Understanding fire history

Understanding the history of fires that have occurred on country you are managing is very important. It helps guide your understanding of areas that are burning too much or to identify a country that maybe needs a fire. Helps you to work towards developing healthy country and by guiding your burning strategy. Skip to video.

We will use the NAFI interface to download some of the fire history data so we can better understand whats going on. By downloading the data we have more flexibility to change colours and to show only areas we are interested in.

These data are also included in the data folder.

The first data we will look at is the fire frequency from the year 2000 to 2019. This shows the number of times over that twenty year period that a place a been burnt. Find the file “FF_2000_19_gda94.tif” file in the 250m pixel 2000-2019_Long Term Fire Frequency_Image File folder. Has the folder describes this is raster data were each pixel is 250 x 250 meters across and includes fires from 2000-2019.

Double click on this layer to show it in the map window.

It will open the map for all of northen Australia.

To show what the colours mean display the legend by click onthe little arrow next to the layer in the layers tab:

The numbers are the number of times a place has been burnt and the colours are how it is represented on the map.

Now open the Protected Areas vector data to show property boundaries.

The problem when we display this first is that we can not see the fire frequency map underneath.

To see what is under this layer we need to change the symbology so that it only shows the outline.

Double click on the fire frequency layer in the layers window to open the properties window.

  1. Select the ‘Symbology‘ view
  2. Select ‘Simple fill
  3. Change the ‘Fill Style‘ to ‘No Brush
  4. Click apply

No we have the only the outline and can see the map underneath.

Now open the late dry season fire frequency map in the folder ‘250m pixel 2010-2019_Last 10 Yrs Fire Frequency after July 31_Image File’. The folder explains that this is only showing fires that occurred after July 31st. These fires tend to be larger and hotter than fires earlier in the year.

We can see that there are fewer fires but we need to worry about where there are the most late dry season fires.

The final map we will view show how long since a particular place burnt. This is usually called a time since last burnt map. You will find this in the ‘250m pixel 2010-2019_Last 10 Yrs Time Since Burnt_Image File’ folder.

The legend for this map shows how many years since a place burnt starting from 2020. So the locations with the value of one, shown as dark brown, burnt in 2019.

This time since last burnt map is usefull for thinking about you burning plan. It shows areas that have not burnt for a long time and might have more grass fuel.