I have a raster file and vector grid of 1000m.

Now i want to find percentage of forest area for each vector grid of 1000m using QGIS.

I have tried Landscape Ecology -> Landscape Vector Overlay plugin but it is giving a memory error.

How can I find this using QGIS with any plugin?

  • 2
    What kind of raster file you have? Already classified into thematic classes (for example forest) or a normal aerial image?
    – Matte
    Mar 30 '16 at 6:07

Probably the easiest approach would be to use the raster calculator to create a binary layer (vegetation/non-vegetation). This could be a thresholded vegetation index.

e.g. "NDVI@1" > 0.2

That way we end up with non-vegetated pixels as 0, and vegetated as 1.

Then you can use zonal statistics to calculate the "sum" (i.e. total vegetated pixels) and "count" (total number of pixels) for the vector grid.

Divide the sum by the total pixel count and it will give you a percentage cover for a vector grid cell.


You can use Zonal Statistics Plugin, I did not try it, but according to the description of the plugin here, it may give you what you are looking for. However, Zonal Statistics function is part of QGIS, so you do not need to download it from Palugin Manager. It is located under Raster > Zonal Statistics.


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