The document discusses three models of city structure: 1. The concentric zone model proposes that land use is arranged in concentric zones around the central business district (CBD). 2. The sector model argues that urban expansion occurs along transportation lines in different sectors. 3. The multiple nuclei model claims that urban growth happens around several distinct nuclei, like a market, village, or factory.

1. 5-CITY STRUCTURE
MODELS

2. City structure models
There are three foundational “city structure models” in urban geography
1. Concentric Zone Model
2. Sector Model
3. Multiple Nuclei Model
The Concentric Zones model
• This emerged from a study of Chicago by Burgess (Parker et al., 1925). It is really the
first set of ideas towards the theoretical understanding of the city and was an
application of Von Thunen’s Theory relating to rural land around city.
• It postulates that urban land use is arranged around a single center the (CBD). It
suggested that any city extends readily 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.
• There would be declining proportions of recent immigrants; delinquency rates and
poverty and diseases as distance increase from the center.

3. Zone 1 – CBD- is the hub of all urban
activities including Financial,
economic, social and recreational
may have some light Manufacturing
industries.
Zone 2 – Transition ZoneComprises
of areas of residential deterioration
As a result of encroachment of
business and Industry activities from
the zone and usually Occupied by
first stage migrants
Zone 3 – Low Income Housing, Independent
working men’s homes Comprising largely the
residence of 2nd Generation migrants into the
city.
Zone 4 – Medial Income Housing - Contains
the residences of the middle class Occupied by
managers, clerks, salesmen and professional
Zone 5 - High Income Housing
-High Income - Commuter, zone is a
high of concentration of hamlets
which serve as Dormitory suburbs
for the wealthier city Dwellers.

4. Findings- the zones are not static, as
each tends to expand its area by the
ecological process of invasion and
succession. In its modified form, the
theory is descriptive showing how
rather than why urban growth takes
place.
Criticism
• Land use with many parts are wide
heterogeneous
• Shops, offices, factories, and housing
may juxtapose
• It ignores physical features takes
little account of industrial and
railway use and disregard the effect
of radical route ways up on land
values and uses.
THE LOGIC BEHIND THE MODEL

5. ACTUAL LAND VALUES IN SAN FRANCISCO 1926-27
Note prominent shopping corridors complicating the zonal pattern and driving
the formation of sectors

6. The Sector model
• The sector theory was presented by Hoyt, and propounds that urban expansion has
“axial growth, pushing out from the center along transportation lines.”
• The theory postulates that growth takes place along a particular rent way takes the
form of land use already prevailing and that each sector or relatively homogenous use
extends outward from the center.
• The theory was meant to be an alternative to that of Burgess. The effect of land pricing
leads to the occupation of the central zones by CBD function, as it is the only function
that can afford its rent.

7. • On the other hand, the major lines of
transportation constitute lines of least resistance
for growth in addition to there being important
arteries along which similar types of land use are
situated. The result is the emergence of a star
shaped pattern of city growth in which different
types of land use radiate from the CBD along
particular sectors towards the periphery of the city.
• It highlighted that compatible land use would lay
adjacent to each other – e.g. (warehousing, light
manufacturing and low income.) and incompatible
use will be repelled. Residential use will tend to be
segregated in terms of income and social potential
and will expand in different directions in different
parts of the city.

8. SECTORS AND ZONES IN A REAL
CITY (CHICAGO)
Criticisms
• the same like that of the concentric zone and while recognizing the relationship
between accessibility, land use and density. Hoyt believed that the
interdependence of the variables expresses itself differently in terms of spatial
structure.

9. The Multi Nuclei -model
• The multi - nuclei theory produced by Harris and Wolman is based on the assumption
that urban growth takes place around several distinct nuclei.
• The nuclei could include the first urban settlement (probably a market location), a
nearby village, a factory a mine, a railway terminal or water side facility ultimately,
they would be integrated into one urban area largely agglomerated by residential use
and intra – city transportation.
• The original nuclei would help to determine current use, e.g. the market town might
become the CBD; the village and outlying a business distinct, the factory site might
evolve into an area of heavy industry.
• Within the urban area, compatible uses are attracted to each other e.g. low income
residential land would be close to whole selling and light manufacturing and near heavy
industry, and the medium and high income residential area, would surround the
outlying business distinct. Incompatible uses would remain far apart e.g. high income
housing and heavy Manufacturing.
• The number of nuclei would be generally grater in large urban areas than in small cities
and there will be a greater degree of specialization with each nucleus.

11. Factors affecting where the richest families will live
• Lower cost of land,
• Newer infrastructure,
• Access to desired facilities and geographical locations (what are these?)
• Negative perception of certain social groups (racism and classism),
• Status-seeking behavior,
• Willingness and ability to commute.
Factors affecting where the poorest families will live
• Scarcity of affordable housing,
• Inability to avoid inadequate or decaying infrastructure,
• Inability to maximize access to desired facilities,
• Spatial avoidance by those in more favored groups,
• Ability/inability to commute (creates two zones of low-income housing).

12. Conclusion
• Theories of urban spatial structure are as much descriptive as analytical.
• They explain how cities change their forms, and very rarely will a single theory be
adequate in this task.
• The concentric zone while recognizing that the transitional zone experiences
deterioration prior to even tide development ignores the same trend occurring
elsewhere e.g. rural –urban fringe.
• More of the theories explain satisfactorily the significance of sub – centers to urban
growth and none gives attention to agglomeration.
• Most ignore the important changes that occur within the CBD which affect the urban
area as a whole.
• More importantly all fail to consider the process of decentralization.