geometry and existing density. For these examples growth is
unrestricted by landscape, political borders, or policies. Doxiadis
organic growth model also predicts distortions along transportation
routes at advanced stages of urban development (1968).
Figure 2 - Morphologies
The study uses various analysis techniques to explore the
feasibility of linking urban transition and urban form to a shape
development morphology. It looks at many different aspects of the
problem, trying to understand it without however being exhaustive or
comprehensive. Hopefully, some different views regarding urbanization can
Methodological Approach and Data
The methodological approach in this study is twofold. Global and
local level data will be investigated. This is to emphasize the scale
dependence of the issue.
First, a general investigation of urbanization at the global
level is conducted. This is to establish a general notion of the linkage
between population growth and urbanization While there is a global
urbanization trend, we probably can observe the urbanization transition
at different stages, its beginning, in full force or at its conclusion
for different countries. The global urbanization trends are investigated
looking at time series data from the World Resource Data for 42
Countries. Urban, rural and total population development are explored and
displayed. Urbanization factors that are viewed as influencing
urbanization and urban form will be investigated in relation to the
urbanization transition in the hope to discover correlation and linkages.
One of those factors is the level of technology available in the country.
Secondly, local level data will be investigated in respect to
urban development and urban shape. The urban development of 5 major US
cities over the past four decades serves as starting point for this
investigation. Then, a more in-depth study of urban shape is conducted
comparing Boston, MA and El Paso, TX. The study is based on US census
data. An attempt was made to link the results of the investigation to
urbanization factors that were thought to be shape-determinants.
Urbanization at the Global Level
National Comparison of Urbanization Levels
On the basis of availability of desired data, a total of 42
countries were selected from the WRD (see Table 2). Initially
urbanization information was mapped on a world projection using ATLAS GIS
for Windows. Two other factors were mapped in succeeding maps; the
I_index and a correlation of the urbanization and I_index. The I_index
was calculated to provide some sort of measure for industrial
productivity by dividing Gross domestic Product (GDP) industrial share
(%) by the workforce in the industrial sector (%). The index is adjusted
through multiplication by total number of workforce and division by total
GDP. Supposedly this index will give a indication of the extent of
industrialization. With at high output of the industrial sector shown by
a relative large share of the total GDP achieved by a small share of the
workforce should result in a large index. It is assumed that when few
people achieve a large proportion of GDP it is a result of automation and
high technology. This would indicate a high level of technology.
Map 1 presents a general overview. It displays the 42 selected
countries according to the proportion of people living in cities. The
distribution for the four ranges was customized for the purpose of this
display. The 8 countries at the top of the list in terms of percentage of
their total population living in cities are in descending order:
Singapore, Belgium, Venezuela, Uruguay, United Kingdom, Netherlands,
Denmark and Australia. In terms of land area, except for Australia, these
countries are fairly small, suggesting that there might be a correlation
of land area and degree of urbanization. Australia then would be an
outlier, since despite large areas of land most people live in cities. On
the other hand, Australia might be right in the ball-park, when using
hospitable area instead of total land area. Due to the limited data used
for this study, however, the author opted not to pursue any further
investigations in this direction.
The display of the urbanization transition for the 42 countries
reveals three distinct pattern. Urban, rural and total population
development is plotted over time (see Figures 3a, 3b, 3c).
This pattern shows a declining rural population and an increasing urban
population. Around 1990 to 2000 the total population growth seems to
level or decline. Pattern A countries are reaching or have reached the
end of a fairly typical urbanization transition. The urban population
percentage stabilizes at a fairly high level of 70% of the total
population or higher. Over the transition period the rural population
dropped to a fairly low overall level. These countries typically have a
high I_Index (Figure 3a).
Pattern B countries are at the beginning or in the midst of their
urbanization transition. A high growth rate for the urban population is
accompanied by a (soon) declining rural population. The total population
growth rate is quite high (3%++). The end of the transition in this
pattern is projected beyond the year 2010 or later (all data and
projections WRD). These countries typically have a low I_Index (Figures 3b).
Pattern C countries have a very low stable rural population. The urban
population is however growing in linear fashion. There seems to be no
leveling or change in that trend for the next two to three decades (WRD
prediction). All population increase seems to occur in the cities. The
countries with this urbanization pattern are Australia, Canada and the
USA, three major immigration countries (Figures 3c). This suggests that a
large proportion of the urban growth is due to inmigrating foreigners.
