Historical analysis of long-term climatic data to study urban heat islands in Singapore

Abstract

Urban Heat Island is a phenomenon where the temperatures in the urban space are higher than those of the suburban rural areas. The purpose of this study is to examine regional climate change and identify the urban effects on climates of various regions in Singapore. Dry-bulb temperature and relative humidity records of four meteorological stations are analyzed to study regional climate change. Statistically significant upward trends are found in the mean, maximum and minimum temperatures of one station (Changi), whose predominant land use for the past two decades (1982-2001) has been the Port and Airport. Correlation is found between the mean temperatures and the air traffic volume at Changi Airport. A significant upward trend in minimum temperatures is detected at another station (Sembawang) during the period 1991-2001, a period when Sembawang underwent development to become a new town with large numbers of high-rise housing. The other two stations (Seletar and Tengah) show no significant warming or cooling trend. A comparison of Changi and Tengah in terms of temperatures and physical development reveals a significant urban heat island that is becoming increasingly effective in Changi. The mean, maximum and minimum temperature differences between Changi (urban) and Tengah (rural) are found to be highly correlated to the air traffic volume at the airport- an indication that heavy anthropogenic activities at the Changi airport is likely to be the major cause of the historical increases in mean, maximum and minimum temperatures at Changi.