This study assesses and analyzes the urban geometry of central business districts: Makati and Ortigas, which affect night-time urban heat island. This involves grouping urban canyons into four (4) transect zones (N-S, E-W, NE-SW, or NW-SE) and measuring variables such as aspect ratio (H/W) and percentage of open space on each transect zones. The paper discusses why a particular area experiences higher night-time surface temperature than others.
Specifically, the study will determine the average aspect ratio (H/W) and percentage of open space of each urban canyon. These variables will be subjected to regression analysis to understand the interplay of variables on street patterns in relation to prevailing wind direction. Urban design strategies will also be identified based on the results of the variables to reduce heat accumulation.
It is discernible that the urban geometry of the Makati CBD area is more complicated than that of Ortigas and there are quite a number of continuous open spaces in Ortigas as compared to Makati. These open spaces are being used as parking areas and a limited number of parks. For that reason, ventilation in Ortigas can easily reach the ground level. Also, the street orientation in Makati is generally perpendicular to the prevailing wind, compared to the streets in Ortigas. This means that urban canyons in Ortigas are generally more ventilated which may have resulted to the lesser surface temperature at night.