Helping Canadian communities reduce urban heat islands

Children playing in Captain John Wilson Park in Windsor, Ontario. This park has been retrofitted with a splash pad, gazebo, water fountains and trees. Photo courtesy of City of Windsor

By Gregory R.A. Richardson and Jay Storfer

The term ‘urban heat island’ (UHI) describes built up areas that are hotter than the surrounding countryside. UHIs usually occur in cities where, under the right climate conditions, built surfaces like roofs, paved roads and parking lots can absorb large quantities of radiant heat from the sun resulting in increases in both surface and air temperatures (EPA 2008). Studies have found the average air temperature in cities with one million people or more is generally in the range of 1°C to 3°C warmer than the surrounding countryside and can be as high as 12°C warmer in places within a city (Oke 1997).

UHIs can magnify health impacts during heat waves as sustained higher air temperatures have been linked to increases in heat-related illnesses and death. Climate change, which is projected to increase the frequency, intensity and duration of heat waves in many parts of Canada, is expected to place additional pressure on the health of Canadians (Casati et al. 2013). Key urban planning measures to reduce UHIs include an expansion of vegetation cover by planting trees and shrubs and an increase in surface reflectivity by installing more reflective roofs, pavements and building facades.

Since 2008, Health Canada has been leading a multi-pronged initiative to enhance community and individual resiliency to extreme heat events. Much of Health Canada’s heat initiative has focused on public health preparedness activities, such as supporting health authorities with implementing evidence-based heat alert and response systems. This paper provides an overview of Health Canada’s efforts in developing information and guidance materials to help communities adapt to extreme heat through the reduction of the UHI effect (Richardson et al. 2015).

A four pillar approach to helping communities reduce UHIs

Health Canada has implemented the following four pillar approach to helping communities in Canada reduce UHIs:

1. Decision-support tools
Health Canada has supported the development or translation to English of the following decision-support tools (e.g. surface and air temperature maps and design guidelines).

1. Peel Priority Tree Planting Tool
(Regional Municipality of Peel)
An interactive tool that can be used to prioritize areas for future tree planting in Peel Region based on a range of environmental, public health and socio-economic benefits afforded by the urban forest (Executive summary | Full report).
2. Heat-Health Mapping Portal
An online mapping portal (i.e. Google maps interface) with maps of the land surface temperature and vulnerable populations for all of southern Québec.
3. UHI Parking Lot Design Guidelines
(Bureau de Normalisation du Québec and le consortium Ouranos)
A parking lot design standard that provides practical guidance on how to mitigate urban heat islands and reduce storm water run-off volumes.
4. Climbing Plants Guide
(Montréal Urban Ecology Centre)
A practical guide to planting and maintaining climbing plants.
5. Surface Temperature Maps for Cities in Ontario (Beta)
(Kingston, Frontenac and Lennox & Addington Public Health)
An online mapping portal with land surface temperature maps for major cities across Ontario.

 

2. Research
Health Canada has supported research to expand knowledge of the health impacts of UHIs in the Canadian context. Research projects include a study to measure indoor thermal conditions in 56 apartments in Montréal (Mirzaei et al. 2012) and the installation of a network of environmental heat monitors in cities across Canada.

3. Outreach and engagement
Health Canada has supported outreach and engagement initiatives that help raise awareness about UHIs and increase capacity among stakeholders to take action. Notably, in 2013, Health Canada launched its Cool Communities Webinar Series to showcase innovative community-level initiatives that help reduce UHI effects and improve indoor and outdoor thermal comfort.

4. Demonstration projects
Health Canada has worked with six pilot communities (Ottawa, Windsor, Peel Region, York Region, London and Vancouver) to identify the local causes of UHIs and to implement innovative approaches to reduce heat-health impacts (see City of Windsor case study below).

Case study: Improving thermal comfort in Windsor’s parks and playgrounds

In 2012, Health Canada supported the City of Windsor – Canada’s southernmost and warmest city – with an assessment of UHIs (De Carolis 2012). A key finding from this report was the City’s green spaces (i.e. parks, playgrounds and playing fields) were becoming hot and uncomfortable on many summer days. This was a concern for City officials as their public messaging on extreme heat recommended individuals to seek out green spaces as a potential option for cooling down. Subsequently, the city conducted a second study in 2013 to investigate the thermal comfort in six of Windsor’s parks and playgrounds (Blanchard 2013). Using satellite imagery and infrared cameras, the City discovered just how hot urban parks can get. Researchers recorded rubber mats under playground equipment reaching temperatures of up to 72°C – hot enough to scald. The report recommended various actions, including developing shade guidelines and changes to the design of parks and playground to add cool features such as water fountains, trees, lighter coloured rubber mats, splash pads and shade structures. As a result of Health Canada’s collaboration, the City of Windsor has retrofitted five parks with cool design features.

