Assessment of urban growth using Shannon’s Entropy Index: A case study of Chennai, Detroit of India

Abstract

The Remote Sensing (R/ S) and Geographical Information System (GIS) play a vital role to evaluate and study the urban expansion pattern. In this study, the Chennai city was selected to perform the urban sprawl study. Five different periods of satellite imageries for the time elapsed between 1994 and 2016 were used. The main aim of this paper was to identify the urban sprawl of Chennai as a patterning process. The extended areas of urban in the period of 1994, 2001, 2006, 2011 and 2016 were extracted by the sub-pixel classification method from the satellite imageries. Furthermore, Shannon’s entropy index was used for assessing urban expansion. The findings of this study proved that Chennai city has sprawled by urban expansion during the period between 1994 and 2016. Likewise, the dispersion rate of urban sprawl for the periods of 1994, 2001, 2006, 2011 and 2016 were 0.671, 0.679, 0.688, 0.693 and 0.695 respectively. Consequently, this uncontrolled dispersed urban development had resulted in the study area losses their green space.

Assessment of urban development pattern and urban sprawl using Shannon’s entropy: A case study of Konya (Turkey)

“…To understand the urban growth better, built-up area is calculated for every period reviewed (Shenbagaraj et al, 2019). Shannon's entropy is used to measure the spatial concentration or dispersion degree of geographical variables within "n" spatial units / areas.…”

“…Usually, the literature about urban sprawl refers to the high spatial growth in cities. The studies on urban sprawl in the literature review the measurement of the sprawl, determining the parameters, (Ashkenazi, 2008;Çavuş & Başaran Uysal, 2018;Ewing et al, 2002;Frenkel & Ashkenazi, 2008;Galster et al, 2001;Hasse & Lathrop, 2003;Öztürk, 2017 a-b;Yeh & Li, 2001;Shenbagaraj et al, 2019;Sudhira et al, 2004); reasons and impacts regarding the measurements, and (potential) policy measures, (Buitelaar & Leinfelder, 2020;Ewing, 1997;Ewing et al, 2002;Galster et al, 2001;Torrens &Alberti, 2000) or a combination of these. These studies generally produced different sprawl indexes and were conducted in this regard (Frenkel & Ashkenazi, 2008;Galster et al, 2001).…”

“…Therefore, the topic of monitoring urban expansion and settlement catches more attention (Shenbagaraj et al, 2019). Studies on measuring the stylistic characteristic of sprawl and assessing the urban development have accelerated in recent years (Öztürk, 2017 a-b;Shenbagaraj et al, 2019;Terzi & Bölen, 2010). In addition to qualitative assessments, quantitative examinations and mathematical and mixed fuzzy analysis methods are commonly used to measure the urban and stylistic characteristics.…”

“…In addition to qualitative assessments, quantitative examinations and mathematical and mixed fuzzy analysis methods are commonly used to measure the urban and stylistic characteristics. Accordingly, shape index as well as contagion index, Shannon's entropy index (Bhatta, 2012;Öztürk, 2017 a-b;Shenbagaraj et al, 2019cited by Garg & Sharma, 2018Sudhira et al, 2004;Yeh & Li, 2001), Holderness method (Mohammadi et al, 2012;Ghorbani & Farokhisomeh, 2015) Geographical Information System (GIS) and fractal analysis have captured great attention in the studies on urban sprawl (Bhatta, 2012;Öztürk, 2017 a-b;Shenbagaraj et al, 2019cited by Garg & Sharma, 2018Steurer & Bayr, 2020;Sudhira et al, 2004;Terzi & Bölen, 2010;Yeh & Li, 2001).…”