Urban sprawl assessment using integrated spatial and statistical analysis in the heritage city Varanasi, India

Historical urbanization of India was focused on large cities but Tier-2 cities are expanding at a much faster pace in the 21st century. Unfortunately, a substantial portion of this growth has taken place in a sprawling manner. Urban sprawl and its quantification in Tier-2 cities, despite their rapid growth, has received limited attention. This study aims to address this gap by analysing the urban sprawl of heritage city Varanasi, a fast-growing Tier-2 city and revered as cultural capital of India. Using remote sensing and GIS change detection techniques, the research identifies and quantifies urban sprawl through spatial metrics like Shannon’s Entropy besides Urban Expansion Intensity Index (UEII) for 2003, 2014 and 2023. The analysis evaluates growth patterns across quadrants and concentric zones. By integrating one-way ANOVA with relative Shannon’s Entropy method, the study statistically validates growth differences across core, middle, and outer zones, aiming to comprehend the spatial dynamics of sprawl. The findings reveal substantial expansion in Varanasi from 2014 to 2023, with a 78.94% growth in built-up areas compared to 21.64% growth from 2003 to 2014. Urban sprawl extended in all directions, recording highest changes in the South-east and North-east quadrants. Relative Shannon’s entropy rose from 0.660 in 2003 to 0.924 in 2023 and statistical analysis validates varying extents of sprawling phenomena across the zones in different years. The study contributes methodologically by integrating statistical analysis with spatial metrics, offering a replicable model for concentric cities in India and beyond.