“INTERNAL STRUCTURE OF URBAN
AREAS, DENSITY PATTERN,
LANDUSE CLASSIFICATION &
B A SIC
TER MIN OLOGY
“INTERNAL STRUCTURES OF URBAN AREAS”
THE ELEMENTS OF STRUCTURE
Assume the spatial separation of all people and all the facilities that
they need in order to live in both the biological and cultural world.
The sum of all the distances between each person and each kind of
facility is total distance.
The objective is to overcome the total distance and in working
towards this objective there are only two means available:
a) People can be transported to facilities
b) Facilities can be distributed to people
Each method applied in the extreme produces a distinctive kind of
In figure a, the function of transportation is to overcome total
distance between people and facilities.
In figure b, transportation has no function, total distance being
overcome by means of distribution.
Actually, neither transportation nor distribution can do the whole job,
because not all people are mobile and not all facilities can be
People may be place bound because of their age (young and old) or
because of their social role (as women with young children).
Some facilities can’t be distributed because they are underpinned
by natural resources or because, to exist at all, they must exist at a
physical or economic size which prevents indefinite multiplication.
These constraints require the use of both transportation and
distribution to overcome total distance between people and
Part of the distance must be overcome by means of local facilities.
The remaining or residual distance must be overcome by the means
of transportation system.
Accordingly, we combine figures a & b to give a true picture of
In this brief analysis we have identified the major functional parts of
urban structure and given them a meaning in relation to single
The major parts are distributed facility, undistributed facility and
In overcoming distance the first and the third have complementary
More distributed facilities means less residual distance and less
need for transportation capacity;
Fewer distributed means more residual distance and greater need
for transportation capacity;
Practical limits to both concentration and distribution are set by
place bound people and place bound facilities.
Figure c, shows the anatomy of the human settlements conceived
as a system of relating facilities to people.
It also represents the fundamental elements in any plans for the
Certain facilities can be distributed throughout the area in close
physical proximity to their users.
Other facilities can be distributed only in the sense of being made
possible through the transportation system.
URBAN STRUCTURE AND URBAN FORM
Our first objective was to overcome total distance between people
A second objective related to the first, is to reduce residual distance
that is, the distance remaining between people and facilities after
some facilities have been localized.
Residual distance can be reduced by adjustments in the spatial
form of the community.
Form is used here to mean the way the structural components just
described is arranged on the ground the pattern they make.
The effects of this arrangement on, residual distance are depicted in
figure c, d, f.
The obvious effect of the arrangement in figure c is much movement
back and forth between people and undistributed facilities.
Consolidate these facilities at one point and the distance to be
covered will reduce figure d.
It will decrease even further if the consolidated facilities are put at
the centre of the population figure f.
The pursuit of the objective is to reduce residual distance and it
requires that one activity centre in the urban field be privileged with
respect to size and location.
This fact gives functional meaning to the core or metropolis and to
the radial shape of the transportation system serving it.
THE HIERARCHICAL ASPECT OF STRUCTURE
Limits to both concentration and dispersion are set by immobile
persons and by facilities which cannot be distributed.
But not all persons are equally mobile, and not all facilities are fixed
or concentrated in the same degree.
Mobility differs according to age, sex and income etc., whereas
distribution is a matter of economic plant size or of the spatial
scatter of natural resources.
These facts explain the hierarchical tendency of the urban structure:
People must travel different distances to facilities and the facilities
themselves have different service radii.
Also, they account in part for the existence of central places of
several sizes and the corresponding differentiation of the highways
which serve them into major and minor arterial and local roads.
As there is more than one level of community, planning must be
carried out at more than one level.
THE WHOLE AND THE PART
The bringing of people and facilities together creates three urban
Of these, one the distributed facility becomes the basis for a local
organisation of human activities.
The undistributed facility and the transportation element become the
basis for regional organisation.
The existence of these two levels of community is responsible for
the development of a regional as opposed to local area is “home”.
For the regional community the local area a unique geographical
resource to be used for their own purpose.
Where these different viewpoints produce conflicting demands on
the same land, a technical solution is required in the form of a set of
defined land use relationships which permit the simultaneous
expression of both local and regional functions in the same area
with as little friction between them possible.
In this case possibilities are different in different parts of the field.
The structural accommodation is more difficult towards the centre
where the greeted regional paths converge and where regional
facilities come to predominate.
The term urban morphology refers to the physical arrangement or
structure of the town; its patterns of streets, building blocks, and
individual buildings, their different functions, densities and layouts.
A basic approach in studies of urban morphology involves the
mapping and description of patterns of internal land uses as a
preliminary stage in the analysis of the process operating to
produce particular patterns of urban structures.
The models of urban structures are of two kinds: partial and
Partial models are concerned with location of one set of activities,
such as residential such as residential or industrial land use, while
comprehensive models deal with all activities in the urban area and
their inter relationships.
The patterns of urban land use result from a multitude of choices
and decisions about locations. These are made by individual’s
planners, architects, companies and by both local and central
These decisions are influenced predominantly by economic
The figure above shows the offer prices for the three types of
potential land use at different distances from the city centre (O).
Bid prices are based on their ability to derive advantage from
central location in the city.
Thus, at O, retail use, which is most dependent on accessibility, can
outbid other potential users.
However, the offer price curve for retail land use declines more
steeply than that of offices or residences, and the distance between
A and B from the city centre offices can bid for sites most
successfully, while beyond B, towards the urban margin, the offer
prices of residential land use is greater than that of either retail or
Thus, there develops an orderly pattern of urban land uses which is
closely related to rents, which in turn are influenced by land values.
