Urban Heat Island (UHI) becomes a big concern, especially in a subtropical region. UHI not only changes the environment but also affect human life. More energy consumption, high disease transmission rate, and poor air quality are the possible consequences of heat island. In this study, four approaches were employed to 1) investigate the existence of heat island effect, 2) explore a linkage between atmospheric and surface heat island studies and 3) examine the impact on heat budget due to a land cover change.;The four adopted approaches were mobile transverse measurements, a remote sensing technique, fixed station method and a 1-dimensional heat budget measurement. First, a series of 20 mobile transverse measurements were conducted in 2003 -- 2005. Two vehicles with temperature sensors installed were employed to be driven mainly in urban areas in order to quantify heat island intensity. Second, four satellite images were captured in a night of winter, a day of winter, a night of summer and a day of summer in year 2007 and 2008. A ground mobile in-situ temperature measurement team was simultaneously conducted when the satellite passed over Hong Kong in order to explore the temperature correlation between atmospheric and surface heat island intensities. Third, a long-term UHI intensity between two fixed stations was analyzed for 19 years (1989 -- 2007). The characteristic of UHI in a subtropical city was generalized based on the data from two typical meteorological stations. Fourth, a 1-year intensive heat budget measurement was conducted at Ta Kwu Ling in 2007/2008. A comparison of heat flux of net radiation, soil heat, sensible heat and latent heat was made over grass and concrete surfaces.;Overall, the findings of this study were able to examine the characteristic of heat island intensity in Hong Kong and justify the impact of a land surface change on heat budget, albedo and emissivity.
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