In economic terms, a city as an interrelated network of economic markets, housing, labour, land, transport, and so on, situated in a limited spatial area.
Despite of fairly long history, urban development has only been in the last 100-150 years that urbanization has really gained momentum.
Miss Jacob's thesis is that cities grew out of trading centers where nomadic hunters met with local inhabitants who were willing to trade materials and other raw materials found in the area for food and hides.
After a time, traders were attracted to the trading center and some local producers turned to buying and selling. These groups eventually combined to create a merchant class.
Reasons For Urban Growth
- Economic and non-economic factors cause the growth of a particular urban area
- The nature of existing economic opportunities in a nation is a guide to the size and character of the future urban population, level of income, consumption needs, land use, etc
- The stage of development of that nation is important, since the less potential rate of urban growth than advanced industrial countries (the latter, a high proportion of population is already urbanized)
- Increased in real income (large demand for goods and services)
- Economic opportunities improved (attract additional labour from non-urban area)
Pattern of Growth Theories
The theory of urban growth is to understand the phenomenon of urbanization.
Four theories generalizing the pattern of growth of urban land use (The Urban Research by University of Chicago) have been recognized as follows:
Concentric Zoning Theory
The work of Ernest W. Burgess and based on empirical studies of Chicago, illustrated the typical process of urban growth by a series of concentric circles expanding radially from the central business district (CBD).
It was suggested that any city extends radially from its center to form concentric zones and that, as distance from the center increased there would be a reduction in accessibility, rents and densities.
Land use would assume the following forms outwards, the central business district (CBD), a zone of transition, an area of factories and low-income housing, an area of higher income housing and a commuter zone.
Axial Development Theory
This theory represents a natural progression of thought from the previous one because accessibility to single focal points is still basic premise (e.g. as physical distance, etc).
It has extension of each types of land use along the main transport routes, especially the fastest ones. This would result in a star-shaped pattern for the urban built-up area, the numbers to the star depending on the number of main routes into town.
Critisms of concentric zoning, regarding accessibility to places other than the CBD, will apply.
Sector Theory
Suggests that growth along a particular axis of transport usually takes the form of similar types of land use.
Each sector is of relatively homogeneous land use and expands outwards in a particular direction from the CBD. Empirical evidence for the sector arrangement was provided by patterns of residential land use.
The sector theory explains the pattern of urban growth from the point of view of changes in residential land use.
Residential area exhibits a tendency to segregate according to income and social position. If price and rents are taken to indicate qualitative differences in housing, persons in the highest income groups lives in houses commanding the highest prices and rents. Low-income area is located on the opposite side of the CBD to high-grade housing, near to concentrations of manufacturing industry.
The principle growth of an urban area takes place by a new building at the periphery.
Multiple Nuclei Theory
Harris and Ullman argue that in many urban areas there may be more than one local point and that each of the discrete nuclei influences the location of certain land uses.
In some urban areas such nuclei may have existed from the very beginning as when subsidiary settlements are absorbed into an expanding urban area to form secondary nuclei around which land use is intensified.
In other cases the nuclei appear with the growth of the urban area.
E.g. the growth of urban population in one part reaches a level, which will support a suburban shopping center of manufacturing firms find an advantage from being located together in an industrial area as they grow in number.
The larger an urban area becomes the more numerous and specialized the nuclei. The CBD need to be in the center of a city but as a result of asymmetrical growth it could be towards one edge of the built-up-area.
This theory allows the development of the most irregular pattern of urban land use because development can proceed from more than one center. In underlining irregularity of urban land use patterns it can be suggested that a particular pattern would have to be drawn to fit each urban area.
Such a conclusion overlooks the fact that urban land uses would be distributed according to the principles stated.
Thus accessibility considerations, opportunities for specialization, the importance land uses operate to determine land uses within any urban area.
