Investigating the effect of urban configurations on the variation of air temperature

Abstract

High temperatures in urban areas affect the health and wellbeing of urban dwellers. Malacca City has undergone a tremendous growth during the last decades, particularly after its designation as a UNESCO World Heritage Site in 2008. As a result of urban development, two dominant urban configurations were formed in Malacca: the heritage site and contemporary urban areas. This study examines the effects of aspect ratio (H/W) on air temperature in two urban configurations in Malacca. The three-dimensional microclimatic modelling system ENVI-met (version 3.1) was used to simulate the summer time air temperature variation in the typical urban setting of a heritage site and contemporary urban area. Aspect ratio was found to have a considerable influence on the air temperature distribution in both areas. The daytime air temperatures decreased with increasing aspect ratio. The simulation results showed that during the daytime, the heritage site (aspect ratio of 2.6) was warmer than the contemporary urban area (average value of H/W = 1.6), and that cooling occurred more quickly in the latter. The results of this study provide useful information for planning, building and modifying urban structures.