Assessing spatio-temporal patterns of urban growth using geospatial techniques: Kamrup Metropolitan District, Assam, India

Abstract

This study aimed to assess urban growth in the Kamrup Metropolitan District by utilizing geospatial techniques. Additionally, it examined the alignment of observed urban growth patterns in the region with the diffusion-coalescence hypothesis and three-growth-mode theory. To analyze these dynamics, it is essential to assess how land is utilized. Therefore, this study classified land use and land cover, then evaluated urban landscape dynamics through the zone-wise distribution of built-up areas, and computed Shannon’s entropy alongside landscape metrics such as Number of Patches (NP), Largest Patch Index (LPI), Edge Density (ED), Mean Euclidean Nearest Neighbor Distance (ENN_MN), Contagion (CONTAG), and Shannon’s Diversity Index (SHDI). Furthermore, we delineated urban growth typologies using the Landscape Expansion Index (LEI) and compared the results of each technique with the established urban growth theories. Results indicated that the built-up area increased from 40.97 km² in 1990 to 183.86 km² by 2024, with burgeoning sprawl predominantly occurring in peripheral buffer zones further away from the urban core. This revealed a dual growth trajectory: the urban core demonstrated coalescence through infilling, while peripheral regions experienced urban sprawl, marked by increased dispersion and outlying growth as indicated by a Shannon entropy value exceeding 0.5. Landscape metrics further elucidated these dynamics with increases in ENN_MN and LPI reflecting clustering in core areas, whereas increases in NP, LPI, ED, SHDI, and decreased in CONTAG suggesting dispersion in peripheral areas. Thus, diffusion and coalescence occurred simultaneously. These results provide empirical insights into urban growth patterns to aid policymakers in urban planning.