Quantification of Surface Urban Heat Island Intensity Using MODIS Satellite Imagery in Different Indian Cities

Quantification of Surface Urban Heat Island Intensity (SUHII) with urbanization needs to be explored for varying land covers. The two parameters (area showing SUHI effect and urban-rural temperature difference) are equally important for the quantification of SUHII. In this study, SUHII(a) was calculated using only area contribution, SUHII(b) was calculated using only urban-rural temperature difference and SUHII(c) represents a modified algorithm using both factors contributing to the SUHI effect in combined form. Therefore, three different methods were used for the quantification of SUHII for winter, summer and post-monsoon seasons of years 2001, 2007, 2013 and 2019 in three cities i.e. Varanasi, Bangalore and Bikaner using MODIS Land Surface Temperature images. SUHII(a) increased from the year 2001 to 2019 for cities with small variation in seasons. The rate of change of SUHII(b) showed clear variation for different seasons in three cities. SUHII(c) showed a greater slope for winter and lower for the post-monsoon season in Varanasi which was similar to the variation of SUHII(a) and SUHII(b) in the city. In Bangalore, the slope for SUHII(c) was higher in the post-monsoon season and lower in summer because the slope of SUHII(b) was found quite lower for summer. The slope of SUHII(c) was lower in post-monsoon and higher in summer for Bikaner city. The slope of SUHII(b) showed a negative value with greater magnitude in post-monsoon. This results in a lower rate of increasing SUHII(c) in post-monsoon as compared to other seasons in Bikaner. Therefore, the calculation of SUHII(c) can provide future insight to understand the effect of urbanization on the thermal environment and develop mitigation strategies.