Impact of vegetation indices and urban surface characteristics on land surface temperature changes (Case study: Sanandaj city)

Land surface temperature (LST) is an important factor in global warming studies. Therefore, considering its negative effects on human life, it is very important to study this phenomenon. The aim of this study was to investigate the effects of vegetation indices and surface characteristics of Sanandaj city on land surface temperature changes. For this purpose, the land surface temperature was calculated in ArcGIS and vegetation indices and the surface Sanandaj city were derived from Landsat images in ENVI software. The results of regression analysis and correlation of LST with synoptic station data were 0.45 and 0.20 respectively, which shows a positive relationship. The results of the overall accuracy and the indices shows that the correlation analysis the precise indices (enhanced buildup and bareness index, index-based built up the index, normalized difference built up the index, urban index), positive relationship and low precision indices (normalized difference bareness index, new built up the index, normalized difference water index, modified normalized difference water index) have the opposite correlation with land surface temperature. The results of the temperature situation in the vegetation classes indicate that the high temperature was observed in the low vegetation classes in the early summer of 1988, 1999, 2008, 2012, 2014 and 2015, and the lowest temperature in dense vegetation classes at the end of spring, 1989, 1993, 2000, 2007, 2010 and 2016. Therefore, the reduction of vegetation and growth of built-up areas has an important role in increasing the land surface temperature, and spectral indices to extract buildup areas from satellite images can provide acceptable results.