Spatiotemporal evolution of surface urban heat island intensity in Vellore: A three-epoch (2005–2015–2024) landsat-based assessment

Rapid urbanization and infrastructure development are contributing to increases in the Urban Heat Island (UHI) phenomenon, especially in hot-humid areas. Urban thermal environments have undergone dramatic alterations due to reduced vegetation cover and increased anthropogenic heat emissions. This study integrates urban morphology with Local Climate Zone (LCZ) classification to investigate the spatiotemporal comparison of Surface Urban Heat Island (SUHI) in Vellore, India, a rapidly growing secondary city. Multi-temporal Landsat data (2005, 2015, 2024) were used to derive Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI), while SSTA (Standardised Surface Thermal Anomaly) was compared between built-up LCZs and the LCZ-D rural reference class. The research shows that high-density built-up zones exhibit significantly higher LST and SUHI intensities than their vegetated counterparts. A sharp increase in both spatial expansion and intensification over time corresponded to growing urban densification of hot spots. Results are consistent with shift from vegetation-driven to morphology associated thermal behaviors, illustrating the enhanced importance of urban form in heat distribution. Planning based on LCZ, such as a move to open low-rise and mid-rise forms, can also improve ventilation and reduce accumulation of heat, underpinning climate-responsive urban development in line with Sustainable Development Goals 11 and 13.