New post fire regrowth in the Adelaide Hills. February 2020. Image credit: Tanya Doody © CSIRO
What a difference a year can make!
At the end of 2019, south eastern Australia was experiencing dust storms and bushfires. Dust storms occur when strong winds blow over areas with low vegetation cover. By the end of 2020, the dust storms had stopped, and the fires had significantly decreased.
Dr John Leys, a visiting scientist with our Land and Water team, said the reduction in dust storm is due to an increase in areas with enough vegetation cover to control wind erosion.
“These are areas with more than 50 per cent vegetation cover,” John said.
Rapping interactive maps
We’re working with the National Landcare Program to produce monthly maps showing total vegetation cover. These are published on the RaPP site. This online tool provides time-series data on the vegetation and environmental conditions in Australia.
The figure below shows total vegetation cover in November 2019 to the left and in November 2020 to the right. The largest change in vegetation cover is on the slopes and plains of New South Wales and along the eastern border of South Australia. Areas with brown tones do not have enough vegetation cover to control wind erosion.
You can explore this RaPP map. Simply click and drag the circular symbol (slider) left or right to see more of the maps.
“In central New South Wales, for example, the area protected from wind erosion has increased from 42 per cent in November 2019 to 98 per cent in November 2020,” John said.
“Good rainfall in the last 12 months increased vegetation cover in November 2020.”
Vegetation and fire
Fire has a huge impact on vegetation cover. RaPP shows this clearly by comparing the months before and after a fire. The map below shows red polygons of indicative fire extent and here’s a detailed description of the map data.
You can further explore this map. Click and drag the circular symbol (slider) left or right to see more of the maps. Move the slider left to right to see the difference in the vegetation cover in the fire regions between February and November 2020.
Changing the month while looking at the fire area indicates when it was burnt. The colour changes from blue (high cover of more than 80 per cent) to white (moderate cover of about 50 per cent) post fire.
“For example, the area west of Coffs Harbour has low cover in September 2019. Further north the cover decreases in December 2019,” John said.
“Recovery of the vegetation cover can be seen in many areas by November 2020. However, high vegetation cover does not indicate the forest has fully recovered to pre-fire condition. It just means there are plants covering the ground.”