Dynamics of land surface temperature: Insights into vegetation, elevation, and air pollution in Bengaluru

Abstract

Bengaluru, among the five fastest-growing cities of India, is facing the challenge of urban heat islands (UHI) and temperature variations across its landscape. Monitoring the temperature fluctuations is crucial for understanding the city's microclimate and the impact of urbanization on its environment. Land Surface Temperature (LST) is a significant metric for this purpose. The present study examined the relationship of LST with vegetation, elevation, and air pollutants during the summer and winter seasons for 4-years (2019–2022). Air pollutants and weather parameters data from air quality monitoring stations was used. The study found negative relationship of LST with NDVI and Digital Elevation Model (DEM) during both seasons. The relationship between LST and individual air pollutants was variable during the summer and winter seasons and R2 ranged between 0.52 and 0.79. The relationship became stronger (R2 between 0.69 and 0.82 during summer and R2 between 0.74 and 0.80 during winter season) when all the parameters were considered simultaneously. The result from the Taguchi method showed that different air pollutants had variable impact over change in LST and the order of their effect was found to be PM2.5 > SO2 > O3 > CO > NO2. The results indicate that O3 (summer) and PM2.5 (winter) were the major contributors to rising LST. The present study has applications in future scientific research as well as it can be utilized to integrate mitigation strategies for increasing temperatures.