Methods

HealthyPlan.City combines built environment datasets from different sources with demographic datasets from the Canadian Census to present a picture of environmental equity in urban areas for over 150 cities across Canada. Nationally, we use an urban zone that includes all Census areas identified by Statistics Canada as being within population centres with 1,000 or more people.

We also include rural areas within 5 km of population centres. The urban zone used in   HealthyPlan.City is home to 31,862,300 people, or 91% of Canada's population.

 City boundaries are based on Statistics Canada Census Metropolitan Area (CMA) boundaries.

Demographic Data

Demographic data for vulnerable populations come from the 2016 Census of Canada, and are provided for dissemination areas. A dissemination area is a small area composed of one or more neighbouring dissemination blocks, which are the smallest reporting areas available for demographic data in Canada. They typically represent a street block in urban areas, but can be larger in suburban areas. We downscale the dissemination area data by assigning the percentage of each vulnerable population group in each dissemination area to all the dissemination blocks within. The dissemination blocks data come with total population, so we can calculate the number and percentage of people in each vulnerable population group that live in every dissemination block.

Built Environment Data

All built environment datasets are prepared as 100m resolution surfaces for all urban areas in Canada. We then extract the data value from the surface at the location of the geographic centre of every dissemination block.

HEAT ISLANDS: LAND SURFACE TEMPERATURE AND TREE CANOPY

Heat islands occur in cities primarily due to large areas of paved surfaces (including rooftops of large commercial buildings) that absorb heat during the day and radiate it out during the night. Tree canopy provides shade and keeps surfaces cooler. HealthyPlan.City includes datasets for:

  • Average land surface temperature from May - September 2019
  • Percentage of tree canopy cover in 2015.

DATA SOURCES:

  • Land surface temperature: Derived from LandSat 8 data in Google Earth Engine using an adapted code shared on StackExchange by Edwin Osei, April 22, 2020.
  • Tree canopy cover: The Landsat Vegetation Continuous Fields (VCF) tree cover layer, which estimates the percentage of horizontal ground in each 30m pixel covered by woody vegetation greater than 5 metres in height was acquired via Google Earth Engine for 2015 and resampled to 100m.

Equity Priority

The percentages of vulnerable populations and the values for the built environment factors for all dissemination blocks within a city, defined by its CMA boundary, are ranked from 1 to 10, with 1 being the lowest 10% of the values (i.e. low percentage of vulnerable population group or the lowest levels of beneficial environment), and 10 being the highest 10% of the values (i.e. highest percentage of vulnerable population group or the highest levels of beneficial environment).

Equity Priority is assigned by combining the vulnerable population ranks > 5 (higher percentages of vulnerable populations) and the built environment ranks < 6 (lower levels of beneficial environments), as shown in the Equity Priority matrix below. In these locations, vulnerable demographic groups make up a greater proportion of the population, but experience fewer benefits or more risk from the built environment relative to the median. Darker shades of red are used to show higher equity priorities.