Impact of Urban Expansion on Urban Heat: A Case Study of Greater London

Urban expansion in several cities has been linked with significant impacts on land surface temperature (LST). In this study, we investigate the impacts of urban expansion on Greater London within the last two decades (2000–2022). Landsat TRM and OLI_TIRS imageries for the years (2000, 2013, and 2022) which were obtained from the USGS Earth Explorer’s website were used for the study. Using this dataset, we conduct supervised maximum likelihood classification (LULC), LST, and Normalized Differentiated Vegetation Index (NDVI) analyses. The study revealed a significant 38.5% rise in developed areas, correlating with an increase in Land Surface Temperature (LST). Specifically, Greater London experienced a 19.3% uptick in average surface temperature from 2013 to 2022, indicating a rapid recent escalation. Additionally, there was a substantial 16.1% increase in average surface temperature from 2000 to 2022, coupled with a 2.6% decrease from 2000 to 2013. These findings underscore a heightened temperature trend in recent years. Examination of the Normalized Differentiated Vegetation Index (NDVI) for London Boroughs across 2000, 2013, and 2022 unveiled notable shifts in land use and vegetation cover. The observed moderate to strong positive correlation between LST and NDVI, with R-squared values of 0.476 (2000), 0.531 (2013), and 0.621 (2022), indicates that NDVI explains 73–79% of LST variation. Findings from the study suggest an increase in land use patterns and urban expansion in London Boroughs within the last two decades. These changes present great danger to the urban environment, air quality, and LST in Greater London. Based on the results of this study, we recommended incorporation of sustainable urban planning, preserve water bodies, and strategically plan expansion with heat-reflective materials to mitigate heat island effects and enhance environmental resilience in Greater London.