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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

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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.

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  • do your layer have the same coordinate system and overlap correctly ?
    – radouxju
    Dec 21, 2016 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, 2016 at 13:23
  • are they displayed on top of each other in ArcMap ?
    – radouxju
    Dec 21, 2016 at 13:25
  • Yes, layer on top of each other
    – Elizabeth
    Dec 21, 2016 at 13:26
  • could you edit your post with error message, please. This is not normal.
    – radouxju
    Dec 21, 2016 at 13:32

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