Figure 3a - Pattern A
Figure 3b - Pattern B
Figure 3c - Pattern C
Urbanization and Technology
Technology and industrialization seemed to be major factors that
drove urbanization in the past (Hartshorn, 1992). These factors had a
great influence in changing land use pattern (Sinclair, 1967). A further
investigation of the link of urbanization to industrial
production/technology appears promising
Map 2 displays the calculated I_Index (Industrial GDP/workforce
industrial share). The high ranking countries are what is often
designated as the Industrial Nations. The order is somewhat surprising
with Norway at the top and the US ranked sixth. The listing might appear
skewed since strong industrial nations such as Switzerland and Germany
could not be included due to the lack of comparable data.
Map 3 shows the correlation between the I_index and the percent
urbanization for each country. The findings are interesting. There is a
group of three countries Norway, Finland and Japan with a correlation
factor of 1.5 or less, meaning that the percentage of urban population
and the numerical value of the I_index are almost the same. A high
correlation factor indicates a discrepancy of nominator and denominator.
This means that despite a low level of technology and industrialization
there is a high percentage of people living in urban areas. This means
that urbanization preceded industrial development and must have been
triggered by different factors. It also means that urbanization will
occur under different premises than in the countries with a low
correlation factor. Countries with a high factor are in descending order
Pakistan, Sri Lanka, Honduras, Philippines, Romania, Egypt, Panama, El
Salvador, Costa Rica, Turkey, et. al. Most of those countries are at the
beginning of their urbanization transition (Figures 3a-c, 4a, 4b, 5a, 5b).
A complete list of countries with their ranking of urban population,
I_index etc. is shown below.
Rank # Country Urban Popin % I_Index % Urban/I_Index
1 Norway 77.002525 64.9283 1.1861141
2 Japan 77.943899 55.4794 1.4051541
3 Canada 78.137155 51.4949 1.517521
4 Belgium 96.650384 47.3575 2.0411908
5 Finland 60.285375 46.0019 1.3105516
6 United States 76.237184 45.9387 1.6598559
7 Sweden 84.737262 45.6385 1.8570515
8 France 72.788174 45.0832 1.6146445
9 Netherlands 88.915414 44.6254 1.9927255
10 Denmark 85.477658 41.7588 2.0473691
11 Italy 70.540494 40.9309 1.7247065
12 Austria 60.628419 38.8964 1.5589719
13 Australia 85.167412 37.2962 2.2839209
14 United Kingdom 89.461725 34.704 2.5781477
15 Spain 80.652307 27.9247 2.8886929
16 New Zealand 84.290541 27.6005 3.0190022
17 Singapore 100 19.9111 5.0226017
18 Mexico 75.298388 18.8261 3.9996807
19 Venezuela 92.87809 16.3011 5.6980423
20 Uruguay 90.301318 13.6092 6.6398028
21 Trinidad&Tobago 66.50038 13.3537 4.9880179
22 Greece 65.034624 12.9655 5.0181037
23 Korea, Rep 77.628259 12.3138 6.3061137
24 Guatemala 41.465022 11.3321 3.6597548
25 Ecuador 60.615801 11.316 5.3594873
26 Colombia 72.721575 10.9699 6.6351802
27 Ireland 58.402998 10.6801 5.4684455
28 Portugal 36.361797 9.92898 3.6655037
29 Paraguay 50.684652 7.95855 6.3754279
30 Poland 63.868236 7.62871 8.3816583
31 Jamaica 55.359246 6.92128 7.9998911
32 Turkey 68.767733 6.86745 10.024451
33 Panama 54.870252 5.02267 10.930329
34 Costa Rica 49.707944 4.94479 10.144478
35 Romania 56.183791 4.44702 12.625571
36 El Salvador 46.67129 4.41119 10.583059
37 Egypt 44.763239 3.81796 11.748882
38 Indonesia 32.529271 3.63699 8.936613
39 Philippines 45.677693 3.61282 12.653101
40 Honduras 47.654155 3.47418 13.733186
41 Pakistan 34.692607 1.80723 19.273671
42 Sri Lanka 22.3809 1.58441 14.165127
Table 2: Industrial GDP/Industrial workforce Index
Different Urbanization Catalysts
As a consequence of the map evaluations, the countries with the
extreme values of the urban - I_index correlation appear to be
interesting in terms of transitions. The charts below show the
urbanization transition for Norway, Finland (%Urban/I_Index factor of
1.18 and 1.31) and Pakistan, Turkey (%Urban/I_index 19.27 and 10.02). The
most remarkable difference between the two pairs seems to be that the
energy consumption seemed to raise parallel to the urbanization in Norway
and Finland. Both countries show a similarly high per person consumption
of energy of about .2 Terajoules in 1991. For Pakistan and Turkey the per
person energy consumption in 1990 is about 1/10 of the energy consumption
observed in the two industrialized nations. Turkeys urbanization level
(68%) is higher than Finland's (60%). The climatic differences may
account only for some of the difference.
