World Cities Summit 2024
Cooling Singapore 2.0: Understanding Urban Heat
Overview
Urban overheating, caused by the urban heat island (UHI) effect, is a problem that requires urgent attention. Inaction could lead to fatal consequences on health and infrastructure, and negatively impact the day-to-day running of cities.
Cooling Singapore 2.0, a multi-institutional project, is developing a Digital Urban Climate Twin (DUCT) for Singapore, which integrates different computational models (e.g., environment, land surface, and traffic) and regional and microscale climate models. The DUCT will enable policymakers to simulate and assess the impact of various heat management strategies.
SMU is collecting data on urban heat at various sites in Singapore to contribute to a comprehensive, systems-level picture of Singapore’s heat issue.
Sites
City Centre
The research team used SMaRTy, a mobile biometeorological cart, to understand the thermal experience of pedestrians as they walk through different urban environments in the City Centre. SMaRTy, Singapore’s first high resolution mobile meteorological setup, is equipped to measure wind speed, wind direction, air temperature, relative humidity, and solar radiation (shortwave and infrared) in six directions. These are essential weather elements that affect a person’s thermal comfort.
L: Using SMaRTy, researchers can assess outdoor thermal comfort of pedestrians
through the measure of Mean Radiant Temperature. R: The visualisation of hot and
cold spots (red and blue) along the route enables researchers to understand how
various shade profiles (e.g., buildings, trees) impact a person’s thermal
experience.
In the City Centre, SMaRTy collected data around the SMU campus and Singapore’s Heritage District. The maps above, which show SMaRTy’s route, represent a pedestrian’s thermal experience as he or she moves through this route. The data shows that shade, be it tree shade or building shade, plays an essential role in keeping people cool in a highly urbanised area.
Bishan-Ang Mo Kio Park
Similarly, the team used SMaRTy when studying Bishan-Ang Mo Kio Park. In addition to utilising this approach, the team also carried out outdoor thermal comfort campaigns at the park.
Thermal comfort is the condition of the mind that expresses satisfaction with the thermal environment.
Assessing outdoor thermal comfort is important to understand the effectiveness of urban design and landscape in providing comfort, which in turn affects public space utility. To understand outdoor thermal comfort in both objective and subjective ways, the team’s campaign comprises data collection from microclimate sensors and surveys with park-goers.
The data from both SMaRTy and the thermal campaigns shows that the coolest places in the park are shaded areas with relatively high density of trees, while the hottest places are non-shaded areas with no trees.
L: The Vaisala, a microclimate sensor, collects air temperature, relative
humidity, wind speed, and globe temperature data at a one-minute sampling rate.
R: SMU students engage park-goers with both paper and digital survey
questionnaires at Bishan-Ang Mo Kio Park.
Impact
The team’s data is used to validate models – such as those generated by 3D microclimate modelling software ENVI-met – for the DUCT. Model validation is essential to developing reliable simulations in an urban context.
More broadly, by integrating diverse data via the DUCT, Cooling Singapore 2.0 will encourage a holistic, multi-faceted approach to tackling the UHI effect in Singapore. The DUCT will also be used to evaluate accurate scenarios for future climate analysis.
Lead Researcher:
Winston Chow
Professor of Urban Climate, SMU College of Integrative Studies;
Pillar Lead (Urban Infrastructure), SMU Urban Institute;
Lee Kong Chian Fellow
Funding organisation: National Research Foundation