Assessing Kolkata's Urban Sprawl

Urban sprawl has emerged as a critical challenge in the context of developing nations. The KMDA region has undergone a remarkable spatial transformation over the past three decades. This study aims to assess, quantify, and analyze the spatial and temporal patterns of urban sprawl in the KMDA region from 1991 to 2021 using multi-temporal satellite data and advanced geospatial techniques. The analysis employs Landsat Thematic Mapper and OLI-TIRS imagery from 1991, 2001, 2011, and 2021 to derive LULC classifications using the supervised Maximum Likelihood method. To evaluate the spatial dispersion of urban expansion, Shannon's entropy model was employed, revealing entropy values ranging from 2.33 in 1991 to 2.95 in 2011, signifying increasing urban sprawl and spatial diffusion. The findings reveal an outward migration of the urban core from ~ 6 km in 1991 to nearly 14 km in 2021. This study will contribute to a deeper understanding of urbanization processes in rapidly growing South Asian cities.