Heat Waves & Vulnerability App Puts Mapping at the Centre

The Department of Geography at Laval University launched an online mapping app to explore the intersection of vulnerable communities and extreme heat waves in major Canadian cities. The app currently maps 156 census areas using dasymetric mapping to exclude uninhabited areas, and more accurately analyze the population’s exposure and vulnerability.

The project calculated and processed four indices: Exposure, Sensitivity, Coping Capacity, and Vulnerability, to uncover the areas where populations are exposed to heat waves. The geographic layers were integrated into an ArcGIS web app to allow users to interact and explore the data from a map. Laval University has made the geodatabase available to the public.

The description of Laval’s app reads: “In our view, such tools give the public meaningful and context-appropriate information for a geographic analysis of the vulnerability of communities living in Canada’s major urban centres. With this information, public authorities will be better equipped to deal with heat waves and the health effects they can cause.”

“To prepare for the multi-faceted challenges that come with heat waves, we need up-to-date, high resolution data models that help simplify complex information, says Alexander Watts, PhD, Public Health Industry Manager, Esri Canada. “Laval’s new heat wave indices represent a huge opportunity for emergency preparedness teams across the country to make localized and effective decisions.”

Indeed, Canada has faced the issue of heat waves. In 2021, the province of British Columbia experienced a heat dome in which the village of Lytton recorded a temperature of 49.6 Celsius in a single day and hundreds of heat-related deaths. Subsequently, the entire village burned in a wildfire.

“By taking a geographic approach, diverse stakeholders involved in heat emergency preparedness can collaborate even better because maps help diverse teams speak the same language at a very local level and ask strategic questions, such as: Which specific neighbourhoods should be prioritized? Where should we build additional infrastructure in those neighbourhoods? Which community centres can we engage with ahead of time?” says Alexander.

Increased health problems due to heat waves are exacerbated for those living in exposed areas—areas with low soil permeability, few greenspaces, poor air circulation, densely built buildings, etc., and even more so for vulnerable people who may not be able to protect themselves.

Laval acknowledged that the impact of heat waves on individuals depends predominantly on their access to resources like adequate housing. “How we frame the conversation of adequate housing in this instance should consider not only the physical living space, but also the overall building design, the surrounding amenities, and current and former zoning regulations and development guidelines, says Linzey Bedard, Community Design Solutions Manager, Esri Canada. “Currently and historically, our standards for adequate housing have been too low and unfortunately this will disproportionately affect vulnerable populations if we continue to avoid making necessary changes.”

Knowing what changes are required involves utilizing geodesign as a strategy in community planning. Geodesign fuses planning with environmental data and value-based information within a technology platform to help government make better-informed decisions. “We know trees, public greenspaces, and robust landscaping along streets, in plazas, and in courtyards can help to mitigate urban heat. Historically, neighbourhoods with predominantly vulnerable and marginalized populations have been excluded from these types of heat mitigating amenities, says Linzey. “A critical first step for cities would be a detailed inventory of trees and greenspaces and a spatial analysis of their geographic distribution.”

As stated in the Laval’s app description, facilitating these types of changes is not only the responsibility of local government. For example, minimum standards for adequate housing may be defined by regional or provincial government. Different levels of government must work together to develop strategies and equitable policy. Laval has demonstrated that mapping can be that common ground.