It is assumed that this difference in energy consumption will
lead to a dramatically different urban shape. Since data for city
density, population and shape is difficult to obtain in the short period
of time available for this project the impact of technology, i.e. the
availability of the automobile (expressed also through an increased
energy consumption per person) will be investigated in a modified way; at
the local level (for US cities).
Figure 4 a - Urbanization and Energy Consumption Trend in Norway
Figure 4 b - Urbanization and Energy Consumption Trend in Finland
Figure 5 a - Low Energy Urbanization in Turkey
Figure 5 b - Low Energy Urbanization in Pakistan
The urbanization at the local level is examined for five US
cities using census data. The urbanization development of three cities
with a population of about 1/2 million in 1990 was traced, as well as
that of two multi-million person cities. As assumed earlier, despite an
increase of urban population at the national level, some cities decline
(Figure 6). Some of the cities that had major growth before the advent of
individual traffic and others grew in the automobile area. Density seems
to be one factor that impacts urban form. In comparing the growth rate -
density correlation of 5 major cities we find a strong correlation of
rapid growth and high spread. However there are many more factors and
additional research is needed.
Figure 6a - Urban population development
Figure 6b - Urban population development
Figure 7 - Population Density Development
The generalized data however may be misleading. Therefore a
comparison of spatial density distribution was conducted for two of the
five cities investigated.
City Shape: Boston, MA versus El Paso, TX
The theory, just to recap, is that the time when the urbanization
transition occurs will have a significant impact on the urban shape that
is formed. It is in fact the context or conditions under which
urbanization occurs that will impact the form. Technology is viewed as
one of the important shape factors.
With Boston, MA and El Paso, TX we have two cities that have
approximately the same size by population; with Boston having a
population of 551675 in 1992 and El Paso having 543813. Both cities are
constrained on how freely they can grow in some sense, with Boston having
the Atlantic Ocean restricting growth to the south and east and El Paso
having the Mexican border. In these terms the two cities are comparable.
However, Bostons growth rate over the past 40 years was moderate or even
declining, while El Paso went through a major post World War II growth
spur. In 1940 El Paso had a population of about 100,000 (D'Antonio &
Form, 1965). Boston's population exceeded 100,000 between 1840 and 1850
(Kennedy, 1992)1. The existing urban shape of the two cities is very
The diagrams below map the shape components of population density
and spatial distribution for Boston and El Paso. They were created using
1990 US census data for the city proper boundaries. At the block group
level, population data, area, longitude and latitude for the centroids of
each block were collected by extracting the appropriate files in
electronic form and saved as text files. At this level 100% population
count data is available. Block groups have an absolute population count
between 700 and 2000 persons. The granularity of this data level ensures
enough data points to get fairly accurate results for a density mapping.
700 + data points (blocks) were identified for Boston and 600 + for El
Paso. However the variation of population within each block was felt to
be too large to merely map the population. Thus, the delimited text files
were read into a spreadsheet program (EXCEL) and reformatted for import
in a statistics package (SYSTAT). Within the statistics package a number
of computations were performed to calculate the population density per
square mile within each block.
A simple no-frills 2 dimensional plot was chosen to display the
data spatially. The latitude variable was chosen for the y-Axis and the
longitude variable was plotted on the x-Axis. The level of density is
distinguished by color (Figures 8a,b) and size (Figures 9a,b) of the
symbol plotted on the centroid of the each block within the citys
jurisdiction. For representation purposes it was necessary to multiply
the population density per square mile with a factor of 1/1000 to ensure
the variable was in a suitable range. The data for both cities was forced
onto the same scale in order to make the graphs more easily comparable.
