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January Recap - Carol Moogk-Soulis - Heat Islands by swp38119


									Carol Moogk-Soulis — Schoolyard Heat Islands: A Case Study in the City of Waterloo

Recap by Janet Ozaruk and Michael Frind

Carol Moogk-Soulis’s interest in the concept of heat islands was sparked when her child first
began attending school. She found that during recess the youngsters were not playing the active
games that she remembered from her youth, but were instead seeking shelter against the school
building, away from the hot and dusty playground. This observation turned into a concern
regarding the lack of play and its possible resulting impacts on children’s development.

Looking into the possibility of planting a few trees in the school yard, Carol found no policies
regarding the incorporation of trees into schoolyard design, nor for the care of such trees. This
led to the determination to quantify the benefits of trees and justify the planting of them in

To identify and quantify heat islands, Carol turned to NASA-developed satellite technology.
The satellite images provided a quantifiable thermal band and provided a better indicator than
thermal sensors buried in the soil. Focussing on imagery of Waterloo, land types were classified
into the following categories: high density urban, low density urban, grassland, cropland, forest,
and water. A temperature profile of the area was then developed in cross-section. It was found
that surface temperature readings taken during the morning recess period averaged 47C for
urban areas, while the temperature of the 15 schoolyards examined ranged from 48.4C to 55C.

The excessive heat associated with the schoolyards could be attributed to three factors: the
steel/tar and chip roofs; the mowed turf-grass; and the asphalted parking lots, play areas, and
portable classroom pads.

Carol chose Mary Johnson Public School for further study. Subsequent temperature sampling
taken during the morning recess in indicated an air temperature of 27C at the University of
Waterloo weather station, a shaded surface temperature at Mary Johnson School of 32C, and a
near-surface (head level of the average child) temperature of 43C at the school. It was also
noted that the lack of shade affected the air conditioning utilities bill, as the air intakes located on
the building roof drew in superheated air for cooling. On occasion, portables needed to be
abandoned as they were too hot inside to conduct classes.

Neighbouring houses were also affected. An examination of temperature profiles across the area
indicated that the heat conducted from the schoolyard was still felt 150 m away.
Clearly, if the heat-island effects around the schoolyards could be reduced, a reduction in both
urban heat and smog levels would result. Mitigation of the heat island effect could be
accomplished in two ways: increase heat reflection through appropriate building materials
(which not always possible in existing buildings and yards), and increase shade to prevent the
sun from striking the surface in the first place.

The benefits of planting shade trees throughout schoolyards include a decrease in shaded surface
temperatures of up to 25C, a decrease in shaded air temperatures of up to 10C, a decrease in
cooling costs associated with building operation, a decrease in radiant and convective heat gains
to neighbouring properties up to 80 metres distant, and contribution to overall city cooling by

In 1990, various plantings were carried out in the Mary Johnson schoolyard, with the emphasis
on creating a habitat link between woodlots. The trees have since matured to provide a
welcoming environment; however, temperature calculations have not been conducted due to a
lack of more recent satellite imagery of the area.

It was noted that the resources in terms of trees and labour are available to turn a hostile
schoolyard environment into one that encourages play and active learning. In spite of this,
policies are still needed to protect all of our urban trees.

Carol’s background incorporates both occupational therapy and engineering. She is continuing
her research on the heat-island theme by attempting to correlate negative behaviour at schools
with increased environmental temperatures, and also to correlate carbon dioxide levels in schools
with heat levels and how they relate to academic performance. (A detailed write-up of her
findings is available in the proceedings from the Canadian Urban Forest Conference, Markham

Thanks to Carol Moogk-Soulis for an eye-opening investigation into an often-overlooked aspect
of our urban environment.

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