The relationship between height to width ratios and the heat island intensity at 22 : 00 h for Singapore

The statistical relationship between urban canyon height-to-width (H/W) rat ios and nocturnal heat island intensities for public housing estates in Sin gapore has been examined. Although a number of similar studies have been co nducted for temperate cities, this is a first attempt at correlating H/W to heat island intensities for a tropical city. Heat island intensities were examined specifically at 22:00 h because a previous study of Singapore's he at island determined that the heat islands were well developed by that time . A total of 17 Housing Development Board (HDB) estates were studied and at least two vehicle traverses were conducted for each estate on nights with a few days of antecedent dry weather conditions. H/W ratios for each estate were tabulated by proportion of building length. The statistical analysis demonstrates that there is a positive relationship between the heat island intensities and the median H/W, such that Delta Tu-r(max) = 0.952 (median H /W) - 0.021, statistically significant at alpha = 0.05 with a p-value of 0. 001 and a correlation coefficient of 0.53. Copyright (C) 1999 Royal Meteoro logical Society.