Uploaded on 2016-03-31 by miquelguerra

Several Studies have been carried out in Dublin with the purpose of establishing the intensity of the Urban Heat Island present in the city. A study carried out by Paul J. Alexander and Gerald Mills and published in 2014 called ' Local Climate Classification and Dublin's Urban Heat Island' ([http://www.mdpi.com/2073-4433/5/4/755][1]) concluded that "under ideal synoptic conditions (...), a maximum nocturnal air temperature difference of more than 4ºC was detected between urban and non urban Local Climate Zones beyond the urban fringe". Dublin city sprawls over a large area. Single family residential dwellings are the most common residential typology and building heights are generally low, resulting in a very horizontal city. ![Grand Canal Dock, Dublin][2] In this image, the street canyon configuration can be seen with tall, fully glazed buildings at either side of the road. Radiation is captured and remains in the street canyon due to the multiple reflections. This entrapped solar radiation and the inert long-wave radiation lead to higher surface temperatures of the buildings, thus increasing the temperature of the street. Additionally, the presence of high velocity winds in the area combined with the torturous geometry of the buildings would contribute to build up of heat in certain areas of the urban environment. One can also imagine the high density of traffic during rush hours and the emissions from this type of buildings to keep a desired internal temperature for its occupants. These 2 factors, in conjunction with the absolute lack of vegetation, would also contribute negatively to the Urban Heat Island effect. ![Canal in Kilcock, Co. Kildare][3] In this other image, the street canyon configuration disappears. This is a wider street that incorporates vegetation, running water, a pedestrian route, a vehicular way and 2 storey buildings all in one section. The vegetation and the running water absorb radiation and contribute to the regulation of temperatures in the area. The radiation remaining in the street is practically nonexistent and only the Surface Urban Heat Island would be an element of study here. The buildings on the right hand side of the image are traditional 2 floor constructions built with thick rubble stone walls with a lime mortar finish and timber floor and roof construction. All of them count on traditional heating systems in the shape of open fires, thus reducing undesired emissions. Finally, traffic volumes are really low in the area, which contribute to a low emission and healthier environment. **3. Which are the measures you would propose?** Fully glazed buildings are appearing indiscriminately throughout Dublin. In general, these buildings require an additional load of energy to keep their internal temperature to a desired standard both in winter and summer. For this reason, I would put in place regulations to limit the amount of energy required for a building to function, depending on its use, to a more sustainable figure. A recent study carried out in UCD (University College Dublin) shows that affluent areas of Dublin city have more trees and green spaces than the rest ([http://www.ucd.ie/newsandopinion/news/2016/feb/29/affluentareasofdublincityhavemoretreesandgreenspaces/][4]). I would propose a clear urban strategy to gradually increase the surface of green spaces in the areas that currently are more deprived of them, so living in a healthy environment wouldn't depend on your wallet. **4. Is UHI effect concerning policy making in your area?** Although due to the climate in Ireland, the urban heat island effect isn't as worrying as it would be in other European capitals, there are 2 main measures that planning authorities are implementing that will, directly or indirectly, have a positive impact on the UHI effect: 1) New commercial and residential buildings in Dun Laoghaire, Dublin, must adopt low energy standards ([http://www.irishtimes.com/news/environment/new-buildings-in-dun-laoghaire-must-adopt-low-energy-standards-1.2103215][5]) This measure will result in less energy consumption and therefore less damaging emissions from the buildings. 2) Green roofs in Dun Laoghaire, Dublin, will be mandatory on new apartment, commercial, leisure and educational buildings ([http://www.independent.ie/irish-news/news/green-roofs-to-take-root-on-capitals-skyline-34116888.html][6]). This measure will reduce the 'albedo effect' by diminishing the amount of heat reflected from the roofs back to the atmosphere and will also provide a better thermal performance to the building. [1]: http://www.mdpi.com/2073-4433/5/4/755 [2]: https://edxuploads.s3.amazonaws.com/14594561939325653.jpg [3]: https://edxuploads.s3.amazonaws.com/14594565106409929.jpg [4]: http://www.ucd.ie/newsandopinion/news/2016/feb/29/affluentareasofdublincityhavemoretreesandgreenspaces/ [5]: http://www.irishtimes.com/news/environment/new-buildings-in-dun-laoghaire-must-adopt-low-energy-standards-1.2103215 [6]: http://www.independent.ie/irish-news/news/green-roofs-to-take-root-on-capitals-skyline-34116888.html