[gdal-dev] Gdal_grid and lake bathymetry

[Even Rouault]

On mardi 19 novembre 2019 22:03:29 CET Rahkonen Jukka (MML) wrote:
> Hi,
> 
> I would like to get some hints about using gdal_grid or some other utility
> for lake bathymetry. What I have is typically rather sparse point data of
> depths and the shoreline that includes the islands as in the attached
> image. The shoreline and all the area that is not lake basin should have
> the altitude of zero in the resulting DEM. It means that interpolation
> should not overshoot across the shoreline over the dry land.
> 
> Gdal_grid seems to miss an option for handling the shoreline so I made a
> test by converting the vertices of the polygon rings into depth points. I
> also filled area around the lake with a gridded points of zero altitude but
> the method feels stupid and tedious and the result was not so fine when it
> comes to keep the shoreline and land area near it totally flat.
> 

Postprocessing with gdalwarp -cutline to set to zero non-lake areas ?

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