Principal Investigator : Dr Wong Nyuk Hien
Figure 1: Temperature profile for the whole Singapore island.
Figure 2: Urban Heat Island profile of Singapore
Figure 3: The impact of the neighbourhood park on the ambient temperature of the surrounding HDB blocks of flats
This project, co-funded by Building and Construction Authority (BCA) and NUS, is a multi-agency project involving BCA, Housing and Development Board (HDB), National Parks Board (NParks), Meteorological Services of Singapore (MSS) and National Environmental Agency (NEA). The Centre for Remote Imaging, Sensing and Processing (CRISP), which is a research institute of NUS, is also involved. The main objective is to study the severity and impact of Urban Heat Island (UHI) on the environmental conditions of Singapore and explore measures to minimize its impact.
Based on the satellite imagery analysis as well as the extensive field measurement, the temperature profile of Singapore has been established (Fig. 1). The hot spots of Singapore have also been identified and the results showed that the heat island intensity in Singapore is about 4.5° C (Fig. 2). The lower temperatures were mostly detected in the northern part while higher temperatures were observed in the south, especially in the CBD area. The results of the survey indicated the strong influence of vegetation on the ambient temperature. Analysis of the weather data at 4 weather stations was also carried out and it was found that for Changi, the temperature increase over the last 20 years was about 1° C.
One of the possible measures to mitigate UHI is to reintroduce plants into the built environment in the form of rooftop gardens, balcony gardens, vertical landscaping, as well as neighbourhood parks. Field measurements conducted to explore the thermal protection of rooftop gardens in Singapore showed that the installation of rooftop gardens would significantly provide thermal protection to buildings and improve the surrounding environment. Rooftop gardens can efficiently reduce the surface temperature of roofs. The maximum temperature recorded by having plants around was around 30° C and this can reduce the cooling energy consumption of a building by about 20%. Field measurements carried out in neighbourhood parks showed that not only the parks recorded lower temperatures but also the vicinity of the parks (Fig. 3).
The results of this research will be useful to the long-term planning of Singapore's buildings, which needs to take into account the implications of temperature rises as well as the impact on energy consumption.