EFFECTS OF GROUND SURFACE MATERIAL ON OUTDOOR THERMAL COMFORT IN OPEN SPACES: A CASE STUDY ON NUS SPORTS FIELD

Abstract

Urban Heat Island (UHI) is a problem that Singapore is facing as an urban country. This study will conduct a baseline study to investigate UHI in the National University of Singapore Kent Ridge Campus and determine hot spots in the campus. Localized field measurement will then be conducted at an identified hot spot to evaluate the effects of ground surface material on outdoor thermal comfort. The baseline study used ground weather stations to measure air temperature, wind speed and solar radiation. The results identified 3 hot spots in particular with maximum temperature (Tmax) above 31.49°C. Further evaluation led to the sports field being selected for localized measurement as a location with heavy outdoor usage. The localized measurement investigated 3 ground surfaces at the sports field, which were grass at the real turf, artificial turf and painted concrete at the basketball court. The results found that the artificial materials at the artificial turf and basketball count generally registered higher surface and air temperatures than the real turf. Real turf retains the most heat, while artificial turf and basketball court retains about 22% and 30% less than the real turf respectively. Natural materials provide greater thermal comfort than artificial materials. Recommendations were made to increase thermal comfort at the sports field, including shading, cool paint and misting. Limitations of the study include equipment unavailability which affected the ability to collect parallel datasets at the artificial turf and basketball court. Unintentional human interference and safety risks due to human activity were also concerns.