Street Geometry Factors Influence Urban Microclimate in Tropical Coastal Cities: A Review

Urban climatologists have moved smoothly towards urban geometry meso-scales as obstruction between buildings, streets, and urban environment. Urban climatologists and designers have expressed that urban geometry parameters affect urban microclimate conditions. Improper functioning of the geometry factors, particularly air temperature and wind speed, can increase the harshness of climate change and Urban Heat Island (UHI) defects, which are more critical in coastal cities of tropical regions. In this regard, the current study aimed to identify the impact of each street geometry factor on urban microclimate through a critical literature review. The research determined a total of twenty seven (27) factors within three clusters; 1) geometry factors, 2) meteorological factors, and 3) streetscape factors. The content analysis calculated the Depth of Citation (DoC) which refers to the cumulative importance level of each factor. The content analysis resulted air temperature (Ta) (DoC = 18 out of 28) is the most important street geometry factor that should be extensively considered in urban microclimate studies in coastal cities. In contrast, the factors (such as air pollution and traffic load) have received a minimum Doc (1 out of 28). The research has also analyzed the importance level of clusters through an expert input study using Grounded Group Decision Making (GGDM) method. The results show that meteorological cluster (92 %), streetscape cluster (86 %), and geometry cluster (85 %) have to be respectively implemented in urban microclimate studies in coastal cities. The research states there are new approaches have not yet been touched by urban climatologist affecting urban microclimate; included; surface materials, sea-borne dust and sand, user’s satisfaction, user’s thermal adaptive behavior. These approaches can potentially exacerbate UHI effects in coastal cities, which need further research.