Analysis of the Effect of Urban Geometric Form Factors on Heat Islands in Guangzhou

Abstract

The geometric form factors of urban space include height width ratio (H/W), sky view factor (SVF) and street direction, which directly affect the incidence of solar radiation, and then affect the temperature change of the block. In this study, the representative hot island and cold island streets in Guangzhou are selected as the research objects. According to the intensity and range distribution map of Guangzhou heat island in summer of 2014-2017 issued by Guangzhou Meteorological Bureau, the intersection area with high intensity of 4-year continuous heat island is found out by two-dimensional image superposition. In the region, the typical measurement points and comparison points are selected in groups, the temperature of each measurement point is monitored, and the urban geometry data is collected for comparative analysis. The results show that under the condition of the same underlying surface factor and no significant difference in artificial heat factor, the urban geometry can alleviate the heat island effect, and the measuring points with smaller sky view factor and larger height width ratio (H/W) have lower temperature, and the temperature of each measuring point has higher correlation with the size of SVF. In addition, the direction defined by the long axis of the valley will also affect the solar radiation equivalent of the street pavement, and the reclamation open land is also easy to become a heat island area.