How Urban Ecosystems Metabolize Heat: Green Processes Regulating Thermal Equilibrium in Bhopal City, India for green environmental sustainability

Rapid urbanization and climate change are intensifying thermal stress across cities, particularly in rapidly expanding urban centers of the Global South. This study develops an urban thermal metabolism framework for Bhopal City, India, to examine the interactions among thermal accumulation, urban morphology, and nature-based cooling processes. Annual datasets of Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), Modified Normalized Difference Water Index (MNDWI), Cooling Potential Index (CPI), and World Settlement Footprint 3D (WSF3D) were integrated for 2024. Results reveal pronounced thermal heterogeneity, with LST ranging from 23.40°C to 44.11°C (mean = 33.89°C; SD = 3.86°C). Areas characterized by higher building volumes (mean = 7,527.99 m³) exhibited greater thermal accumulation, whereas green and blue infrastructure contributed to localized cooling, reflected by a mean CPI of 0.515. A statistical consistency assessment comparing satellite-derived LST with NASA POWER air temperature showed an air-temperature range of 16.21–35.24°C (mean = 25.18°C; SD = 5.98°C) and an LST range of 23.40–44.11°C, with a mean thermal difference of 8.71°C. LST exhibited a slightly wider absolute temperature range (20.71°C) than air temperature (19.03°C), while its coefficient of variation was lower (11.39% versus 23.75%), reflecting the distinct thermal characteristics of land-surface and near-surface atmospheric temperatures. The findings demonstrate that urban thermal equilibrium in Bhopal is governed by the dynamic interplay between built-up intensity and ecosystem-mediated cooling processes. The study contributes a transferable urban thermal metabolism framework for understanding urban heat regulation and provides evidence to support green infrastructure planning, climate adaptation, and the development of environmentally sustainable and thermally resilient cities.