I'd like to create several polygon grids with fake species occurrence (see example image)

enter image description here

where each grid cell has a random value between 0 and 5 but high and low values cluster in certain areas as shown in the image.

I've tried the random raster and points tools but they do not cluster sufficiently as they are designed to create random patterns. Any ideas how this can be achieved apart from manually selecting and populating the attribute table of a grid?

  • 1
    Is the raster your end goal, or do you need the actual points? Because creating a raster grid with random values between 0 and 5 seems pretty simple. – csk Aug 28 '19 at 19:45
  • I'm aiming for a raster, the points would just be a workaround. – Kristina Aug 28 '19 at 23:13
  • Perhaps you could generate a point grid, then generate random points (or make a random selection within the point grid), assign the random points values between 1 and 5, buffer those points with random variable buffer distances, and use a spatial join to assign the original value of the random point to all the grid points that intersect the buffer. – csk Aug 29 '19 at 17:09

Just a thought. Snip any picture you like, e.g. night lights. Georeference it to area of interest:

enter image description here


enter image description here

  • That's a good idea, I hadn't thought about using an image. Could you please add some details on how to do the reclassification? I've never done that. Thanks! – Kristina Aug 29 '19 at 14:17
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    Reclassifying a raster is a standard procedure, you can easily find instructions for it now that you know what it's called. Eg, desktop.arcgis.com/en/arcmap/10.3/tools/spatial-analyst-toolbox/… – csk Aug 29 '19 at 16:41
  • Thanks, I was more aiming for a more complete and detailed answer but that link is also helpful. – Kristina Aug 29 '19 at 16:58
  • The easiest way is replaced stretched symbology by on of classified, e.g. equal interval and launch reclassify tool. It will honor intervals from symbology. Before that convert multiband image to single band using make raster layer tool. – FelixIP Aug 29 '19 at 19:32

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