Monitoring of land surface albedo and its impact on land surface temperature (LST) using time series of remote sensing data

Abstract

Urbanization and urban population growth are increasing every day across the world. The replacement of natural surfaces with artificial surfaces such as bitumen, asphalt, and cement reduces albedo, increases the land surface temperature (LST), and contributes to creating urban heat islands (UHI). In this study, Landsat satellite time-series images were used to produce land use/land cover (LULC) and calculate albedo, LST, and normalized differential vegetation index (NDVI) in the 1985–2018 period of Tabriz. The results demonstrated an over 170% increase in the area of impervious surfaces. Monitoring of albedo and LST in the 1996–2018 period showed that reflective surfaces could reduce the mean temperature of impervious surfaces in the entire city by 4.42 °C and increase the mean albedo by 0.0647. Meanwhile, LST was decreased by 7.97 °C and albedo was increased by 0.1633 in densely populated urban areas. The Pearson correlation coefficient between LST and albedo in the impervious surface class was −0.6 for the entire city, which is higher than the correlation between NDVI and LST parameters in the vegetation class. Therefore, reflective surfaces can reduce the surface temperature more efficiently than vegetation. It is worth mentioning that this correlation reaches up to −0.8 in urban districts. The research findings showed that urban growth and the increasing area of impervious surfaces could create urban cold islands instead of urban heat islands if reflective surfaces are used in the rooftops.