| Abstract:
Urban expansion and land use changes have a significant impact on land surface temperature (LST). According to the fact that the development of urban is currently one of the most important phenomena in global warming, it is possible to study and measure the temperature of the Earth's surface in urban areas in the shortest possible time with the rapid development of satellite technology. The purpose of this study was to investigate urban expansion and urban heat island (UHI) using remotely sensed data in Shahrekord city. In this study, Ratio vegetation index (RVI) and Normalized difference vegetation index (NDVI), and LST were calculated using multi-spectral and thermal bands of Landsat 7 and 8 satellite images. Land use map was extracted using the maximum-likelihood algorithm in TerrSet software. The overall kappa index was estimated at 0. 82 and 0. 93 for 2003 and 2016, respectively. By comparing two vegetation indexes (RVI and NDVI) and surface temperature during the 13 years (2003 to 2016), it was determined that with urban development, the surface temperature has increased to 2. 210C (from 40. 69 to 42. 90 0C). The results showed that the correlation of NDVI index with the surface temperature map was negative but with positive RVI index. Moreover, these two vegetation indexes, RVI and NDVI, show a more significant relationship with LST in green areas than urban and bare lands. Due to, a significant effect of green areas on regulating LST we recommend that green areas should be expanded in accordance with the urban area expansion.
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