The Influence of Vegetation and Surface Changes on Urban Heat Island Dynamics

Urban Heat Islands (UHIs) exacerbate the challenges of rising temperatures in urban areas, increasing heat stress and thermal discomfort for urban dwellers. This study focuses on Bhubaneswar, a city in eastern India experiencing significant recent urbanisation, to analyse the effectiveness of greening efforts on dynamics of UHIs. For that, Land Surface Temperature (LST) was derived from Landsat 8 and 9 data spanning 2013 to 2024 to evaluate UHI pockets, persistence UHI and reduced UHI areas along with the Normalized Difference Vegetation Index (NDVI) and Bare Soil Index (BSI), to investigate the relationship between vegetation cover, bare surfaces, and influence on UHI dynamics. The analysis identified persistence UHI in industrial zones, including the airport and bare land areas. Conversely, newly formed UHI pockets emerged along national highways and dense built-up areas. The study also identified reduced UHI areas, regions that exhibited intense UHI effects in earlier years but showed no UHI presence by later years. These areas show the positive impact of greening initiatives and surface changes over the past decade. NDVI analysis revealed a significant increase in vegetation in reduced UHI areas, indicating the positive impact of initiatives. In contrast, persistent UHI areas, exhibited lower NDVI values, underscoring the lack of vegetation and its role in sustaining high LSTs. BSI analysis further complemented these findings, showing a notable reduction in bare surfaces within reduced UHI areas compared to persistent UHI zones. The results highlight the critical role of vegetation in moderating UHI effects. This study underscores the importance of integrating green infrastructure into urban planning to address the growing UHI effects in cities. The results highlight the need to expand greening efforts to effectively manage UHI effects in urban areas.