Friday 28 August 2020

Satellite imagery reveals, in precise detail, extent of NSW bushfire destruction across Black Summer.

 Extract from ABC News

a composite image showing a green mountain scapes against burnt bushland
Katoomba in the Blue Mountains, before and after the Black Summer bushfires.(Supplied: Geospatial Intelligence)

Satellites have revealed the scale of the destruction during the Black Summer, showing for the first time the entirety of the aftermath of the NSW bushfires in one image.

Last year, Australian aerial analysis company Geospatial Intelligence was contracted by the NSW Government to capture before-and-after images of the bushfire season which burnt more than 5.5 million hectares across the state.

The result is more than 100 terabytes of landscape photos taken over a six-month period, showing the results of fire tornadoes after they ripped through world heritage national parks and coastal villages.

Geospatial Intelligence chief executive Rob Coorey said the photos are being used by the State Government to help track regeneration, the impact of drought on fire intensity and land management.

Unlike other services, the company utilises 1.5 metres per pixel (px) on their cameras, as opposed to the 30-250 metres/px typically taken by Sentinel satellites, which produce much of what we see on Google Maps.

the state of NSW from the sky

NSW months before devastating bushfires burnt through 5.5 million hectares last year.(Supplied: Geospatial Intelligence)the state of NSW from the sky, the land is scarred and burnt
The fire-scarred landscape after the NSW summer bushfires.(Supplied: Geospatial Intelligence)

The higher image fidelity allows researchers and firefighters to examine the landscape in more precise detail.

"The fire around the Blue Mountains," Mr Coorey said as an example, "was extremely intense … to the point where you could actually see how the fire tornadoes have left scarring across the land."

"You can almost see the pattern for when the wind changes with these tornadoes.

"It'll be going from north-west to south-east and then maybe an easterly direction."a composite image showing a green mountain scapes against burnt bushland

Mount Wilson, near where a backburn started the Grose Valley Fire in December.(Supplied: Geospatial Intelligence)

A snapshot taken over Mogo on the NSW South Coast, which was flattened over New Year's Eve, shows the charred bushland surrounding the town.

However, green patches within the town boundaries and the land running along Mogo Creek also reveal how intense rainfall has helped with land regeneration.

Mr Coorey said high-resolution aerial imagery is not a replacement for traditional mapping methods used by firefighters, but could complement aircraft used to survey land and flames.a composite image of an area showing it before and after it was burnt

Mogo on the South Coast, before and after the New Year's Eve fires.(Supplied: Geospatial Intelligence)

"It has a very, very high value in the pre-fire planning periods, so this period now coming up into the fire season," he said.

"It's not one panacea which is going to be the solution to everything.

"But it has a really great role to play and is, in actual fact, very cost-effective when you're looking at the sorts of things the [Government] uses it for."

Spatial Services, a surveying department operated by the Department of Customer Service NSW, is already utilising these images to prepare against future bushfire seasons, which a recent NSW inquiry said could be intense, if not worse than the 2019 season just past.

It has used drones, satellites and other remote control aircraft to analyse fuel loads and help with environmental planning and emergency management.

"Post-fire applications include burn-extent analysis, koala post-fire occupancy analysis, vegetation dieback research, forest monitoring programs and to monitor urban recovery and reconstruction programs," a Spatial Services spokesperson said.

"In response to the NSW Independent Bushfire Inquiry recommendations, the key issues for our sector are coordination and rationalisation of the broad range of imagery sources and providers.

"Our focus will be on ensuring there are automated processing pipelines that deliver these data in as near to real-time as possible to support emergency services in prevention, preparedness, response and recovery."

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