How can GIS help mitigate the effects of extreme heat on public health?
With Canada experiencing record breaking heat this summer, many people are worried about how they can stay safe, and public health departments are concerned about the negative toll the heat will take on Canadians. Read on to learn about different ways GIS can be leveraged by public health and local governments to mitigate adverse outcomes caused by extreme heat events.
It is estimated that over 700 sudden deaths occurred between the week of June 25th – July 1st when British Columbia (BC) experienced extreme temperatures, with an all-time Canadian high temperature of 49.4 °C set in the village of Lytton, BC. These extreme heat events put individuals with underlying health conditions at an increased risk of death and directly contributes to mortality among individuals who are over-exposed to heat. The resulting increased demand on emergency services such as ambulances can overburden the system and delay critical care to people suffering from non-heat related emergencies. Events like the one in Lytton and BC at large are not isolated to one part of the country and can affect every region from the West Coast to the Maritimes.
There are several ways geographic information system (GIS) tools can be leveraged by public health and local governments to help plan for and mitigate adverse outcomes caused by extreme heat events. A GIS interface like ArcGIS Online allows users to readily visualize real-time weather data, vulnerable population groups, and emergency infrastructure. Integrating various data sets into a single interface allows decision makers to locate populations that are vulnerable to extreme heat and see if they have infrastructure such as cooling centers or water stations near the people who will need them most.
Environment Canada web map showing temperatures across Southern Ontario.
The two layers in the web map above show current weather readings from Environment Canada weather stations and a 2.5-kilometer resolution surface of current air temperature. Both layers are provided as a web mapping service (WMS) from Environment Canada’s Geomet platform. Visualizing these layers allows users to identify specific geographic areas more likely to be affected by the highest temperatures.
Map of southern Ontario showing heat alerts extending from Windsor-Essex to Toronto and York Regions.
Alerts from Environment Canada can also be integrated into a GIS interface. This layer provides users with an authoritative source on the type, location, and estimated duration of extreme weather events. Knowing how long a heat event is expected to last is crucial because the longer the extreme heat lasts the more physiological stress gets placed on the people experiencing it.
Map of southern Ontario showing layer with material deprivation mapped out at the dissemination area (DA) level of geography.
Furthermore, socio-economic data such as the material deprivation index can help locate vulnerable populations that are at an increased risk of negative health outcomes during an extreme heat event. Material deprivation involves deprivation of the goods and conveniences that are part of modern life, such as adequate housing, possession of a car, access to highspeed internet, or a neighborhood with recreational areas. Social deprivation refers to a fragile social network, starting with the family and encompassing the community. It is characterized by individuals living alone, being a lone parent and being separated, divorced or widowed.
Those who are more vulnerable or marginalized may not have air conditioning to cool their homes or vehicles. Knowing where these populations are can help simplify public health mitigation strategies to target where cooling centers should be placed to support those communities that need them most.
Integrating data in ArcGIS Online can empower local governments and public health, and mitigate the adverse health impacts of extreme heat events. Officials can locate their vulnerable populations and set up interventions to assist them with overcoming the stress of extreme heat. GIS-centric interventions can help mitigate the number of people suffering from heat-related illness and avoid overburdening the health care system.
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This post was translated to French and can be viewed here.