Computing the Urban Sprawl Dynamics through Fractal Geometry

Abstract

Urban sprawl has become a very magnificent topic throughout the world since last decade.
Various techniques, methodologies and quantitative approaches are based to measure urban
sprawl in previous researches. In this research a different idea of fractal analysis is
introduced to analyze the urban sprawl. In addition density gradient and sprawl index
techniques have also been used to characterize the urban sprawl in Karachi. In this study, we
have discussed the urban sprawl of Karachi from its first census (1951) to 2012. Massive
flight of the population is recorded between 1981 and 1998 to the periphery of city Karachi.
As a result central population density decreased at rapid space and population density
gradient exhibits a gentle slope. Overall population density of Karachi constantly increases
from 1951 to 1998 but it decreases in 2012 because large rural lands were converted into
urbanized lands during 2002 to 2012. For the same six time periods, urban form of Karachi
is also quantified through fractal analysis in the context of urban sprawl dynamics. Our
results suggest that the fractal dimension of urban form is proportional to the urban sprawl
index for the concentrated urban growth patterns. We have also tried investigating sprawl
phenomena theoretically further, we have probed the causes and impacts of urban sprawl in
Karachi in a given time periods.