The Effects of Vegetation & Bare Land on Thermal Characteristics: A Case Study of Three Indian Metropolitan Areas

Urban expansion in India’s metropolitan regions has led to significant alterations in land surface composition, which directly affect local thermal environments. Vegetation loss and the emergence of bare land surfaces are increasingly recognized as key contributors to urban heat, yet comparative, multi-city studies addressing their combined effects remain scarce. This study analyzes the influence of vegetation and bare land on land surface temperature (LST) across three major Indian cities—Delhi, Lucknow, and Ahmedabad in 2023. Satellite imagery was used to extract Normalized Difference Vegetation Index (NDVI), Normalized Difference Bareness Index (NDBaI), and LST values. Statistical correlation and spatial analysis techniques were applied to evaluate thermal variations across land cover types. NDVI was negatively correlated with LST (r = −0.68 to −0.81), indicating the cooling role of vegetation, whereas NDBaI showed a positive correlation with LST (r = 0.59 to 0.74), highlighting the warming effect of bare surfaces. Delhi exhibited the highest maximum LST (47.45 °C), while Lucknow recorded the highest minimum (38.63 °C). Across all cities and timeframes, vegetated areas consistently showed lower surface temperatures compared to bare or built-up regions. The findings emphasize the importance of vegetation in reducing urban heat and the thermal risk posed by increasing bare land. Strengthening green infrastructure and minimizing exposed soil in urban areas can serve as effective strategies for enhancing thermal comfort and climate resilience in Indian cities.