[Qgis-user] raster: calculate area

[chris hermansen]

Azzurra and list;

On Thu, Jan 28, 2021 at 2:31 PM Azzurra Lentini <azzurralentini at gmail.com>
wrote:

> Hi List,
> I have a raster file DTM (altitude attribute in the pixels). I
> reclassified this raster in 4 classes of altitude and I need to calculate
> for each class  the area (in how many square meters is each different class
> extended).
> I can for example transform the raster file reclassified into a vector
> file and calculate the area, but is it possible to do without any
> vectorialization and so directly calculating it from the raster file?
>

You might wish to review the following link

https://gis.stackexchange.com/questions/52353/calculating-area-of-rasters-in-qgis

It suggests two approaches - using raster statistics to get the count by
classes and multiplying by the pixel area, or vectorizing, and points out
that in vectorizing you get "cluster areas", not just the total count of
pixels of each class.


-- 
Chris Hermansen · clhermansen "at" gmail "dot" com

C'est ma façon de parler.
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