Monitoring and Modelling of Urban Sprawl Using Geospatial Techniques—A Case Study of Shimla City, India

Abstract

Urban Sprawl, a burning global phenomenon, refers to that extent of city or urbanisation, which may driven by industrialisation, population growth, settlement on the periphery of the city and large-scale migration. India, with population of over one billion, which is one-sixth of the world’s total population, phenomenon of Urban Sprawl is affecting its natural resources like never before. This results in multiple problems such as unmanageable transportation, unemployment which results in poverty, illegal housing colonies, slums, etc. This study illustrates the use of Geospatial and Statistical Techniques to highlight the extent of Urban Sprawl in Shimla Municipal Corporation, Himachal Pradesh, India; at a detailed level. In the present work, four temporal satellite images of Landsat Thematic Mapper have been used over a period of nearly two decades (i.e. 1991–2011). Landsat imageries of two time periods (Landsat Thematic Mapper (TM) of 1991 and 2011; and ETM+ (Enhanced Thematic Mapper) 2001), were used and quantified for studying the decadal change in land use/land cover. Supervised classification methods have been employed using Support Vector Machine in ENVI 5.0 and ERDAS 2014. The study area is categorized into five different classes, viz. water bodies, forest area, built-up area, agriculture and open space. The results indicate that built-up area is the major land use in study area. During the period 1991–2011, the area under built-up land has increased by 529.65 ha (26.48)% due to construction of new buildings on forest land, agricultural land and open spaces. As a result, the area under vegetation (forest), open space and water bodies decreased by −361.71 ha (−18 09%), −178.02 ha (−8.90%), 0.36 ha (0.02%) respectively. Urban built-up density was calculated in percentage (%) for 25 wards of the city for 1991, 2001 and 2011. Depending on the density levels, it categorized as low, medium and high density. The process of urban expansion in the Shimla City during 1991, 2001 and 2011 are further studied by examining a distance decay concept from a major road. The study also highlights the nature, rate and location of change; and the importance of digital change detection techniques in land use planning for sustainable growth of the study area. The Shannon’s Entropy Index and Landscape Metrics have been computed in order to quantify the urban growth using built-up area as a spatial unit. Further, Stepwise Regression techniques were used to explore the relationship between the urban growth and its contributory factors. Further, Stepwise Regression was used to study the impact of Independent Variables (population density, female literacy rate, road density, total workers, sex ratio, α-population, number of HH, β-population) and Dependent Variables (percentage of built-Up area) factors on urban growth. The result shows that the growing population triggers the increase in built-up area in study area. This study also demonstrates the potentials of geospatial data in mapping, measuring and modelling the urban sprawl, which could be helpful to decision makers to form/make particular decision support system for sustainable growth of hilly urban areas or in making Smart City planning.