The Urban Heat Island (UHI) effect is a significant concern in today’s rapidly urbanising cities, with exacerbating heatwaves’ impact, urban livelihood, and environmental well-being. This study aims to assess the cooling effect of blue-green spaces in Bhubaneswar, India, and explore their implications for mitigating UHI effects. Satellite images were processed with Google Earth Engine (GEE) to produce information on the blue-green spaces’ land surface temperatures (LST). The Normalised Difference Vegetation Index (NDVI) and Modified Normalised Difference Water Index (MNDWI) were employed to quantify the presence and characteristics of these blue-green spaces. The findings revealed significant spatial variations in the LST, with higher temperatures observed in bare land and built-up areas and lower temperatures in proximity to the blue-green spaces. In addition, a correlation analysis indicated the strong influence of the built-up index (NDBI) on the LST, emphasising the impact of urbanisation on local climate dynamics. The analysis demonstrated the potential of blue-green spaces in reducing surface temperatures and mitigating UHI effects. Based on these results, strategic interventions were proposed, such as increasing the coverage of green spaces, optimising access to water bodies, and integrating water-sensitive design principles into urban planning to enhance the cooling effects and foster a more sustainable and resilient urban environment. This study highlighted the importance of leveraging remote sensing and GEE for urban UHI analyses. It provides valuable insights for policymakers and urban planners to prioritise nature-based solutions for heat mitigation in Bhubaneswar and other similar cities. Future research could delve deeper into a quantitative assessment of the cooling benefits of specific blue-green infrastructure interventions and explore their socio-economic impacts on urban communities.

Rapid urbanisation and changing climate patterns have intensified heat stress in urban areas. Factors such as the Urban Heat Island (UHI) effect, population growth, land use changes, and inadequate green and blue infrastructure contribute to elevated temperatures. The objective of this study is to map heat risks in Delhi using geospatial indicators, showcasing the potential of open-source satellite imagery to enhance Heat Action Plans (HAPs). Utilising Google Earth Engine (GEE) as a robust tool, our methodology integrates satellite imagery and various geospatial data to analyse the drivers and indicators of heat risk based on the IPCC AR5 framework considering Hazard, Exposure and Vulnerability. Comprehensive heat risk maps are generated for Delhi, a city of over 20 million residents experiencing extreme heat and escalating heatwaves. These maps identify areas with increased exposure and vulnerability, providing valuable insights for developing precise mitigation strategies. The outcomes of this research contribute to enhancing Delhi's Heat Action Plan and offer a scalable methodology for assessing heat risks in other cities. The automated GEE script and framework can be readily applied, facilitating the integration of these assessments into HAPs. Moreover, the study emphasises future plans to collaborate with government authorities and disaster management agencies to incorporate on-ground socio-economic data, further refining the heat risk assessment process. Keywords: Heat Risk, Urban Heat Island, Land Surface Temperature, Google Earth Engine