Image Processing Reference
as transportation improved, leading to spatial extensification of urban areas,
associated often with a decline in the population density in central areas. The
spread of cities beyond traditional core areas is also encouraged by the reluctance
to tear down old buildings and widen narrow streets, thus pushing economic activity
into newer places where a built environment can be created that is more accom-
modating of modern technology.
Overall, the limits of technology in the preindustrial era represented constraints on
the location and size of cities, and thus on the complexity of the city systems that
could develop in any given region. Modern technology, on the other hand, has virtu-
ally demanded the growth of the urban population both numerically and as a fraction
of the total population, and has given rise to numerous new forms of urban structure
in the process. Therefore, we should expect that, all other things being equal, modern
technology will be associated with considerably more complex forms of city systems
than was true in the preindustrial era. However, once again technology potentially
alters the expectation because improved communication means that the advantages
and disadvantages of particular city systems are evaluated quickly and that informa-
tion can be disseminated in a way that can influence policy makers and market forces
in the same way in disparate places. In preindustrial societies the slowness of com-
munication led to a greater variety of cultural responses to the organization of social
life and to a much slower diffusion of innovations.
Technology and Self-Sufficiency
The importance of modern technology is that it provides us with a set of clues
about how to redefine, or at least improve our definition of, an urban place.
Urban places are increasingly characterized by the kinds of infrastructure they
provide to their residents. To a degree, this is a function of self-sufficiency.
A truly non-urban place is one in which its residents are completely self-
sufficient, in that they grow their own food, have their own water supply,
create their own energy (largely from wood fires) and deal with their own
waste products. This mode of living represents the life that most humans who
have ever lived were born into. Yet, it is also a life that is precarious, because
it is associated with high death rates and low levels of innovation. At the other
end of the continuum is a place in which residents are completely dependent
upon strangers for virtually all of their needs - piped water, piped sewage,
landfills beyond the city limits, food brought to them from elsewhere in the
world, and energy sources that are generated from outside the region.
Urban-Rural Is Not Really a Dichotomy
The idea of a continuum suggests that urban and rural are, in fact, ends of a continuum,
rather than representing a dichotomy. Nevertheless, most countries employ a dichotomy
in the definition of urban. “Of the 228 countries for which the United Nations (UN)