Effects of COVID-19 Lockdown on LST, NDVI, LULC, and UHI: Dehiwala-Mount Lavinia Case Study

The COVID-19 pandemic has had a profound global impact since its outbreak in late 2019. To curb the spread of the virus, measures were implemented to control its transmission, such as reducing human activities, shutting down industries, minimizing transportation, and practicing social distancing. A case study focused on the Dehiwala-Mount Lavinia suburb analyzed various environmental indicators during normal working days in April 2019 and the lockdown phase in April 2020. Landsat 8 (TIRS/OLI) images, processed with ArcMap 10.8.2 software, were used to examine the impact of the lockdown on environmental conditions by comparing Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), Land Use/Land Cover (LULC), and Urban Heat Island (UHI). The results revealed a decrease in LST and an increase in NDVI during the lockdown. The analysis of LULC showed increased vegetation growth near the Aththidiya wetland area. A relatively cooler UHI was observed in 2020 compared to the year 2019. These findings underscore the influence of human activities on UHI and highlight the importance of urban planning and mitigation strategies to address UHI effects on local climates.