Assessment of the impacts of urbanization on enhancing urban green space inequality and thermal condition of New Town, Kolkata, India

Abstract

The exponential growth of population over the past few decades has drastically changed the landscape, significantly impacting green space (GS) and ecosystem resilience. The urban expansion engulfs the GS and exerts a strong influence on land surface temperature (LST). This study aims to investigate the impact of urban expansion on GS loss and LST over the last 30 years using advanced GIS and RS techniques. The finding indicates a dramatic increase in built-up areas, from 0.01 km² to 25.14 km², while GS decreased 16.31% over the last 30 years, contributing to a LST rise from 28.35 °C to 44.67 °C. The land use dynamic degree index (LUDDI) highlights a haphazard urban development, with change intensity index (CII) showed an intensified development trend (1.55). Consequently, Per-Capita GS (PCGS_city) alarmingly declined from 8.87 m²/person in 2004 to 1.41 m²/person in 2024, aligning with the Gini index of inequality result. The findings reveal a positive correlation between GS loss and LST. The Green Space Land Index (GS_LandIndex) showing 9 mouzas fallen under < 20% GS in New Town Action areas 1 and 2; this number is in an increasing trend, as a result of drastic LST change observed in the last decade, shifting from 32.82 °C to 44.67 °C, which exceeds the global typical UHI threshold and is directly related to global warming. Thus, the study portrays the urgent needs of GS management strategies, climate hazard management, and pollution control to ensure human health and urban sustainability in New Town, with broader implication for rapidly growing cities worldwide.