On a hot summer’s day in Ottawa, you can practically see the streets sizzling.
The temperature increase in urban areas due to heat radiating off concrete is known as the heat-island effect. Ottawa Public Health, using satellite imagery, has started a project to map parts of the city that feel the worst of it. Buildings, sidewalks and roads radiate heat much more than green areas, so temperatures can climb by up to three degrees Celsius in those places during the day and 12 degrees Celsius at night.
University of Ottawa graduate Peter Keizer is working on the mapping project. In addition to identifying hot spots in town, he’s looking at what other cities have done, and at what solutions there are for city planning in the future.
“We’re wanting to know how the most vulnerable populations are coping,” says Martha Robinson of Ottawa Public Health. She also chairs the city’s extreme weather committee.
The project will identify the hot spots, which will then be overlaid with information about potentially vulnerable people within the city. Kids, the elderly and homeless people are most at risk during a heat wave and Ottawa Public Health hopes the project will help.
“The second part of the project is going to look at some specific parks to see how they can be made cooler, looking at what types of vegetation might work well in a park with lots of seniors, that kind of thing,” says Robinson.
Dundonald Park on Somerset Avenue is one area Ottawa Public Health hopes to improve.
Robinson noted rooftop gardens, lighter-coloured building materials and constructing parking lots underground as long-term methods to reduce the heat-island effect, as well as simpler things such as water fountains, shaded benches and splash pads as immediate ways for residents to cool off in public parks.
Bonnie Mabee, chair of the Centretown Citizens Community Association’s trees and green-space committee, says the issues need to be looked at more broadly.
“I’m not sure, to be quite honest, that (OPH) have a lot of leeway as to what they can do about it,” she says.
Hot spots could probably already be identified, Mabee noted, but solutions are what matters.
“Can you make sure that somebody can go through some of those apartments to help some of these elderly people if there’s a heat wave? Are we making sure we’re pushing the city to do more greening of buildings and reducing energy?”
Mabee identified building design as the number one solution, noting Vancouver is way ahead of Ottawa in having “greener” buildings that incorporate water- and energy-efficient technologies and sustainable building materials to reduce environmental impact.
Association vice-president Rob Dekker says there’s a delicate balance between developers, the city and the community to finding an equilibrium between laying down more concrete or dealing with the heat island effect.
“With rising property values in Centretown, a decent-sized plot for a park is going to cost $1 million or more for the city to purchase, and that’s before greenscaping and putting in things like benches. It’s going to come down to whatever formula the city can come up with,” Dekker says.
“I think there has to be a political will. . . to do that and we’d like to see from (Coun. Diane Holmes) and through the planning and environment committees some political will demonstrated to have more greenspace added downtown.”