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I am trying to extract information on the % of different vegetation cover types within areas that have not been burned. However, the data I was given for the park includes areas that have been burned as a raster file in NAD_83 projection, and the vegetation cover as a polygon layer in WGS_84 projection. Essentially, I'm trying to erase the overlap between areas that have been burned and the vegetation layer to only look at vegetation cover types in areas that have not been burned. The vegetation is broken into 12 class labels based on understory/shrub cover type, and I want a percentage of how much each cover type occurs in unburned area. Can anyone help with this transformation?

I have access to ArcGIS Desktop v 10.8.2 with an Advanced licence.

I have tried converting the raster to points which worked, but I don't know how to make the points into polygons that perfectly match the size/shape of the original raster. I don't know another way to "erase" the two layers other than by trying to convert the raster to a polygon with the same coordinate system.

Ken White
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Zoe
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  • This question does not seem to be about programming or software development. That makes it inappropriate for this site. You could try on gis.stackexchange.com instead – Robert Hijmans Nov 15 '22 at 03:47

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ArcMap is probably reprojecting the data on the fly, but you could start by transforming the raster and vector layers to a common datum.

If I understand correct, you want to know the area of veg types represented as polygons that are within unburned areas which are represented as pixels in a raster.

If that is correct, I would convert the unburned areas to a polygon layer. It might help to convert the burn raster such that unburned = 1 all else = 0 or NA, then convert unburned to a polygon.

With the unburned areas represented as polygons, intersect this layer with the veg layer. Doing so will cut the veg layer by the unburn polygon layer. The result should allow you to only select polygons that intersected with the unburned layer once it is vectorized. Get the area of these polygons grouped by veg type.

ncraig
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