High-resolution imagery checking your burns.

Using high-resolution mapping through the fire season can be helpful for assessing how your prescribed burning is going.

This mapping is some times provided through an exteral contractor conducting mapping using Sentinel-2 or Landsat imagery. However this mapping can take a while to come through and is not always available.

An easy way to visualize the results of recent burning is using an online site to access recent imagery of you area of interest and display this within QGIS

Here will demonstrate use of the free options available through EO Browser, https://www.sentinel-hub.com/explore/eobrowser.

First you will need to login. This will require registration through the Sign Up. Sign up is free and fast.

Once you have logged

  1. pan in the map window to your area of interest.
  2. Click on the ‘Discover’ tab.
  3. Select Sentinel-2 as the search satellite
  4. Choose the date range you wish to search for satellite imagery.
  5. Click ‘Search’

Choose a cloud free image from your search list and press visualise. Zoom into your specific area of interest

Use the download button to open the download window.

In the download window:

  1. Select ‘Analytical’ as the download format
  2. Select ‘TIFF (16bit) as the image format
  3. Select ‘High’ as the Image resolution. Note the closer your zoom into your area of interest the higher the resolution of the downloaded image.
  4. Select only SWIR as the download visualisation
  5. Press the download button

You can now drag the downloaded tiff into QGIS to view with your other layers.

You can also highlight the burnt areas using a custom combination of bands. Select custom in the visualisation window.

Select ‘Custom Script’.

Copy this script into the custom script window:

function setup() {
  return {
    input: [{
      bands: ["B11", "B12"], // this sets which bands to use
    }],
    output: {
      bands: 1,
      sampleType: "UINT8" // raster format will be UINT8
    }
  };
}
function evaluatePixel(sample) {
  return [(9 * sample.B11 - 10 * sample.B12)*255]; // bands need to be multiplied by 255
}

Click the ‘Refresh’ button below the custom script window. The burnt areas appear much darker than the surrounding country.

Download this using the same method described above but select ‘Custom’ as the Visualised Layer as shown below.

  • Select TIFF (8-bit)
  • Select the image resolution
  • Choose ‘Custom’ as the output visualisation format.

This video shows an example of this process.