The effect of street canyon geometry on outdoor thermal comfort in Colombo

Abstract

Although life in the equatorial tropics is largely an outdoor phenomenon, modern urban development has by and large failed to facilitate such living in a climatically pleasant manner. The approach then, should be an attempt to make the equatorial urban outdoors thermally comfortable. (Emmanuel, 1993) The primary approach to the research is to quantify and compare the thermal comfort implications of critical canyon geometry in warm humid Colombo. It explores street canyons that are currently existing as well as projected under the Sri Lanka, Urban Development Authority Development (UDA) Plan for 2020. Thus, the task is twofold; to report on the thermal comfort effects of the most widespread urban canyons in the city, and secondly to project the change that will occur with the growth of Colombo's built fabric, therefore canyon geometry. The urban fabric simplified using the Local Climate Zone (LCZ) system and surveyed shows the most predominant street canyons essentially encompass the compact low-rise and mid-rise areas of the city. The research reveals that thermal comfort cannot be achieved within the existing and projected urban canyons, for the peak time of the day.