Manipulation of urban geometry to achieve effective wind flow for pedestrian thermal comfort: with special reference to urban development in Colombo 4, Sri Lanka

Abstract

The urban geometries create a physical character or structure at the street with relating to neighboring local climate. The urban geometry of a specific urban area has the potential to enhance or diminish the pedestrian thermal comfort by manipulating the urban climate and manipulates the behavior of wind by controlling the velocity and wind flow patterns. In such a context the design strategies of urban geometries must be implemented with in depth understanding and considering the pedestrians‘ comfort. The research focus on how the existing urban geometries of selected site impact on wind flow which in reverse impact on pedestrian comfort and the impact of wind flow when these LCZ2 areas convert into LCZ1 areas. Height increase of the buildings and the density would not be an issue if the urban geometry is planned to avoid disturbance to natural wind flow and to maximize wind effects through urban canyons by manipulating H/W ratios. The research findings proved the buildings with high podiums does not help to increase pedestrian comfort in Sri Lankan climatic conditions; since the wind flow in this context is not very strong. The placement of open areas is critical as those could either increase or decrease the pedestrian thermal comfort. Hence, urban planning strategies should be 'site specific‘.