Uploaded on 2017-01-13 by Hannah Bessett

1. Where would you measure the maximum UHI intensity? If I were going to measure the maximum UHI intensity, I would go to both the busiest part of my city and the most rural, then compare the two readings. I live closer to the rural region of my hometown, but it is not particularly well developed to begin with and so I could not decide where the heat effect would be most intense. However, if I am a little more flexible about where my city ends and the neighboring one begins, I would actually use the downtown Denver as my city center, specifically near the Wells Fargo Center, where the traffic (both human and automobile) is at what I perceive as its peak. As for my rural location, I would take readings from the area just outside of the grounds of Denver International Airport. It is extremely underdeveloped land, with miles of grassy prairie without many businesses or homes. 2. When (at what time of the day) is the UHI intensity at its maximum? The temperatures would ideally be collected during the middle of the night, as they would not be thrown off by factors such as shading from the sun. It would ensure that the difference in heat (if any exists) between two places would be brought about by the urban environment only, such as from cars and electrical units. However, due to the fact that I am completing this task on my own, it is impossible to get completely accurate readings while actually being on site. I cannot be in two places simultaneously, but time of night must be a fixed point to be accurate. To try and solve this issue, I instead opted to use an online search to gather the temperature readings. While it may not be as precise as taking the readings in the field, it ensures that the data was controlled for time of night as a variable. 3. How should you set-up your sensor? As stated in the video, I would try and have the sensor held at average human height, which is around a meter and a half to two meters. I am a little more than a meter and a half tall, and so were I gathering data from my phone on site then I would try and hold it at eye level in order to get a good reading. In a way, though, it is good that I am not using data collected on my own device, because it would be extremely difficult to control for the height at which I held my phone from one place to the next without having some kind of stand where I could lock it in place. Also important to note would be to let the sensor on the phone adjust to the actual outside temperature, as opposed to that in my pocket or car. MEASUREMENT DATA FORM Location 1. Name of city Denver 2. Country United States of America 3. GPS coordinates or street name/number of city location (A) and reference location (B) 3.1 Location A: 1515 Arapahoe Street #400 3.2 Location B: 8500 Peña Boulevard 4. Describe immediate surroundings (within 200 m of site) in terms of building type/morphology and vegetation (e.g. type of land cover, building heights, street width, type and amount of greenspace/trees and their height) 4.1 Location A : because I am using the internet to gather my readings, I will speak to this location using only my personal knowledge of the area as well as the street view accessible via Google Maps. It is not wholly accurate for the location in real time. The area is almost entirely paved with a wide street and walkway, though there is a very small field of grass that is nearby the building that seems to be made to try and make the space more attractive to people. A few shrubs can be found in specially constructed gardens, and there are some small trees that were planted both in front of the address and down the opposing street, though there are not very many of them. A parking garage is directly across the road and there are a large number of cars going by despite the later hour, going in both directions. 4.2 Location B : again, I am using the internet to gather my readings, and so my description comes only from my personal knowledge of the area as well as the street view accessible via Google Maps. It is not wholly accurate for the location in real time. In contrast to my central location, this address does not have a great deal of pavement (though there is certainly a large amount farther out, where the air strips are), nor are there many buildings in the surrounding area save for the airport itself and the intermittent control towers. Although the airport itself is obviously very busy and there are many vehicles (both terrestrial and airborne) moving to and fro, there are not many connecting roads open to the public. Father out, there is mostly open prairie land with tall, though dry grass, with minimal trees and activity at night, and only manmade structures for shade. Sensor 5. What sensor did you use? I am not really sure what type of sensor is being used to gather the temperature. As mentioned a few times above, I am using the internet in order to gather the data necessary for this task rather than doing so in real time. All I can gather from looking it up is that the data that comes up when you search a location and its temperature is what is being gathered by other people using their Android phones in the area, somewhat similar to how Google utilizes the travel data to give a rough estimate of how long it will take for someone to get from point A to point B. This is not a known fact, and instead an educated guess after gathering the data from Google as it sits. Otherwise, I would be using the built-in thermometer on my phone, as I can't use an external one. 6. What is the accuracy of the sensor? if available) Because I am not entirely certain of the type of sensor that is being used, I am similarly uncertain of the accuracy of it. If it is a cell phone thermometer, as theorized in the above question, then its accuracy is dependent on how the person is using it. As mentioned in question three of this exercise (not the form), having