Monitoring the Relationship Between the Land Surface Temperature Change and Urban Growth in Beijing, China

Abstract

This paper attempted to evaluate the effects of urban growth on the land surface temperature (LST) in Beijing, China. Firstly, the multi-temporal land use types were derived based on the images of Landsat 5 TM and Landsat 7 ETM+ from 1996 to 2010, and two types of land use change trajectories (existing urban trajectory and urban growth trajectory) were also established to category the land transformation type under urbanization. Then the algorithm developed by the Landsat project Science Office was adopted to retrieve LST, in which the digital number (DN) of Band6 was converted to the spectral radiance, followed by being converted to the brightness temperature under the assumption of unity emissivity, and corrected for emissivity (e) to obtain the natural surface temperature. Finally, to evaluate the effects of urban growth on the LST change, two indices of deviation degree and LST change contribution were built and calculated for each trajectory. The results demonstrated that the average deviation degree of urban growth trajectories was much greater than that of the existing urban trajectory, which presented a more violent LST change. However, the effects of urban growth on the LST change of the study area were very limited because the smaller areas of the urban growth trajectories would generate a limited LST change contributions. The results could not only provide a new way and methodology to assess the relationship between urban growth and the LST change, but also support the management and planning in the urban area.