The spatial characteristic of land surface temperature in Beijing area

Thermal-infrared images of Landsat Enhanced Thematic Mapper Plus (ETM+) in 1999 was used to retrieve the land surface temperature (LST) of urban and surrounding area of Beijing, The urban heat island ratio index (URI) was selected as the indicator to estimate spatial characteristic of land surface temperature. The paper quantitatively analyzed the spatial characteristic of LST by calculating URI of Beijing area, each zone between ring road and each profile buffer. The results show that difference of LST is significant in Bejing. LST of urban area (including East district, West district, Chongwen district and Xuanwu district) is higher than other regions. UHI show multi-center distribution pattern. Among all administrative. districts, the URI of Shunyi district and its mean LST is the highest, and the value is 0.6210, the mean LST is 38.08degC. The URI of urban area is 0.6118, its mean LST is 37.18degC. The mean LST is 36.97degC in the fifth ring road zone, the mean LST is 35.18degC beyond of the fifth ring road zone. Among all zones between ring roads, the highest URI is in the zone between the fifth ring road and the fourth ring road, the value is 0.6327, and the mean LST is 37.48degC. Among eight profile buffers, the URI of east profile and south profile buffer are higher than others, and the URI of west profile and north profile buffer are lower.