Evaluation of urban expansion and its impact on surface temperature in Beijing, China

This paper reports an investigation into the urban expansion in Beijing during 2004-2009 and its impact on land surface temperature (LST), as well as the relationship between LST and NDVI. LST and landuse/land-cover (LULC) data were extracted from Landsat Thematic Mapper (TM) images acquired on September 8, 2004 and September 22, 2009. The spatial pattern of LST before and after the 2008 Summer Olympic Games in Beijing were compared. The change detection results revealed that the increase of the built-up areas of approximately 139.19km² during 2004 to 2009 and this accounted for approximately 4% of the study area. The spatial pattern of LST was non-symetrical and non-concentric. The high temperature zones clustered towards the south of the central axis and extend to the fifth ring road in 2004, while this situation was relieved in 2009. The correlation analysis indicated that LST values tend to negatively correlate with NDVI in both years with the coefficients of -0.751 and -0.732 correspondingly. Moreover, the overall changes of NDVI accounted for approximately 40% of the LST changes.