Quantifying urban expansion patterns using Shannon's Entropy and Landscape Expansion Index (LEI): A remote sensing study of Bapatla district, Andhra Pradesh, India

Bapatla District. Accelerated urbanisation has resulted in widespread land use/land cover (LULC) changes, disturbing ecological balance and sustainable development. Remote sensing (RS) and Geographic Information System (GIS) have been applied in this research for quantifying urban growth trends using Shannon’s Entropy (SE) and the Landscape Expansion Index (LEI). Multi-temporal satellite imagery (Sentinel – 2A) from 2016 to 2025 was applied for LULC change mapping and assessment of urban sprawl dynamics. Since urban sprawl is a concept that doesn’t have a single definition accepted worldwide, so far it has been effectively depicted in terms of its qualitative, quantitative, and attitudinal landscape patterns (Verma and Garg, 2022). Shannon’s Entropy was utilised in measuring the degree of spatial disorder of urban growth, distinguishing planned and unstructured growth. The Landscape Expansion Index (LEI) also distinguished growth into infill, edge growth, and out-laying and presented evidence of sprawl mechanisms. Results illustrate high rates of expansion of urbanized areas, particularly within peri-urban regions, with entropy values supporting dispersed and fragmented urban growth. LEI analysis showed the dominance of edge expansion, which was a sign of encroachment on agriculture and natural habitats. This paper addresses the urbanisation dynamics of population growth, economic growth, and infrastructure development but with a specific focus on implications in terms of climate resilience, groundwater drawdown, and land use sustainable planning. The findings present policymakers with evidence-based inputs for planning and regulation of urban development, preventing deterioration of the environment, and ensuring equitable regional development in the Bapatla District.