Although the plot where density symbols are sized by value evokes
a more shape like image this might be deceptive. This is not the real
city shape. The density is so high that the symbols overlap or touch each
other creating a black seemingly solid city. The colored plot may be more
honest however it is somewhat hard to translate it into a meaningful
The Boston shape plot below shows a very dense, and compact city
shape with a high population density. Most dense areas are located in the
older parts of town. Some less dense areas are found in southern parts of
the town where the city extends into more rolling land.
In contrast, El Pasos population density on average is 1/5 or
less. The urbanized area is spread out along the major arterials. There
are some areas of higher density, curiously enough one at the eastern
fringe of the city.
Figure 8a - City of Boston Shape in 1990 (Density by Color)
Figure 8b - City of Boston Shape in 1990 (Density by size of symbol)
Figure 9a - City of El Paso Shape in 1990 (Density by color)
Figure 9b - City of El Paso Shape in 1990 (Density by size of symbol)
This paper is but one little puzzle piece in gaining insight into
the urban-population-environment dynamics and especially the linkage of
urban development and shape. Despite the rudimentary results, some
thoughts on policy implications are presented. Many more issues became
obvious for future research.
Discussion of Results
While globally there is a definitive trend towards urbanization,
the urbanization transition is already concluded in some of the countries
investigated, such as Japan, Denmark, the UK. Other countries are at the
beginning or in the middle of the urbanization transition, such as
Pakistan, Indonesia, and many more. The further course of the
urbanization transition in these countries in terms of amplitude and
speed will depend on the course of their demographic transition. The
sooner overall population growth can be slowed the sooner the
urbanization transition will level. It is likely that the urbanization
transition will lag behind the demographic transition for a few decades
while rural to urban migration persists. A general time frame for this
lag could be derived from looking at industrialized nations which have
gone through both transitions successfully (Japan, Denmark, Norway).
At least three countries could be identified that go through a
somewhat distorted transition, which are Australia, Canada and the US.
These are major immigration countries. Urban population increases in a
linear fashion, while the rural population remained constant for the past
45 years. Besides rural to urban migration of younger members of the
population, most immigrants seem thus to move to cities. Ports of entry
and coastal cities are likely to grow more than cities in the interior of
a country, since these are the places where immigrants naturally arrive
and mostly settle.
Depending on the specific characteristics of a country it can be
assumed that between 80% and 90% of a country's total population will
live in cities and urbanized areas. Some places with stringent land
constraints will reach virtually 100% urbanization such as Singapore and
Hongkong. Country specific characteristics influencing how high exactly
the percentage of future urban population will be could possibly be
derived from a conglomerate of factors such as landscape, level of
technology, historical patterns of settlement, culture, available land
area, total population density, policy and others. The author can only
speculate at this point about the importance of each of those factors,
but future research might be able to show patterns of development and
correlation, particularly between land area, density and the total
In comparing the urbanization of industrialized nations with
those of lesser developed countries it becomes quickly obvious that the
urbanization happens under different conditions. The study looked at just
one factor, which was energy consumption. In Turkey for example, the
overall urbanization is at a higher level than in Finland - however with
only a 1/10 of the energy consumption/per person. Urbanization in Turkey
is based not necessarily on industrialization and improved technology
(Turkey's relative low I_index also points to that direction). Urban
shapes and urban living thus will look different in those countries. As
Sinclair (1967) pointed out J. von Thunens land use model does not apply
any more for the US or other industrialized nations but may be still
valid for lesser developed countries. With urban expansion due to rapid
urbanization it will be interesting to see, if new and what values will
govern the development. Comparative investigations of city shapes and
form in countries with high respectively low energy consumption could be
an interesting future research topic.
In terms of all transitions the issue of scale is important.
While in general, the urban population in the US is increasing, locally
decline is also observable as can be seen for the development of Chicago
and Boston. Since both cities are nuclei of larger metropolitan areas the
decline of center areas also could be viewed as a decentralization and
dissemination trend. While studies in the past were successful in
providing empirical data on the "flattening density function" and post
World War II suburbanisation (Mills, 1969; Newling 1966), the causes for
the trend are not agreed upon.
