Uploaded on 2015-10-29 by Lparis

This is a compulsory exercise. This type of exercises affects significantly your overall grade. We encourage you to dedicate some time to answer them as they will help you gain a deeper understanding of the lectures. WEEK 4 - COMPULSORY EXERCISE: HEAT ISLAND EFFECT As was explained in the lectures of this week, an urban heat island (UHI) is a city or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. 1. Check the temperature differences in US cities In this first part of the exercise we would like you to follow the link to the Climate Central website [http://www.climatecentral.org/news/urban-heat-islands-threaten-us-health-17919] and check the temperature differences that have been recorded in US cities and their surrounding rural areas due to UHI effect. ![enter image description here][1] 2. Which are the main UHI effects that you can identify in your area? 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? A recent study* for the city of Tainan in southern Taiwan gives a UHI averaged through the year for as 3.47 ℃. Another recent study** states gives a UHI for Tainan of approximately 3.9 ℃. *Sun Chen-Yi, Urban Heat Island Study Between Different Size of Towns and Cities (June 2015), presented at the joint 9th International Conference on Urban Climate and 12th Symposium on the Urban Environment, Toulouse, France. (Table 3) **Tang-Huang Lin, The Impacts of Urban Development on Urban Heat Island and Regional Precipitation from Ground-Based and Satellite Observations, presented at the TaiCCAT International Conference in Taoyuan, Sept. 24, 2015; (Slide 31). 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. ![enter image description here][2] A street in the city of Tainan, southern Taiwan. Photo taken by author, Oct. 13, 2015 {Rural picture unavailable} Explanation: The high amount of impervious surface within the city collects heat from the sun. Although a few street trees are present, the dominance of the heat-absorptive surfaces increases the UHI relative to a vegetative area, having a low (compacted hiking paths), or no, amount of impervious surface. Also, if you look at the city scene, note all the scooters on the right side that park in the pedestrian area. Oftentimes people park their scooters in the pedestrian zone, and walkers must actually go into the street to continue. This also contributes toxic fumes in the pedestrian zone; walkers, including the very young and the elderly, breathe these fumes in. This domination of pedestrian areas by scooters is ubiquitous in Taiwan, and especially in the south. Walking is very unpleasant here, and motorists dominate the cityscape. The concept of pedestrian zone appears to be an unknown concept here, and urban planners, whose only specialty is processing paperwork, are poorly trained in urban design. 3. Which are the measures you would propose? 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 livable environment to the citizens? ▪ Install rooftop gardens ▪Reduce impervious surfaces and implement stormwater runoff LIDs (Low Impact Development) along with other green techniques for a more efficient and cost-effective approach. ▪ With the abundant sunshine here and the ocean surrounding the entire island, incorporate solar technology and other alternative energy technologies. ▪ Reduce dependence on scooters, which greatly contribute to the street-level ozone problem and its associated health risks (childhood asthma and other respiratory illnesses), including very common accidents caused by wild scooter drivers. Even though scooters require less parking space than 4-wheeled vehicles, scooter drivers are allowed to drive and park these on sidewalks, which comes at the expense of a pedestrian orientation. ▪ Implement a light rail system to reduce usage of cars and scooters. ▪ Reduce the “mean streets” which likely lower bicycle usage and create an anti-friendly pedestrian environment. This is especially bad for the elderly. ▪ Prohibit vehicles on selected streets, and turn these into linear green systems for pedestrians only. ▪ Some shops, and it appears especially clothing stores, blast their air conditioners at high speed yet leave the ingress/egress to the shop wide open for the cold air to simply blow out. Typical dimensions for small shops for this ingress/egress are about 3 meters x 3.6 meters (10 feet x 12 feet). This is insane. City regulations should prohibit such practices to reduce frivolous energy demand. ▪ Require retractable (to respond to typhoon winds) window awnings to reduce solar heat. ▪ Use vegetation on exterior walls 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. I was unable to find information on UHI policies for this city. The local government claims to have a low-carbon policy and ordinance (“Low-Carbon City Self-Government Ordinance”), with projects (http://tainan.carbon.net.tw/LowCarbon_Tainan_English/About.aspx). The city also states several environmental efforts, but provides no actual data, information, or substantive statements. The “efforts” are only stated as: Flagship Initiative 3: Ensuring Three Types of Sustainability: Environmental Sustainability, Sustainable Development, and Financial Sustainability Flagship Initiative 4: Realizing Tainan’s Four Goals of Becoming a Cultural Capital, Low Carbon City, New Tech Town, and Tourist Paradise Source: http://www.tainan.gov.tw/tainanE/page.asp?nsub=A1A200 What these really mean, I cannot say. Not being a native Chinese reader, I am possibly unable to access such information. [1]: https://edxuploads.s3.amazonaws.com/144610506584838.jpg [2]: https://edxuploads.s3.amazonaws.com/14461051884068949.jpg