Key lessons learned

The majority of research conducted on UHIs has occurred outside of Canada and in warmer climates. Health Canada’s research and demonstration projects, however, have produced results and lessons learned that are applicable for the Canadian context. Health Canada found that maps are an essential tool to identify the location of UHIs and to help communities to prioritize where to take action. A second finding has been the importance of project champions and support from senior management and city councillors. For example, in Windsor, the City’s Supervisor for Environmental Sustainability and the Manager of Parks Development championed the projects and ensured that policy and design advice was translated into action on the ground. In addition, Windsor City Council reviewed and endorsed each stage of the project.

Conclusion

This article has focused primarily on Health Canada’s efforts in providing information and guidance to help communities reduce UHIs as part of a broader approach to adapt to the health impacts of extreme heat. However, it is important to note that other organizations and levels of government in Canada have been instrumental in reducing UHIs. For example, between 2009 and 2013, the Government of Québec administered a $14 million grant program which provided funds to support pilot projects that reduce UHIs. City and regional governments have also implemented a wide range of actions from mandatory reflective roof bylaws in the Montréal borough of Rosemont–La Petite-Patrie (Richardson 2014), to green parking lot design standards in Toronto (City of Toronto 2013) and heat-health vulnerability maps in Vancouver (City of Vancouver 2012). Moving forward Health Canada plans to continue sharing information and lessons learned to support Canadian communities with reducing the health impacts from urban heat islands.

More resourcesOutdoor PLAYbook: Featuring innovation in resilient playground design
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Short biographies:

Gregory Richardson (MCIP, RPP) is a Policy Analyst in the Climate Change and Innovation Bureau at Health Canada (Government of Canada) where he works with Canadian communities to reduce the urban heat island effect and improve indoor and outdoor thermal comfort.

Jay Storfer is a Senior Policy Advisor at Natural Resources Canada. From 2009 to 2015, Jay was the team lead for Health Canada’s efforts in helping communities reduce urban heat islands.

References

Blanchard, S. (2013). Improving Thermal Comfort in Windsor, ON; Assessing Urban Parks and Playgrounds. Windsor, Ontario: City of Windsor. Retrieved from http://www.citywindsor.ca/residents/environment/Environmental-Master-Plan/Documents/Improving%20Thermal%20Comfort%20in%20Parks_no%20appendices.pdfCasati, B., Yagouti, A., & Chaumont, D. (2013). Regional Climate Projections of Extreme Heat Events in Nine Pilot Canadian Communities for Public Health Planning. Journal of Applied Meteorology and Climatology, 130725113712005

City of Toronto. (2013). Design Guidelines for “Greening” Surface Parking Lots. Toronto, ON: City of Toronto. Retrieved from http://www1.toronto.ca/city_of_toronto/city_planning/urban_design/files/pdf/greening_p-lot_guidelines_jan2013.pdf

City of Vancouver. (2012). Climate Change Adaptation Strategy. Vancouver, BC: City of Vancouver. Retrieved from http://vancouver.ca/files/cov/Vancouver-Climate-Change-Adaptation-Strategy-2012-11-07.pdf

De Carolis, L. (2012). The Urban Heat Island Effect in Windsor, ON: An Assessment of Vulnerability and Mitigation Strategies. Windsor, Ontario: City of Windsor. Retrieved from http://www.citywindsor.ca/residents/environment/environmental-master-plan/documents/urban%20heat%20island%20report%20%282012%29.pdf

Environmental Protection Agency. (2008). Reducing Urban Heat Islands: Compendium of Strategies. Washington, D.C. Retrieved from http://www.epa.gov/heatislands/resources/compendium.htm

Mirzaei, P. A., Haghighat, F., Nakhaie, A. A., Yagouti, A., Giguère, M., Keusseyan, R., & Coman, A. (2012). Indoor thermal condition in urban heat Island – Development of a predictive tool. Building and Environment, 57, 7–17.

Oke, T. R. (1997). Urban climates and global environmental change. In R. D. Thompson & A. Perry (Eds.), Applied climatology (pp. 273–287). London, UK.: Routledge.

Richardson, G. R. A. (2014). Measures to reduce the urban heat island effect in Rosemont–La Petite-Patrie. Ottawa, ON: Natural Resources Canada. Retrieved from http://www.nrcan.gc.ca/sites/www.nrcan.gc.ca/files/earthsciences/pdf/mun/pdf/13-0616-Rosemont%20Case%20Study_e.pdf

Richardson, G. R. A., Storfer, J., & Yagouti, A. (2015). Helping Canadian communities reduce urban heat islands. Presented at the 52nd International Making Cities Livable Conference, Bristol, UK.

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