An Analytical Investigation of Urban Expansion Patterns in the Kolkata Metropolitan Development Authority (KMDA) Region Using Geoinformatics

Urban expansion has been significant and rapid over the last 30 years, with the outward growth of the Kolkata Metropolitan Area (KMA). Much of this growth has followed a lowdensity, disparate development pattern, commonly known as urban sprawl. This study aims to examine the spatial expansion pattern in the Kolkata Metropolitan Development Area (KMDA) between 1990 and 2020 through the application of advanced geoinformatics tools and spatial metrics. We analyzed Landsat Satellite images from 1990, 2000, 2010, and 2020 to evaluate urban areas, including their extent and trends. Patterns of directional expansion, assessed using standard deviation ellipses and wedge analysis, showed a clear north-to-south axis of growth in the study area. The expansion of urbanization by 2020 was therefore more concentrated in the south-western region. Urban growth rates were measured using the Annual Urban Expansion Rate (AUER), Urban Expansion Intensity Index (UEII), and Landscape Expansion Index (LEI). The urban land cover of the study area increased by 446.71 km2 during the study period. The highest growth rate was from 1990 to 2000 (5.42%), followed by a decline in subsequent decades. LEI analysis revealed edge expansion as the prevalent growth type, which is a typical feature of urban sprawl. A mixture of infilling and peripheral growth patterns points to the processes of urban diffusion and clustering. Results for the Department of Labrador were obtained using the Area-Weighted Mean Patch Fractal Dimension (AWMPFD), which classified the urban spatial patterns into four types: major core, secondary core, suburban fringe, and dispersed settlements. Central aggregation and peripheral fragmentation are related straightforwardly. Multiple correspondence analysis (MCA) further confirmed this spatial distribution pattern, which has valuable implications for both resource managers and urban planners.