When a building blocks the wind blowing across it, part of the wind will escape over the top of the building. Some will pass around the edges of the building while a majority of the wind will get down to the ground. The channeling effect of wind for an escaping path, together with the high wind speeds associated with higher elevations, generates high wind speeds in the region at the base of the building. At the base level of the building, there are three locations of strong pedestrian level winds:
(i) Arcade passages – wind flow is generated by the pressure difference between the front and the back of the building.
(ii) At the front of the building – high wind is produced by standing vortex.
(iii) At the corners of the building – high wind is induced by corner flow.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.