Contemporary urban environments

• What is urban resurgence?

  After a period of decline people move into an area of the city.

  
  

  e.g The london docklands development corporations made the area desirable for young rich people.
• What is Albedo?


  The reflectivity of a surface.

  light surfaces reflect more than dark surfaces.
• What is microclimate? Small scale variations in temperature, precipitate, humidity, wind speed and evaporation (usually in urban areas)
• What is particulate air pollution?

  A form of air pollution caused by the release of particles and noxious gases into the atmosphere.

  can occur naturally but are largely caused by the combustion of fossil fuels.
• What is photochemical pollution?

  Exhaust fumes become trapped by temperature inversions and in sunlight a low ozone forms.

  A type of air pollution associated with high pressure weather systems, dangerous to health (mainly in cities)
• What is temperature inversion? An atmospheric condition where temperature increases with height, stopping convection and trapping pollution.
• What is an urban heat island?


  The zone around and above an urban area with a higher temperature than rural areas
• What is channelling(urban canons)?


  Wind directed down long straight canyon-like streets where there is less friction
• What is venturi effect? Wind squeezing in a narrow gap resulting in pressure decrease and velocity increases.