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I am trying to complete an analysis that assesses the likelihood of fire.

From literature I have found that fire is most likely in south facing slopes and least likely in North facing.

Datasets I was planning on using are fire events and aspect. I have currently performed aspect analysis (spatial analyst) on DEM and reclassified the values so each of the 9 directions (N, NE, E, SE, S, SW, W, NW, Flat) have a unique value.

I thought I would then be able to convert raster to polygon then select by location the fire events in each direction - however that does not work.

Are there any suggestions of how i could analyse the number of fire events in each aspect.

(Fire events are points, and aspect raster)

Image of aspect raster file

enter image description here

Error Message for extract multivalues to point enter image description here

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The best tool in your case would be "extract multivalues to point", which will add a new field with the values of your raster for each point. You can then get an histogram of the aspect. Don't use the mean value, however, because aspect goes from 0 to 360°, therefore the mean value near the North is 180°(which is completely at the opposite site.

  • do your layer have the same coordinate system and overlap correctly ? – radouxju Dec 21 '16 at 13:23
  • yes I believe they do, they are in the same coordinate system atleast, how do i check if they overlap correctly? – Elizabeth Dec 21 '16 at 13:23
  • are they displayed on top of each other in ArcMap ? – radouxju Dec 21 '16 at 13:25
  • Yes, layer on top of each other – Elizabeth Dec 21 '16 at 13:26
  • could you edit your post with error message, please. This is not normal. – radouxju Dec 21 '16 at 13:32

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