Urban Heat and Vegetation Dynamics in Rajshahi City: A Google Earth Engine- Based Analysis from 2005 to 2024

Understanding the spatiotemporal dynamics of urban surface temperature and vegetation health is vital for sustainable urban planning, particularly in rapidly developing cities such as Rajshahi. This study analyzes long-term changes in Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), Health Vegetation Index (HVI), Urban Heat Island (UHI), and Urban Thermal Field Variance Index (UTFVI) within Rajshahi City Corporation over 20 years, from 2005 to 2024. Multitemporal Landsat imagery and the cloud-based Google Earth Engine (GEE) platform were employed to examine three key time points 2005, 2015, and 2024, and assess the impacts of urban expansion and vegetation loss on the urban thermal environment. Results reveal a consistent increase in both LST and UHI intensity. In 2005, LST ranged from 23.49°C to 38.57°C, rising to 24.21°C to 41.34°C by 2024. Correspondingly, UHI values intensified from a range of –1.063 to 2.458 in 2005 to –3.79 to 4.97 in 2024. NDVI and HVI values declined in the urban core, indicating vegetation degradation, while UTFVI patterns reflected increasing ecological thermal stress, especially in densely built-up areas. Spatial analyses confirmed that impervious surfaces are associated with higher heat stress, whereas vegetated zones help mitigate thermal impact. The integration of remote sensing indices with GEE’s processing capabilities offers an efficient and scalable approach for monitoring urban climate dynamics. These findings provide actionable insights for urban planners and policymakers to implement nature-based solutions, improve thermal comfort, and enhance ecological resilience in Rajshahi’s evolving urban landscape.