Fieldwork Urban Heat Islands

        For this Fieldwork the following Research Question was elaborated:

         To what extent does “Parque da Luz” influences the heat islands within São Paulo’s CBD?

This question focus on the solution for urban heat island, we have to answer if “Parque da Luz” is helping or not to diminish UHI in São Paulo’s CBD.

Because of that my hypothesis is:

        Further the place is from “Parque da Luz” warmer it is, therefore the park helps on diminishing UHI in São Paulo’s CBD.

This answer will be proven right or wrong in the Conclusion but my point in this hypothesis is that the park does help the CBD urban heat island problem because it seemed that further the place is from the park, warmer it becomes.

Methodology

We read about UHI, after it we organized our plans and divided ourselves in 3 groups to collect datas from the three different places, which are: “Parque da Luz”, “Estação da Luz” and “Estação Júlio Prestes” (these places can be located on the map 1 and photos can be seen in the Attachements).

With this map, we can understand the distances between the Fieldwork Places:

- “Parque da Luz” to “Estação da Luz” is 193,39 meters.

- “Parque da Luz” to “Estação Júlio Prestes” is 772,93 meters.

- “Estação da Luz” to “Estação Júlio Prestes” is 602,82 meters.

Map 1 - The three places studied:

Source: Google Earth                                         Author: Teresa P. Nogueira

A list was made of the chosen items to be analyzed and measured every 15 minutes from 9:45am until 3:45pm (with one hour break for lunch at 12pm) on the work places.

The items measured were (see more details in the Attachements):

• Time
• Temperature from dry bulb
• Temperature from humid bulb
• Temperature of the ground
• Cloud coverage
• Type of clouds
• Wind intensity
• Wind direction
• Atmospheric pressure        
• Car Flux
• Thermal sensation
• Relative Humidity
• Altitude
• Level of construction

        

The colour, texture and materials of the constructions, season of the year are also factors that influence UHI but we did not focus much on that.

The data collected was treated by making tables and by its higher influence and importance.

Presentation and analysis of the Data

To have better results to answer my Research Question and prove that my hypothesis was right or not, I will organize the data collected in graphs and tables on this chapter.

The table below is the average of the most significant measurements collected during the fieldwork. With this table it is possible to observe the differences from the three places studied.

“Estação da Luz” is the hottest place comparing to the other two, and “Parque da Luz” is colder.

Table 1 – the average from different datas on the three places

Source: Fieldwork                                                                                   Author: Teresa P. Nogueira

The graphs 1, 2 and 3 below are used to show the difference from the real temperature to the thermal sensation in each place studied.

It is possible to notice that the thermal sensations in “Estação da Luz” and “Estação Júlio Prestes” are lower than the dry bulb temperature, around 2ºC below.

In “Parque da Luz” the thermal sensation is closer to the dry bulb temperature, because of the trees and shadows.

Graph 1 –

Source: Fieldwork                                      Author: Teresa P. Nogueira

Graph 2 –

 Source: Fieldwork                                      Author: Teresa P. Nogueira

Graph 3 –

Source: Fieldwork                                          Author: Teresa P. Nogueira

The graph number 4 demonstrates the evolution of the dry bulb temperature on the three studied places during the day.

Graph 4 –

Source: Fieldwork                                      Author: Teresa P. Nogueira

Comparing graph number 4 with the graph 5 below, which has the average dry bulb temperatures of the three places, it able us to conclude that “Estação da Luz” is hotter than the other two. The two other places have lower temperatures in the morning, but also rise during the hottest hours of the day, in the afternoon. However, between 1:30pm and 2:45pm, the temperatures are a few degrees higher than in “Estação da Luz”, but this does not have a great impact because it continues to have the greatest temperature average.

Because of its distance, “Estação Júlio Prestes” should be hotter than “Estação da Luz”, but its average temperature is actually 0,2ºC lower. Which I believe is because in “Estação Júlio Prestes” there is a wind corridor and there are a few vegetation in front of it, contrasting with “Estação da Luz”, where there is only concrete.

It was stated an edification level in the three places; “Estação da Luz” has an average of 13,3m, “Estação Júlio Prestes” has a 23m average and “Parque da Luz” is only 9,4m. The edification level intensifies the temperature because of the concrete, as it was said in the introduction. So again, “Estação Júlio Prestes” should be the hottest one.

Graph 5 –

Source: Fieldwork                                      Author: Teresa P. Nogueira

Conclusion

        Through the processes of analysis of the data collected I can say that my hypothesis, “Further the place is from “Parque da Luz” warmer it is, therefore the park helps on diminishing urban heat island in São Paulo’s CBD” was partially right.

The temperature on the two stations are higher than on the park; but the odd thing is that “Estação Júlio Prestes” should have its temperature average higher than the other because it has a lot of the factors that intensifies the temperature, it is farther away from the park, its level of edification is higher, but “Estação da Luz” continues to have the higher temperature average.

I believe that without the park, the temperature on these places would be much higher than it is today. That is why the park helps, but not much, on diminishing urban heat island in São Paulo, because its area is not enough for the surrounded urban area.

If I could do this fieldwork again, my hypothesis to the Research Question would be: “The park area does not help to diminish urban heat island in the three places studied because the other factors are stronger than the vegetation on the park, therefore the park does not change anything in the temperature of its surroundings.”

        I think that to improve the data collection and the information, we should have more precisely tools to better measurements and results. We could also have more factors analyzed like the colour, materials of the constructions to see if they have a big influence on UHI.

For example for measuring wind intensity we could have equipment, not just a table and our guessing. And also, for a climatology work to be valid the data needs to be collected for at least 30 years.

If we were in more people we would not need to stop the measuring for one-hour lunch and we would be able to measure the data from other places as well, to have more examples of distances and temperatures.

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