Uploaded on 2016-05-02 by PeterNormanSmith

Surprised to see Portland OR on the top-10 list as I don't think of it as baking in hot sun. Perhaps this is due to a dense urban form with few shade trees. **2. Effects in my area** UHI are present across the Greater Toronto Area, as shown in the map image. I’ve highlighted Georgetown – where I live – with a black arrow. There is a noticeable difference in UHI intensity between the area at the arrow, with well-established shade trees (21-26C) and both the main commercial strip (to the East) and the areas that were under construction in 2004 (> 28.4C) to the South-East, where there were fewer shade trees. ![Heat Island Effects in the GTA 2004][1] Also of interest, is that the Toronto central business district (indicated by the red arrow) which has many 40+ storey buildings has a lower UHI effect than the adjacent low-rise areas. There is also a lake-effect reduction in UHI extending a few kilometres inland. Map is from: http://www.urbanheatislands.com/toronto **3. Propose UHI relieving measures for GTA** Planting of deciduous trees in streets. These will provide shade in the hot summers but allow solar radiation to reach the surface in the cold (-5 to -22C) winters and in spring to warm the ground. **4 Is UHI effect concerning policy making in GTA?** Yes, the civic entity, City of Toronto, has enacted bylaws to force the use of green roofs on larger buildings and has an urban forestry team dedicated to maintaining urban shade trees. A UHI summit was held in Toronto in 2010 to explore mitigation efforts. http://www.cleanairpartnership.org/urban_heat_island However, outside the formal City of Toronto (termed locally “The 905” after the telephone area code – the City of Toronto’s being 416) there has been less attention to UHI issues. [1]: https://edxuploads.s3.amazonaws.com/1462202394937527.jpg