Operations manager Rob Hands surveys the damage done during the Christchurch's Port Hills fire. Photo / Pool
The likelihood of a blaze akin to the Port Hills fire happening again is increased at the moment due to dry conditions - but human intervention is still the driving
factor of these fires starting.
Fire blackened more than 650ha in Christchurch’s Port Hills over the past week. The blaze initially burned uncontrollably for more than a day, before fire crews were able to contain it.
More than 100 homes were evacuated, with one woman’s home being destroyed in the blaze.
Dr Nathaneal Melia, director of climate change consultancy Climate Prescience, has been researching New Zealand’s fire risk for several years. He told The Front Page, the Herald’s daily news podcast, that the incredibly dry vegetation and trees in the Port Hills, combined with hot, El Nino conditions would have fuelled the fire.
He said the topography of the Port Hills makes it a tinderbox.
“The most important thing to get a fire going and of a decent size is that wind, that dry wind, because once you get a spark, a few embers, that fire then spreads.
“And particularly somewhere like the Port Hills, where you’ve got quite steep slopes with a lot of vegetation, those flames, instead of just going straight up and burning whatever they happen to catch alight, they go up because it’s fire, and then they get bent diagonal. And when that happens, they then ignite the piece of vegetation next to them. And that just carries on.”
As part of Melia’s research, he found that parts of New Zealand can experience the incredibly dry conditions similar to what caused Australia’s ‘Black Summer’ wildfires in 2019 - 2020, but those areas rarely have dense vegetation to lead to fires.
And while climate change will make these dry conditions worse, Melia said that New Zealand does not get the ‘dry lightning’ phenomenon that sparks fires in other parts of the world. Instead, fires here are almost always the result of human activity.
“That can be arson on purpose. It can be something as mundane as normal agricultural activities, like trilling the ground with a metal blade that strikes a flint, and that spark then goes into bush and ignites the landscape. That’s what happened in the Pigeon Valley fire, [in] Nelson a few years ago.”
He said the Port Hills has a decent fire danger but not the highest in the country, but the “rural-urban interface” is more of a problem. “That’s where people are living and conducting activities around this fringe, where the countryside meets people, and that’s where you’re getting fires.”
Listen to the full episode to hear more about New Zealand’s current and future fire risk - and University of Auckland lecturer in Urban Planning, Dr Iresh Jayawardena, joins to discuss if fire risk is something we need to start considering with building new homes.
The Front Page is a daily news podcast from the New Zealand Herald, available to listen to every weekday from 5am. This episode was presented by Chelsea Daniels, an Auckland-based journalist with a background in world news and crime/justice reporting who joined Newstalk ZB in 2016.
You can follow the podcast at iHeartRadio, Apple Podcasts, Spotify, or wherever you get your podcasts.
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