Evaluating urban heat island to achieve sustainable development goals: A case study of Tiruchirappalli city, India

Tiruchirappalli City the fourth largest municipal corporation in Tamilnadu, India is witnessing accelerated urban growth. The city has exacerbated the microclimate indicating a significant increase in land surface temperature. The study aims to establish the differentiation of land surface temperature of city between 2001, 2011, and 2021 of summer months using Landsat images to examine the effects of urban heat island. The results shows that the temperature ranged from 31.23°C to 37.45°C between 2011 and 2021. The assessed land surface temperature (LST) is correlated and the result shows a positive correlation between the LST-normalised difference built-up index (NDBI) and a negative correlation between the LST-normalised difference vegetation index (NDVI) and a weak correlation between LST-BSI and LST-MNDWI of summer months examined. Further, the urban thermal field variance index (UTFVI) of the city is analysed. The thermal condition of the city during April has significantly changed from 5.14 % of area in 2001 to 12.19 % of area in 2021 (UTFVI >0.020, Strongest) of worst ecological valuation index. The selected city is experiencing major thermal conditions (UTFVI 0.010–0.015) of ecological evaluation index from bad to worst. This study will help mitigate the urban heat island effect and promote sustainable development for rapid urbanization.