Some of Canberra’s inner-city suburbs are the most heat-vulnerable in the territory, despite the benefits of their leafy tree-lined streets, new research shows.
Research by Monash University’s Co-operative Research Centre for Water Sensitive Cities found the Canberra postcodes most at risk from heatwaves are 2601, 2602, 2605 and 2606.
Those postcodes include the verdant suburbs of Curtin, Ainslie and Garran, as well as most of Civic and Woden town centres.
Street trees on Batman Street, Braddon. Photo: Rohan Thomson
The findings come after Australian National University research in January, which showed Canberra’s mostly-treeless outer suburbs were likely to be up to seven degrees hotter in summer than those with more established trees - such as those inner suburbs.
Monash University program leader professor Nigel Tapper said that while they had taken into account the temperature benefits of the trees, other factors were also considered to determine how vulnerable an area was to heat.
These included the age of residents, socio-economic status, housing density and access to emergency services.
‘‘You might have a very wealthy community living in a relatively leafy suburb but it might be vulnerable because of the large number of old people in the suburb. What our index does is it combines all those variables,’’ he said.
The findings are particularly relevant given Canberra’s recent spate for extreme heatwaves, which included the city’s longest streak of days above 37 degrees on record.
Research by ANU academic Liz Hanna had previously confirmed international studies linking temperature variation in suburbs to urban design and foliage.
In that study of 21 Canberra suburbs, researchers found temperatures could vary by as much as 7.5 degrees between treeless postcodes and those with more trees.
Professor Tapper’s website also tracked the number of ambulance callouts during days over 33 degrees in the ACT, between August 2004 and April 2011.
Dickson, Charnwood, Lyneham and Holt were some of the suburbs that used ambulances the most during times of hot weather.
‘‘Work that we’ve done has shown that for all Australian capital cities there are clearly defined temperature thresholds above which people become sick and or die,’’ he said.
He said Canberra recorded increasing mortality issues resulting from heatwaves at slightly lower temperatures than other capital cities.
Professor Tapper said he hoped his research would help inform emergency services so they could better prepare for extreme weather events.