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Urban heat island(UHI) effect is the temperature increase in urban areas compared to that in surrounding rural areas and
is caused by a number of factors, such as land use / land cover (LULC)change, increase fuel consumption and lack of
vegetation in urban core areas. The replacement of natural surface types from soil and vegetation to impervious materials
such as asphalt and concrete structures affects the albedo and runoff characteristics of the urban land surface. The
impervious materials have a lower albedo than soil and vegetation and hold more solar energy, which increase land
surface temperature (LST) during the summer season. UHI effects on the center region of South Korea were analyzed
using remotely sensed data. The objectives of this study are to examine the summer-time thermal environment of the
Cheongju city in Korea, review the satellite assessment of the thermal environment of LULC, and compare thermal
environment in 1991 to 2006. Chang detection of thermal environment is performed to determine whether a significant
change has occurred. The average of LST of study area has increased 2.7°C during 15years because of changed land
cover from paddy field and forest to barren, factory, and concrete. This case study indicates that barren, factory, and
residential apartment over on the Cheongju and Ochang increased in the late 1990s and that vegetation area are changing
predominantly in the direction of decreased forest and paddy fields. Decreasing forest and paddy fields are an important
result, as it suggests that directional changes are occurring on the Cheongju and Ochang that are consistent with
experimental urban warming. The most influential factors for controlling the summer-time thermal environment are the
distribution of surface cover characteristics (e.g. LULC) and urban morphology, such as urban consistence materials,
geometry, development stage, and density.
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