Detecting changing trajectory of urban heat island using Gaussian model in Beijing, China

Changing trajectory of urban heat island (UHI) in Beijing from 2004 to 2008 was determined by Gaussian model using daily MODIS/LST data for exploring the general variation of UHI location and distribution characteristics. The results showed that the daytime UHI centroid annually moved along southwest-northeast direction during the period and seasonally varied with a northeast-southwest direction in a large range, while the nighttime UHI in April-June and October-December had a southward trend and that in other months moved along east-west direction near the city core. The spatial characteristics of the summer daytime UHI was primarily correlated with NDVI, while that of the nighttime UHI was mainly related to NIR/SW albedo in 2004-2005, but to NDVI after 2006. Finally, a considerable expanse of UHI was observed in the day of 2007, and a contrast seasonal change of UHI magnitude, extent and volume happened between the day and night.