The influence of buildings on ground level wind conditions

Abstract

Changes in the morphology of modern cities with the increasing incidence of high rise construction, have signifi­cantly altered the built environment and its microclimate. In fact in many cases the presence of tall buildings has created what may be regarded as inhospitable micro-environments and even at times dangerous ground level wind conditions. As a result an accep­table wind environment in outdoor public areas, has become a major consideration for new building com­plexes, as too remedial steps which may also become necessary in existing problem areas. The aim of this study was to examine those situations which led to severe amplification of ground level wind speeds in a built environment. A case study conducted in Cape Town is used to illustrate how buildings may alter wind conditions and create severe wind problems for pedestrians. Guide­lines and some practical steps are given for controlling the flow of air near the ground to within acceptable levels, in terms of pedestrian comfort and safety, are finally noted.