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I am attempting to workout landcover change between two classified landcover maps. Ideally I want to show percentage change between the years per landcover type. I think I have done this but I am unsure whether my calculations are correct as the percentages seem to be very high...

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Also, my main interest in the study is seeing how palm oil (large concessions and smallholders), has caused habitat loss (in this case loss of forest) from 1973 - 2014. Is there an elegant way of showing this in both map form and also graph/table form? This is the current landcover map I have made.

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I haven't been able to work out a solution as of yet.

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I see a bunch of polygon boundaries in there. Since this information started out as a classified raster you probably will have better luck doing the tabulations in raster.

First mask your classified raster data to the study area with the Clip Raster tool (Clip_management in ArcMap), then try the Tabulate Areas tool to get a table of totals by study area (in raster).

Using raster format, it is also much easier to do things like create Boolean (true/false, 1/0) rasters to create maps of change one way or the other using the Raster Calculator. MUCH easier then trying to do this as polygon features.

Hope this helps.

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  • Hello Curtis, thank you for your reply. I am not very familiar with how the raster calculator works. If I was to see area change from rainforest to oil palm what sort of function would I type? Kind regards, Connor.
    – Connor R
    Commented Apr 11, 2020 at 9:25
  • A usual way to handle this with raster calculator is to use an expression to create a boolean raster, for example, assuming rainforest = 1 and palm = 2: ("g1973" == 1) & ("g2014" == 2) would create cells "1" where this was true and "0" where cells are false. Set the mask to your study area before running the raster calculator and the the raster table would have a count of how many pixels in each group within your study area.
    – Curtis Price
    Commented Apr 12, 2020 at 6:12
  • Okay thank you for your time! I'll give it a try.
    – Connor R
    Commented Apr 12, 2020 at 12:44

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