Mobile measurements of microclimatic variables through the central area of Singapore: An analysis from the pedestrian perspective

High-density cities, such as Singapore, are currently facing the urban heat island (UHI) effect, a phenomenon that leads to higher air and surface temperatures within the urban area in comparison to the surroundings and is one of the most critical anthropogenic climate change-related environmental issues for contemporary high-density cities. This study aims to investigate the effect of different urban morphologies such as high-rise and low-rise buildings, green areas, and water bodies on the urban microclimate in Singapore. Mobile measurements taken from a pedestrian perspective were conducted for the first time in the central area of Singapore to explore the severity of the UHI effect through distinctive urban morphologies. The Sky View Factor (SVF) was the metric used to quantify these characteristics. During daytime, the air temperature was higher when SVF increased, except for the water body area. Shading showed to be an important factor to decreasing air temperature in the tropics. Reductions by up to 4.5 degrees C were observed due to the buildings shading during daytime, while the cooling effect of vegetation reduced the air temperature by up to 4 degrees C during the daytime and 1 degrees C at night-time. Thus, this study revealed a strong relationship between the decrease in air temperature and greenery coverage in the city. Therefore, understanding the relationship between urban morphology and microclimate conditions may better drive sustainable urban planning and development in the tropics. Finally, it was demonstrated the importance of using mobile monitoring to retrieve granular data that allows identifying specific environmental issues on a hyperlocal scale, which would not be recognised through other monitoring techniques.