Remote Sensing and GIS Applications for Assessment of Urban Sprawl in Karachi, Pakistan

Over the past 30 years, Land development and consumption have been out of control and expanding out of order, especially to marginal areas of some metropolises in Pakistan. In this research, the dynamic change of urban sprawl and its spatial and temporal characteristics was analyzed for Karachi division, Pakistan. To achieve the goal different image processing techniques were applied i.e., (i) Supervised, (ii) Unsupervised image classification and (iii) Normalized Difference Built-Up Index on Landsat imageries for the years 1991, 2000 and 2013. Unsupervised classification technique was proved to be more effective with an overall agreement of 81%. The study concluded that from 1991-2000, the urbanization in Karachi was increased from 486-729.2 km, whereas from 2000-2013 the urbanization was almost double i.e., 1582.5 km. Apart from the derived results, this study also proved the potentials of remote sensing data and effectiveness of demonstrated/proposed techniques in urban geographic studies.