The local level research conducted for US cities and the shape
investigation for Boston and El Paso in particular suggest that it
matters when and under what conditions urbanization and urban growth
occurs. The much older city of Boston experienced major growth and land
expansion in the past century. Due to the relative limited and slow modes
of transportation at the time, Boston's density is high, even today. In
comparison, El Paso's major growth spur occurred post World War II where
a change in technology brings about cost efficient personal
transportation. At a comparable population size in 1990 (ca. 500,000)
urban densities of El Paso are about 1/5 of Boston's densities. Figures 8
and 9 show the differences clearly. Doxiadis organic urban growth model
(1968) anticipates a distortion of urban growth away from a compact form
along radially outbranching transportation arterials, however not to the
extent observed for El Paso.
The shape development analysis conducted for this study has
several backdrops. While for El Paso the city limits and the urbanized
area are fairly congruent, it is not for Boston. The area of Boston
proper did not expand since 1912 (Kennedy, 1990). So, in order to examine
the shape of urban growth development it probably would be better to look
at the shape of the metropolitan urbanized area rather than city limits.
Data availability is a problem, since census tracts and jurisdictional
boundaries do not necessarily reflect urbanized land and its boundaries.
Remote sensing and satellite imagery might overcome this problem, however
since this data has been only recently released to the public time series
over decades are a problem.
There are two types of policy recommendations: Country and Local
Level. The suggested policies are very general at this point. They aim at
improving the quality of urban agglomerations. This is defined very
roughly as lowering the negative impact on the environment and decreasing
the energy/resource exchange flows between the urban ecosystem and the
surrounding ecosystems, mainly by looking at shape and density of the
city. The recommendations are based on the broad (and maybe at times
invalid) assumption that a denser and more compact city is likely to be
more sustainable (Dantzig & Saaty, 1973)
Country Level Recommendations
It seems sensible to categorize the policy recommendations
according to the stage of urbanization a country or nation is at (Pattern
A, B, C)
Pattern A (Concluding Urbanization Transition)
=> Stabilize status quo (you do not want to have cities disintegrate
after booms, marching right into the next transition)
Improve efficiency of urban city (lower emission, water use, public transit)
Mitigate environmental effects in surrounding areas
prepare for downsizing of the city or industry
consolidate metropolitan areas and provide for coordinated strategies
Pattern B (Starting Urbanization Transition)
=> slow urbanization down, or at least try to influence development
Improve opportunities in the country side
make vision plans (although there seems to be no time)
provide public transit
promote density and neighborhood clustering, decentralized
avoid depletion of environment
Pattern C (Immigrant Countries)
=> try to influence urban development
provide public transit
promote density and neighborhood clustering, decentralized
avoid depletion of environment
Local Level Recommendations
Local recommendations must be much more specific to the individual
situation of the city.
Much more work in terms of developing urban shape morphologies has to be
done. The author envisions that harmonious correlation can exist between
urban form and environmental features. These harmonious correlation will
be perceived as beautiful and particularly pleasant. It also could be
characterized as being stable and sustainable. Or yet in other words, a
preferable city shape is achieved by optimizing the urban metabolism2 for
the surrounding landscape. During rapid changes of either the environment
or population (characteristics) the harmony of this correlation will be
disturbed. The author further expects to find different patterns and
correlation at different scales. So the harmonious urban-environment
pattern will be different for a population of 10,000 or 100,000.
A harmonious relationship between urban agglomeration and
environment can be described as follows:
the urban form complements or assimilates the landscape, i.e. in color,
form, character and scale3.
the size of the city and its energy and resource demands do not cause
drastic changes in the landscape.
Beauty, harmony and pleasantness are difficult values to measure.
It is may be possible to find indicators such as crime rate, rating of
quality of live, migration rate, traffic congestion to evaluate the level
of compatibility of the urban system at its current stage with its
surrounding environment. For the environment measures of biodiversity,
decline or increase of renewable resources, fertility of the land, need
to fertilization in agriculture etc. Since both factors are interrelated
a depletion of the natural resources in the vicinity of an urban
agglomeration may as well further decrease the quality of life in a city.
As described earlier, urban form can be conceived as a result of
the different factors such as culture, technology etc. (Figure 2). Cities
in the mountainous countries like Austria or Nepal and Tibet will have a
different shape than a city in a desert landscape. Growth pattern and
urbanization pattern will be different as well. It is much easier to
build a city in a valley on flat ground than on the slope of the hills.
