[Qgis-user] Bathymetry data area coverage calculator

[Peters]

Very helpful. Yes, our data is raster. I saw a calculator tool in the
raster toolbar but haven't been able to figure it out or if it's pertinent.

On Sat, Jul 31, 2021, 19:01 Charles Dixon-Paver <charles at kartoza.com> wrote:

> I think you will need to provide more information on describing the input
> data, as well as how exactly you wish to process it.
>
> If your coverage data is vector areas you should be able to simply use the
> aggregate processing tool using $area as the source expression and
> stipulate a sum aggregate function. You may also use the grouping
> function to filter the results as needed using an expression.
>
> This would provide the area based on map units, so you would need to
> reproject your data into a relevant metric projection before performing the
> aggregation. A single hectare is simply 10000 m² so simple arithmetic will
> allow you to convert metric areas to hectares.
>
> If your data is another vector data type such as point clouds, you may
> need to buffer or calculate a minimum bounding geometry or convex hull
> before processing it as the area calculation will of course only work on
> area features.
>
> For raster data, the total area would be a simple calculation of the
> extents, or the dimensions and cell size. Again, you may need to reproject
> the data for it to be available in meters.
>
> If, however, you wish to segregate raster data based on cell value, you
> may want to recode and vectorize the data, or alternatively perform some
> form of custom analysis as described in the following article:
> https://www.kartoza.com/en/blog/calculating-area-of-rasters-in-qgis/
>
> Regards
>
> On Sat, 31 Jul 2021 at 19:15, Peters <petersinmorocco at gmail.com> wrote:
>
>> Does anyone know of such a calculator as a plugin or option?  At the
>> moment I am using QGIS app. Our client has asked for area coverage in sq.
>> mtrs or hectares. Appreciate any info you may have.
>>
>> --
>> *regards,*
>> *K. Peters*
>>
>> *cell: (Morocco) +212.671.218606*
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