I am trying to correlate contaminant data with other variables. For instance I want to see if high values of contamination coincide with topographic lows in my elevation raster (DEM). All the layers are in raster form, and are covering the same area, and have the same cell size, is there anyway to do this? It would be amazing if the function produces an statistical value indicating if the 2 layers are correlated.

I am using ArcMap 10.3.1 and have access to its other applications (ArcScene, etc)

  • What GIS software are you using?
    – PolyGeo
    Mar 10 '16 at 1:37
  • ArcMap 10.3.1, but I have access to other Arc programs (arcscene, etc) Mar 10 '16 at 1:43
  • 1
    It's not as straightforward as just clicking a button and preso a report. The rasters can be overlaid but determining 'low' areas isn't a mathematical certainty. The difficult part is in establishing your criteria logically or mathematically, I would try to use flow accumulation and a break value established by viewing the data to define 'low' but you will need to establish this yourself based on your data in hand and your definition of low. After you know what is low and not low use Con to create a binary raster which can be intersected with contaminant and then tabulated. Mar 10 '16 at 2:47
  1. Fill your DEM, output - FILLED
  2. Use raster calculator Con (FILLED>DEM, FILLED-DEM), output -DEPTH
  3. Con (DEPTH>=0,INT (1)). Output - DEPRESSIONS.
  4. Convert them to polygons and remove smalls, they are just a noise in your DEM. Output - ZONES. Give them unique names.
  5. Calculate flow direction and flow accumulation -FACC
  6. Use zonal statistics over DEPTH (mean), FACC (maximum), Contaminant (mean or maximum). Avoid using volume of depression and total contamination, this is false correlation.

Do your regression CONTAMINANT (meanDEPTH,maxFACC). Resolution of your contaminant raster might be an issue

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