THE LAND VALUE SURFACE
The land values play an important role in determining patterns of
urban land use it is useful to consider the chief influences on land
values in any town.
The land value surface, as the overall pattern of values is termed,
is essentially a reflection of accessibility within the urban area.
Accessibility is greatest at the city centre; it is also greater along
radial and circumferential routes, and especially at their
intersections, than it is away from them.
Some parts of the urban area are better served by transport than
others the land value surface declines more steeply from the centre
in some directions than others.
The characteristics of a typical urban land value surface may be
summarized as follows:
Land values reach a great peak at the city centre and decline by
varying amounts in different directions from the city centre.
Secondary peaks of higher values occur at major traffic
High values occur along the major traffic arteries compared with
values in the area between such routes.
Although the accessibility is the dominant influence, local site
characteristics and other major factors inevitably complicate the
Nevertheless, the general concept of the land value surface
provides a useful background for the study of the various land use
zones in the city.
Population density is a measure of how compact or concentrated a
It takes are of land into account as well as population.
Population Density = population per unit area
(unit area is usually measured in Km2 or miles2)
Sparsely populated = small number of people per unit area ( less
than 100 people / Km2)
Densely Populated = high number of people per unit area (higher
than 100 people / Km2 )
It is important to note that these two classifications and the numeric
cut off of 100 people / Km2 are somewhat arbitrary.
Some books use a middle category moderately populated @ 10-
100 people / Km2
FACTORS AFFECTING POPULATION DENSITY AND
Warmer comfortable climates attract people.
Notice that most people live in a moderate climate region.
Population distribution has changed over time.
No longer are dense populations around primary resources.
Urbanization and the move to the industrial and now the information
ages have changed population distribution.
Coastal regions attracted business and people because of ocean
It was true for initial settlement and is still true today.
Most major cities are located on the coast.
If B does remains similar to A in its space – shape, it will be different
in two other important respects – first in its size and second in its
As with location, changes in the density at which all activities are
carried on follow as a matter of course from changed time –
The general slope of the density gradient depends upon transport
efficiency in substituting more peripheral for more central locations.
A new level of efficiency means a flatter slope, a territory larger
region, a more spread – out centre, and a lower regional density,
assuming of course, that the total population increases less than
proportionally to the increase in area and that there are no unusual
restrictions on space supply.
New time – distances change potential in every part of the region,
throwing in into conflict with actual densities which are past values
The choice is to put things where they belong once more (i.e. in the
right amount), or else, in public interest, deliberately to bear the cost
of not doing so in the form of unrealized value, inflated value, or
MEASURES OF POPULATION DENSITY
Crude population density is a measure of the average numbers of
the individuals per unit area.
As an average figure it suffers all the limitations that this implies.
A crude population density provides no information about the
extreme values within the territory, and comparisons of the density
figures are meaningful only for small areal units such as parishes
and communes, but not for large units such as nations or
A crude density figure alone can never be used as an index of
Because of these limitations, various refinements of crude of crude
population density are sometimes employed.
The densities can be calculated inhabited or cultivated areas only
rather than for gross areas and the latter is called as physiological
or nutritional density.
Conversely, the density of the certain sectors of the population can
be calculated against total area.
The density figures of the industrial or agrarian sections of the
populations and it is referred to as agricultural density.
In the urban area where the high rise blocks of flats invalidated
simple relationships between population and area, here room
density or average number of persons per room, provides an index
widely used by planners and sociologists.
DENSITY OF POPULATIONS AND FLOOR SPACE
Density of population decreases towards periphery of the city at a
diminishing rate with the increase in the distance from the city.
In the vicinity of the city centre, the density drops to zero as the
available floor space is entirely occupied by non – residential uses
particularly by CBD.
The existing stock of buildings (floor space) acts as constraints on
the spatial expansion of the central business use with residential in
area surrounding the city centre (PORTION AB) and mixed land use
explains the sudden depression in the density curve over PORTION
Density of population decreases steeply over PORTION BC
indicating the influence of the proximity to the core in the choice of
Density curve flattens beyond the point c indicating a low density
residential sprawl in peripheral areas.
The gap between the floor space ratio curve and the density curve
indicates the changing intensity of use of floor space for non
In PORTION OB the balance floor space is predominantly occupied
by central business use and retail commercial use while in the
PORTION BC as also in the peripheral areas, it is occupied by
industrial areas, educational areas and other non residential areas.
B A SIC
TER MIN OLOGY
“ LANDUSE CLASSIFICATION & CODING”
The system of urban land use classification is based on the
requirements of the various plans as suggested by UDPFI
The perspective plan which is a policy document, need not show
very many details of a specific land use and may only show the
main use which could be, say, residential or commercial.
In case of a development plan, which is comprehensive plan
indicating use of each parcel of land, there is a need to show more
details of a specific land use.
It has to indicate for the land designated as, say commercial, further
details as to which land is for retail commercial, or for wholesale
trade or go downs.
In the case of layouts of projects of a shopping centre further details
shall be necessary, indicating which block of retail commercial is for,
say, cloth or electronics or vegetables.
Considering this it is suggested that there should be three levels in
land use classification as shown under:
LEVEL I - FOR PERSPECTIVE PLANS
LEVEL II – FOR DEVELOPMENT PLANS
LEVEL III – FOR LAYOUTS OF PROJECTS / SCHEMES
In LEVEL III details are a function of the requirements of a
project/scheme and would vary from project to project, only LEVEL I
and LEVEL II classification is presented.