Identifying areas of greatest heat vulnerability and lowest tree canopy cover in Montreal, QC using an index model and MCE in GIS
Extreme heat events have significant health consequences for urban populations. Heat-related illness disproportionately affects vulnerable members of the urban community, including infants and elderly people, racial minorities, and people who are socially isolated or receive a low-income. These vulnerable populations intersect and vary spatially within the urban environment. Spatial analysis of these populations can help identify areas where heat vulnerability is greatest, and where heat-mitigation measures will be most beneficial.
Urban areas high in impermeable surfaces experience excess heat retention and higher average temperatures during heat events. Neighbourhood tree-cover and public cooling centers can mitigate extreme heat and help residents maintain cooler body temperatures. Extreme heat events are projected to increase with climate change, intensifying heat-related health concerns in urban areas. This problem demands municipal-level planning to increase heat-mitigating tree-cover in vulnerable areas and minimize heat-related illness during extreme heat events.
This study makes use of diverse heat-vulnerability data to identify high priority census tracts for improved tree-cover in the City of Montreal. Census variables include age, income, education-level, ethnicity, social isolation and housing structure. Proximity to public cooling facilities and LiDAR-derived canopy-cover data are also used to identify census tracts with limited heat-mitigation capacity.
A spatial overlay of nine vulnerability variables identifies census tracts in the City of Montreal where tree-coverage should increase. Ten high-priority tracts are identified; these have the greatest presence of intersecting vulnerability factors, including minimal tree-cover. Hot-spot analysis identifies three neighbourhoods where the ten high-priority census tracts are clustered.