Uploaded on 2015-10-20 by jhthurm

I live in a very green part of the city, located right along a cold Mountain river, and in an urban area that’s anyway very green with plenty of water. Hence I do not really remember noting massive differences, apart from the fact that higher situated neighbourhoods in summer are often warmer than the ones at the lake or the rivers, probably as they receive less cooling from the water. 2. Now that you saw the significant effect of UHI in the US cities, can you provide data and information for your own place of residence? No, I did not find any UHI data unfortunately (maybe because the issue is not that pronounced in Geneva). In addition to that, we want you to provide two images; the first one of a city and the second one of its surrounding rural area (preferably one of those areas is your place of residence). Compare the two images in terms of reasons that contribute to the UHI effect of the city. Central Geneva with the Lake: This central area of the city is very dense, though still has the lake, and green lake front. Building height is about 6-8 levels, and streets are quite narrow, so you do notice relatively cool street canyons in summer. Because of the lake, temperatures in summer a relatively cooler than in areas away from the lake. While you might not notice strong canopy heat island issues because of the natural properties, there’s probably a noticeable surface effect due to the high density of buildings, streets, and other artificial surfaces. Note though that buildings and roofs show very light colours (mostly white or beige buildings with red roofs), which might mitigate the later effect to some extent. There is hardly or any polluting industry in the central areas of the city, though traffic can be quite congested due to strongly reduced street capacity (in the core areas, boulevards have been equipped with bus and tram lanes, while space for cars has been cut back). In addition to that, parking spaces are very scarce in the center. Hence overall there are not many cars coming into the center compared to other cities, and public transport ridership is high (bike usage is growing, but still small compared to North-western Europe). https://edxuploads.s3.amazonaws.com/14453179262621146.jpg New residential settlement outside of Geneva: This area of new-build houses of semi-detached houses shows lots of green, with low building and street density. Though there are a few trees, and area also shows plenty of open green areas. This last point might contribute to lightly pronounced canopy heat island effect. Transport almost entirely relies on the car, so we’ll see heat effects being amplified by resulting pollution. https://edxuploads.s3.amazonaws.com/14453179634214536.jpg 3. Which are the measures you would propose? In the central area of town I would try to grow more trees in the streets, and also create more grass and green space on top of the buildings (i.e. rooftop gardens). As I wrote above, the use of bike could be improved, with more bike lanes and covered bike parking areas to be installed. Furthermore, I would introduce an overall speed limit of 30 km/h in the whole city. Regarding the residential area outside of the urban core, I would also try to add more trees, as there are still plenty of open green space (leave some for sports though). Though the car would probably always remain the main mode of transport, I would try to foster bus and bike ridership where feasible. If you could take part in the decision making process of an initiative related to the UHI effect, which are the measures that you would propose in order to reduce it and provide a more liveable environment to the citizens? Three key interventions would be part of my initiative: I would introduce 30 km/h speed limit in the whole city, to reduce pollution from cars (and accidents). At the same time, I would leverage new information systems to control and improve the traffic flow. In the core area I would introduce a congestion charge to limit the amount of cars entering the center (similar to what Stockholm and London have done). The money from this charge would be used to improve the infrastructure for bikes and public transport. I would foster the creation of parks (by destroying low density buildings and moving out some activities), more trees in streets where feasible, and green roofs. The latter initiative would limit the potential for photovoltaic systems in central areas, though I think large retail, logistics, and production buildings outside of town are anyway better suited for that. I would also drive the creation of narrower street canyons by allowing higher building heights. The increased traffic because of the resulting higher office, retail, and housing density would need to be countered with more public transport (which could be operated more efficiently because of that higher density). 4. Is UHI effect concerning policy making in your area? Do you know of policies in your community that are planned to reduce the UHI effect? Provide us with information regarding any visible results. The Canton as well as the City of Geneva have several projects to improve the city climate (not specifically calling out the UHI though) – here a few of them. Urbanature – project to create more green spaces across the city, more evenly distributed (the city already has 20% parks now, and is among the greenest in the world) CEVA – urban rail project to reduce car traffic (especially from living in the French suburbs, which are currently not well integrated into the city’s public transport system). Velib/Velospot – several attempts are currently being made (private and public) to launch an extensive bicycle rental system, similar to how other system already created (Paris, Barcelona, or London for instance).