Theory

• Buildings artificially increase the friction on urban winds and reduce wind speed. There are three main effects of wind in urban areas:

  • when urban heat island is at its greatest at night, convectional processes can draw in strong localised winds from cooler surrounding areas
  • clustered of high-rise buildings increases channelling. The venturi effect intensifies the wind speed through small openings
  • vortexes can form from the descending flow, which can sweep around windward corners