Temporal and Spatial Characteristics of Urban Heat Island of an Estuary City, China

Worldwide urbanization has significantly changed the landscape in recent decades, which resulted in an urban heat island (UHI) phenomenon. This study quantitatively analyzed the spatiotemporal changes of the urban heat island (UHI) of Zhangzhou estuary city of China, in the context of urbanisation using Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) thermal images acquired in 2001 and 2006. Satellite thermal infrared images were used to determine land surface temperatures (LST). The results demonstrated UHI was evident and had developed in the 6-study years because of the dramatical urban expansion. LST varied from 20.29 to 32.70 ℃with the urban heat intensity of 8.5 ℃and 9.5 ℃, respectively. The increased UHI areas were consistent with the new urban areas developed. The area of UHI has greatly increased, but the ration of UHI area to urban area seems to decrease. The study also indicted UHIs are radiative, with the highest LST on build-up lands due to high impervious structures, followed by farmland and cooled outwards toward forests and water body. It is hoped that the study will be beneficial to land use and urban planning and its management.