Study on the appropriate selection of urban heat island measure technologies to urban block properties

Toward the appropriate selection of urban heat island measures technology in the street canyon, the introduction effects of the technologies in the typical street canyon are analysed by the model calculation. It is appropriate to use street trees for the improvement of the thermal environment on the sidewalk and high reflectance paint or water-retentive pavement for the reduction of surface temperature on the roadway. Reduction of solar radiation gain to the sidewalk pavement surface is dependent on the location and area of the shadows by street tree. Shadows by street tree are likely to occur on the northern sidewalk of the east-west road than the eastern (or western) sidewalk of the north-south road. While the shadow by the street tree is occurred on the sidewalk, the area of the shadow is proportional to the square of the width of tree crown (the radius) and inversely proportional to the distance of each tree. It is necessary to be considered a priority according to the road orientation and time zone primarily used by pedestrian.