Classifying dNBR images

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09-13-2017 07:38 AM
PaulRobinson6
New Contributor

I have a string of around 70 dNBR images designed to assess burn scarring as part of the June 2017 Knysna Forest fires. However, the images do not look correct, particularly when comparing them to unprocessed post-fire images containing only visible bands. I I have been asked to change the classification by eye, manually altering the breaks and to reclassifying the dNBR images into 4 features ranging from unburned to high-burn severity. Using various classification models found in articles has not been effective, even when changing the total number of features. I am now using ArcMap and not ArcGIS Pro and manually moving the natural break bars under classification in layer features for each image. The issue is I don't really know how a more appropriate dNBR image is supposed to look and therefore progress is slow. Any advice on where to start would be greatly apprenticed.

Working with Sentinel-2 and Landsat-8 images over months Jan-Sept 2017.

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2 Replies
MichelleMathias
Community Manager

Hi Paul,

 

Thanks for asking your questions and welcome to the GeoNet community! I wanted to let you know that we're moving your question to the ArcGIS Desktop Installation Support space and also share it into the ArcGIS Pro group so our Esri and user subject matter experts can further help answer this and future questions.  So you're aware on how and where to post your questions, here's a few quick tips and reminders:

  • First, use the GeoNet search (top right corner by your profile icon) to search and see if your question has already by asked/answered previously.

 

Thanks again for contributing and I hope this helps and let us know if you have any questions.

Community Manager, Esri Community Team.
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V_StuartFoote
MVP Frequent Contributor

Not my cup of tea, but a few moments with Google reveals several dNBR methods papers with basics of dNBR classification.

https://www.fs.fed.us/postfirevegcondition/documents/MillerThodeRse2007.pdf 

https://burnseverity.cr.usgs.gov/pdfs/LAv4_BR_CheatSheet.pdf 

And alternate RBR analysis approach.

http://www.mdpi.com/2072-4292/6/3/1827/pdf 

You can probably dig deeper into the journal published literature from any technical library.