This text is part of the special Research section: climate issues
Increasingly frequent and increasingly intense due to climate change, heat waves are hitting the country hard. In order to measure the vulnerability of the population and the effects of exposure to this meteorological phenomenon across Canada, a research team from the Department of Geography at Laval University launched a tool last May in the form of web mapping that is accessible to everyone.
Funded by the Canada Mortgage and Housing Corporation, this new interactive map of the vulnerability of the Canadian population to extreme heat waves was designed based on four indices: sensitivity, ability to cope, exposure and vulnerability.
“We evaluated urban heat islands by looking at the temperature difference between urban areas and vegetated areas. We can see that a person can live in a place where there is a 15 degree difference between their area and the surrounding region. It also allows us to see if there are islands of coolness nearby,” explains Nathalie Barrette, professor in the Department of Geography at Laval University and co-researcher of the project.
“Then we look at what generates the vulnerability. So if you live in an area where there is a sensitivity indicator that is high or low, and the ability to deal with it. There are all the places in which a person can take refuge when there are episodes of heat, such as public swimming pools, shopping centers,” adds the expert about the map, which makes it possible to observe 156 Canadian metropolitan regions and cities.
More concretely, this map can serve as a “support tool” for political decision-makers, for planning, town planning and public health professionals and for the general public. “If I am a political decision-maker and I have money to put, for example, into a greening project, that tells me which regions to prioritize,” explains the professor.
The effects of heat
“One of the things that struck me when we finished the tool is that we often associate heat waves and heatwaves with big cities. The result shows us [que] small and medium-sized towns are also affected, and they will be more and more affected,” underlines Mme Barrette.
The consequences on the health of people affected by heat islands or heat waves are multiple. “In terms of health, we know that there are cardio and respiratory diseases. We can also note an increase in violence, so there are consequences on mental health. Anyone who has conditions like diabetes or kidney failure is really at greater risk. Heatstroke is also one of the main causes of mortality during these episodes,” she lists.
To cushion the effects of these weather phenomena, short-term solutions exist, according to Nathalie Barrette. “One of the first measures that we can put in place […] is greening, to reduce heat islands. Whitening roofs and surfaces can also help. The idea is to make a place less impermeable,” says the professor.
This content was produced by the Special Publications team at Duty, relating to marketing. The writing of the Duty did not take part.