Edgewood College Campus Heat Island Effect:
Comparing Average Temperatures of Rain Garden and Parking Lot
Authors
Lindsay Haines
Kristina Markgraf
Introduction
Methods
Results
Implications
Conclusion
Introduction
- A heat island effect develops when roads, buildings, and sidewalks
replace natural vegetation.
- Heat is stored in concrete, asphalt, buildings and other structures, and
temperatures increase because throughout the night these manmade structures
give off heat that has been stored during the day.
- A heat island effect is a concern because, especially during the
summertime, surrounding communities can be affected. The greater the heat
island effect, the more air conditioning is needed, thus more air pollution,
including emission of greenhouse gases. Also, high temperatures could
lead to more heat-induced illnesses, and possibly a higher mortality rate
(“Heat Island Effect,” 2009).
- After researching heat island effects in rural and urban areas, we
decided to see if Edgewood Campus had its own heat island effect.
Methods
- First, we gathered and organized temperature data (from years
2003-2008), representing night and day temperatures from the months of
August and February, from both the Edgewood College Campus parking lot and
rain garden thermometers/stations (HOBO® and Onset Computer Corporation).
- The average temperatures were calculated for each year from winter and
summer, and night and day.
- The standard error of the mean (estimator of error bar) was also
calculated along side with average temperatures for each year’s day and
night averages.
- After making bar graphs, we made conclusions about the existence of a
heat island on campus.
| |
 |
 |
|
| Parking Lot |
Rain Garden |
| Heat Stations |
Results
Figure 1. Average temperature (°C) difference between
Parking Lot (PL) and Rain Garden (RG) from years ‘03-‘08 in both February and
August. The error bar (vertical lines on colored bars) indicates the range
of the standard error of the mean.
- According to the results shown in Figure 1, if the difference in
temperature is above zero, the parking lot is warmer, and if the difference
is below zero the rain garden is warmer.
- The average daytime temperature difference in February showed that the
parking lot was warmer. The August average daytime temperature
difference showed an even greater difference between the rain garden and
parking lot than in February.
- The February and August average nighttime temperature differences were
close showing that the rain garden is warmer.
- There is some overlap within the standard of the mean, which means they
are not statistically different; however, since the two are not completely
overlapped it does suggest a difference.
- During the night, August and February temperature difference both show a
0.11°C difference, and the standard error of the mean overlaps, which means
that statistically there is no significance.
Implications
- With the threat of global warming on the rise, due to greenhouse gases,
it is possible that the effects of heat islands throughout the country will
become more extreme and severe; however, we can help prevent and combat this
problem.
- Here at Edgewood, we can further reduce the increased temperature by
creating more vegetative areas around building structures, and parking lots.
This idea can also be used in other, even larger areas throughout the
country to help reduce the effects of a heat island. Without
vegetative areas more carbon dioxide (greenhouse gases) will be released
into the atmosphere because the plants will not be there to consume it.
- Air conditioning is a problem for the environment because the warmer it
gets, people use more air conditioning. Air conditioners need energy,
and this energy comes from burning fossil fuels. The burning of fossil
fuels releases carbon dioxide into the atmosphere, which perpetuate the
cycle that causes global warming.
Conclusion
- A strong heat island effect does not occur on the Edgewood College
Campus, but there are still some indications of a partial heat island
effect.
- Since Edgewood College is such a small area, compared to what a
significant heat island would be (urban vs. rural), the results were not
expected. We thought the parking lot would be warmer than the rain
garden regardless of whether it was day or night. The results showed
that the parking lot was only warmer during the day.
- A better location for the rain garden temperature station would be near
a spring, or further into wooded areas and further away from building
structures.
- To expand upon this project, we recommend looking into past
Madison city temperatures to see how they compare to the parking lot and
rain garden temperatures.
- It would be interesting to find out how Edgewood would fall within a
larger heat island effect involving the urban Madison area, its suburbs, and
the country farmland surrounding it.
Edgewood
College Heat Island Effect Sustainability Report (PDF)
Acknowledgements
Heat Island Effect | U.S. EPA. (2009, February 20). Retrieved March 4, 2009,
from http://www.epa.gov/heatislands/index.htm
Heat Island Group Home Page. (2000, April 27). Retrieved March 4, 2009, from
http://eetd.lbl.gov/HeatIsland/
Heat island - Encyclopedia of Earth. (2008, October 31). Retrieved March 4,
2009, from http://www.eoearth.org/article/Heat_island
Lorman, Jim. Edgewood College Professor
Urban Heat Island Effect. (n.d.). Retrieved March 4, 2009, from
www.earthpledge.org/gr/urban-heat-island-effect
