Response of soil moisture and vegetation conditions in seasonal variation of land surface temperature and surface urban heat island intensity in sub-tropical semi-arid cities

The cities of arid and semi-arid regions have distinctive landscape patterns and large-scale variations in soil moisture and vegetation cover which causes significant variations in land surface temperature (LST) and surface urban heat island intensity (SUHII) pattern. Therefore, the study aims to analyse the seasonal and spatial variation in LST and SUHII in the eight semi-arid cities of India in response to soil moisture and vegetation conditions. LST was retrieved from the thermal bands of Landsat data and then SUHII was calculated. The global Moran’s I was used to analysis the spatial pattern of SUHII. The result shows that the mean SUHII was higher during spring and summer seasons to a tune of 0.2 to 1.0 °C in comparison to the winter and autumn season. SUHII zones exhibit seasonal variation in coverage, with high and very high zones increasing during spring and summer, while low and very low zones increase during autumn and winter. Furthermore, the highest LST was noticed in outskirt areas of the selected cities. The regression coefficient shows that soil moisture is closely associated with SUHII, while there is a weak association between vegetation condition and SUHII. This indicates that soil moisture has a higher impact on SUHII than vegetation condition in semi-arid environment. Global Moran’s I showed that the SUHII had a clustered distribution pattern across all cities. The outcome of this study may provide useful insight for the urban planners in SUHII mitigation in the selected cities as well as in other semi-arid cities of the world with similar geographical conditions.