But flooding of rivers in this valley might be a threat and the valley
ground must be kept free from development for agricultural usage. Diverse
and rugged topography might favor many smaller town over one or two very
In contrast, the desert landscape might favor larger
agglomerations along a river or at some other water source. It will be
easier to distribute the water within a large city than build a pipeline
to supply many smaller towns dispersed in the landscape.
Technology is an important modulator of urban form. However, it
tends to exert an increase in energy consumption that might be
counterproductive in developing sustainable cities.
1. Boston and El Paso are different in age. The settlement of Boston
began around 1630. Boston reached its peak in terms of spatial extend of
city limits in 1912. The first permanent settlement on the present site
of El Paso was in 1827. It was known by its present name by 1859 and
formally chartered as town in 1873 (Kennedy, 1992; et. al).
2. Urban metabolism views the city as an organism, an open system, with
inputs and outputs from and to the environment (H. Girardet in Cadman &
3. The conceptual idea of complementation of man-made world and nature is
discussed in Norber-Schulz (1984). The structure of the natural place is
complemented by either adaptation of the same structure in the man-made
artifacts or contrasted; i.e. diverse landscape with multiple features is
"harmoniously" complemented by a small scale architecture with lots of
detailing like we find it in Norwegian wood carvings. The large scale
desert landscape is complemented with geometrical simple artifacts,
straight lines, square features, monumental. etc.
Aberley, Doug ed. Futures by Design. Philadelphia, PA. New Society
Batty, Michael and Paul Longley. Fractal Cities. Academic Press. 1994.
Cadman, David and Geoffrey Payne (eds.). The living City - towards a
sustainable future. New York, NY. Routledge, Chapman and Hall Inc. 1990.
Cities. Scientific American. New York, NY. Alfred Knopf. 1969.
County and City Data Book 1956. A statistical Abstract Supplement.
Department of Commerce. Buereau of the Census. United States Printing
office D.C. 1957.
County and City Data Book 1962. A statistical Abstract Supplement.
Department of Commerce. Bureau of the Census. United States Printing
office D.C. 1962.
County and City Data Book 1972. A statistical Abstract Supplement.
Department of Commerce. Bureau of the Census. United States Printing
office D.C. 1973.
County and City Data Book 1994. A statistical Abstract Supplement.
Department of Commerce. Bureau of the Census. United States Printing
office D.C. 1995.
Detwyler, Thomas R. and Melvin G. Marcus. Urbanization and Environment:
The physical Geography of the City. Belmont, CA., Duxbury Press. 1972.
Dantzig, G. B and Thomas L. Saaty. Compact City. San Francisco, CA.
Freeman and Company Inc.. 1973.
Doxiadis, C. A. Ekistics: An introduction to the science of Human
Settlements. London, Hutchinson. 1968.
Drake, William D. Towards Building a Theory of Population Environment
Dynamics: A Family of Transitions. In: Population - Environment Dynamics.
Ann Arbor. University of Michigan Press. 1993.
Frank, Andrea I. In Search for Pattern: An analysis of socio-economic
Data: Genesee County, Michigan. Unpublished term project. Engineering
503, University of Michigan, Ann Arbor, MI. Fall 1993.
Frankhauser & Sadler. Fraktales Stadtwachstum. in ARCH+ 109/110, Dec 1991.
Hartshorn, Truman A. Interpreting the City: An Urban Geography. New York,
NY. John Wiley. 1980, 1992 2nd ed.
Johnston, R.J.. Spatial Structures: Introducing the study of spatial
systems in human geography. Methuen & Co. ltd. 1973.
Kennedy, Lawrence W. Planning the City upon a Hill - Boston since 1630.
Amherst, MA. The University of Massachusetts Press.1992.
Mills, Edwin S. "Urban Density Functions". Urban Studies. Vol 7. pp 5-20.
Newling, Bruce. "Urban Growth and Spatial Structure: mathematical models
and empirical evidence. Geographical Review. Vol 56. pp 213-225. 1966.
Norberg-Schulz, Christian. Genius Loci: Towards a Phenomenology of
Architecture. New York, NY. Rizzoli International Publications, Inc. 1984.
Sinclair, Robert. "von Th|nen and Urban Sprawl." Association of American
Geographers Annals. Vol. 57. pp 72 -87. 1967.
State and Metropolitan Area Data Book 1986.
v. D'Antonio W. and William H. Form. Influential in two Border Cities: A
study in Community Decision - Making. University of Notre Dame Press. 1965.