The dust days aren’t over

By Claire Harris, Sarah Frazer

22 November 2018

4 minute read

NSW Health Services recommend limiting time outdoors during dust storms. Photo: Tago Fabic

Currently, there’s a line of dust more than 500km long sweeping across the Victorian border, through Canberra and up to Queensland. This dust is more than just annoying – it can be bad for our health, ecosystems, and the built environment.

If you’re being impacted by a dust storm, please take advice from your local authorities for health warnings. NSW.

Video courtesy from BoM, generated using JMA’s Himawari satellite.

The current drought has stripped a lot of ground cover across eastern Australia, leaving wide ranges of dry, exposed dirt that pose an increased dust storm risk. To predict the risks of dust storms, we need to marry weather forecasts with the potential dust sources across the country and see if they are going to meet up.

Few of us could forget the dust storm in September 2009, which famously blanketed Sydney in a bright orange hue. The urban costs of this storm were estimated at $300 million alone.

Red haze enveloped Sydney Harbour Bridge during a dust storm on September 23, 2009. Photo: Amber Hooper

Predicting dust storms

Dr Juan Pablo Guerschman, one of our research scientists, has been working with colleagues in the Australian, state and territory governments to deliver Australia’s dust and ground cover monitoring expertise and is supported by the Australian Government’s National Landcare Programme.

“Using satellite products we can estimate landscape types of interest across the Australian continent, like the proportion of the land that is covered by vegetation – either green or dry – or that is bare soil.”

“When there’s windy weather and low ground cover, it means that there’s a risk of dust storms and erosion of our soil, and so particularly in spring and summer we know that our data products will be in demand.”

Every eight days a new image comes through from a US satellite called MODIS. Juan and his team have developed a system that takes that satellite information, runs it through mathematical calculations and delivers information about groundcover through the Rangeland and Pasture Productivity Map. This is then picked up by data users such as the Community DustWatch program to assess where there might be sources of dust if the wind is strong enough.

The DustWatch program tracks wind erosion across Australia and produces a range of maps and products for use by governments and land managers and to warn agencies monitoring air quality of incoming dust storms.

In many parts of Western NSW, vegetation levels are the lowest they’d been since Juan and his team started capturing images of the cover in 2001. While the lack of vegetation is not as extreme as in 2009, the most arid part of the outback – where most of the dust comes from – is in much lower condition than average, so this event was expected which allowed for some advance warning to impacted communities. You can explore the image here.

The current conditions aren’t as severe as those from the dust storm of 2009 – but can still cause strife.

Not the ideal white Christmas

Dust has settled in a blanket over Sydney. Photo: Kenny Smith.

Some additional analysis by the Dustwatch project suggests that the vegetation cover this coming summer may plummet to the low levels observed in previous droughts.

The online tool helps regional NRM organisations, industries and policy makers to inform them of ground cover change, and will provide the basis for Department of Agriculture and Water Resources’ reporting on improvements in resource condition at the national level.

This research can do more than just predict potential dust storms- across the world, researchers can link this land cover information with biomass and animal production models to understand how we can sustainably produce more food.

If you’re being impacted by a dust storm, please take advice from your local authorities for health warnings. NSW.