the phone in one's pocket would throw off the readings, as the person's body temperature would throw it off. Similarly, if it is in someone's pocket, it is too low for the proper reading, which would ideally be taken around a meter and a half. Plus, given the differing heights of people, the sensor would not be held at a constant height, which would make it so the proper controlled variables were not, in actuality, controlled. Lastly, cell phones produce their own heat under heavy use, further complicating results. Measurements 7. Time of measurements? (dd/mm/yyyy and 00:00 PM/AM) 7.1. Season : winter 7.2. Date : 1/11/17 7.3. Time*: A: 8:00PM B: 8:00PM 8. Set-up of sensor (e.g. height above surface, distances from buildings etc.) Once again, I am not entirely certain of what device Google utilizes to gather their temperature data. My theory so far has been that it is the result of information gathered by phones in peoples' pockets at that point and time, in which case it is impossible to tell exactly what all these variables are. This is not the only but by far the most glaring flaw with using data obtained from a third party, but I am currently unable to travel and gather these pieces of information personally. I would assume that these sensors are being held approximately a meter from the ground if not a little lower, merely because people often use them at waist or chest height. They are also likely to be close to the buildings, as walkways and the like extend only so much from these structures. They may also, unfortunately, be in peoples' pockets. 9. Duration of measurements? (one measurement or an average value of measurements taken during a certain period, e.g. 10 minutes) The measurement obtained here was a single one, once more rendering it an inaccurate piece of data. However, if the data is truly being collected by peoples' phones, it seems likely that the measurement is a running average of what is being collected in real time. This type of accuracy may even be enough to quell the negative effect of the other irregularities, and it is worth pointing out that crowd sourcing is becoming a more and more influential means of gathering data, particularly for architects. It appears that the information changes with the hour, as when I began filling out this form it was around seven rather than eight, and although the reading was not different, it changed when I checked it later to gather more information. The sun had already gone down around six, and so the temperature had had plenty of time to drop and then stabilize. 10. Weather during measurements 8.1 Wind speed : 8 mph, 12 mph 8.2 Amount of clouds: partly cloudy, mostly cloudy 4. How big is the temperature difference between where you measured the maximum urban temperature (location A) and the reference location (location B)? 31 degrees F - 26 degrees F = 5 5. Can you explain the difference? a. What influence does the weather have on the UHI magnitude? (e.g. season, the wind, clouds etc.) Because it is winter, I expected the UHI to be lower than it might be during the summer, and knowing what I know about Denver I can assume that this would be an accurate guess. It was listed as number three on the website referred to us in one of the earlier videos, with temperatures in urban settlements sometimes twenty-three degrees higher than those collected in rural areas. It is also important to note that the weather was different in these two areas, as the wind in the under developed territory was nearly twice the speed of the wind in the urban center. This pushed the temperature further down, and therefore led to a more intense result than it would have been were the wind speeds equal in both places. It was also cloudier and threatening to rain near the airport, once again pushing the temperature down via natural means. b. What influence do the immediate surroundings of the places where the measurements were taken have? The city center is a location surrounded by architecture, which, as we have been taught, are inefficient at releasing their heat even after the sun has gone down. Similarly, it is right next to a street that is busy at almost all times, and the heat energy generated by the cars is not given the chance to dissipate. Lastly, because it is winter, most of the buildings have the heat running during the day, and because the heating technology is usually better in the city, their effect remains even after the device has been switched off. Near the airport, although there are a large number of vehicles, the main building's roof is white and reflects most of the heat from the sun during the day. It also is in the middle of a large prairie, and so it is easier for the wind to break up concentrations of thermal energy. 6. Can you elaborate on a number of interventions against the UHI in your city, which are carried out by different actors? (e.g. government, city council, private initiative etc.). In case you cannot find interventions to prevent UHI in your city, can you think of possible interventions? Yes. As briefly mentioned in the description of the location, the city center is decorated with a variety of trees and plants. They are not, however, particularly tall, and it is generally preferred of trees in urban settings to be tall in order to provide shade and thermal comfort for the citizens using the walkway. Although not in this particular area (or season), there are buildings that have sprinklers on the roofs and patios that go off intermittently throughout the day during the summer. These, unfortunately, seem to be the only features implemented. It appears as if some of the buildings were constructed using large amounts of windows, which makes it difficult to try and repaint them with lighter colors and prone to absorbing more heat than necessary in the summer months. The building materials are concrete, glass, and steel, all of which have a high rate of heat absorption.