Assessing the intensity of land surface temperature in Thiruvarur district (India).

Abstract

Nature gives way to the emergence of concrete jungles as cities grow around them. The majority of these concrete masses are highly reflective, changing the surrounding temperature. Hence, urbanized regions often have higher average temperatures than their surrounding rural areas. This phenomenon is termed Urban Heat Island (UHI). The intensity of UHI depends up on Land Surface Temperature (LST). This paper intends to study the intensity of LST in the Thiruvarur district and its correlation with Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI) using Landsat 8 Imageries (OLI & TIRS) of January 2018. To calculate the LST, we used the mono-window algorithm. The result shows that LST intensity varies from 20.68°C to 32.3°C, with the maximum being in built-up areas and the minimum being in vegetation areas and water bodies. The Pearson regression shows that there is a negative correlation (r = -0.925, P < 0.5) between LST & NDVI and a positive correlation (r = 0.925, P < 0.5) between LST and NDBI. The strong positive correlation of NDBI confirms the influence of urbanization on Surface Urban Heat Island (SUHI). The negative correlation between LST and NDVI shows that green covers can mitigate it. Hence, this study conclusively demonstrates that urbanization can raise temperatures, showing that sustainable development in cities is essential for sustainable growth.