Physical Density and Urban Sprawl: A Case of Dhaka City - KTH

CHAPTER 2
THEORY OF THE CONCEPTUAL FRAMEWORK
The purpose of this chapter is to present the theoretical and conceptual frame work that is
considered and reflected upon, and which will guide this study. The focus is on the concepts
that centre on analysis of physical densities and spatial qualities of housing blocks, urban
sprawl, and informal settlements. The concepts employed are discussed in relation with the
theories. It is necessary to identify relevant variables that can be used in the analysis of
physical densities and spatial qualities of housing blocks, since the objectives of the study is
to analyze physical densities and spatial qualities of urban housing block.
2.1 Urban Sprawl
Urban sprawl is one of the contemporary issues of today’s world. It is very difficult to find a
common definition to urban sprawl. But the most common phenomenon of urban sprawl is
expansion of urban area without efficient use of land. According to Vestbro
“Urban sprawl may be defined as the phenomenon when urban areas expand
without procedures for efficient land use. It is typically expressed in allocating
ample space to roads and parking areas, to buffer zones and impediments
(leftover spaces) between built-up areas, and in residential developments with low
densities. Such planning procedures lead to encroachment of valuable
agricultural land, to long travel distances between residences and work places, to
high infrastructural costs because of long lines of roads, pipes, drainage ditches
etc per house, and to a lack of urban qualities. Combined with the construction of
external shopping malls urban sprawl also leads to the deterioration of local
services and to segregation between those who have cars and those who don’t”
(Vestbro, 2004).
In the city with sprawl, the residential area is developed with low physical densities. As a
result there is an encroachment of development to the valuable agricultural land or other open
spaces. The area of the city increases horizontally for that encroachment. The cost of
infrastructures and traveling increase due to the development of long lines of roads, pipes,
drainage etc, and so, there is a close relationship between low density residential
development and urban sprawl. This present study will try to explore that relationship by
analyzing the housing densities of Dhaka.
According to Galster, et. el. (2001) “sprawl can be observed in different circumstances and
conditions; it is possible that there can be different types of sprawl, which consist of
combinations of different variables”. They propose different dimensions of land use and
when those low values are found in an area, then it signifies urban sprawl environments.
Density is one of the vital dimensions among them. In spite of the mixed land use
characteristics with medium or high physical density in terms of FAR and percentage of land
coverage, the problems regarding to sprawl can be seen in a lot of cities all over the world
due to the development of low dense informal housing blocks in the centre or periphery of the
city. The physical density has been calculated from the FAR and percentage of land covered
by buildings in the specific block which has been described in detail in the previous chapter.
Downs (1999) notes several causes of urban sprawl. Unlimited outward extensions of
development as well as low-density residential and commercial settlements are the prime
causes among them. This writer also notes some effects of sprawl which comprise of air
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