[GRASS-user] Topo to Raster
landa.martin at gmail.com
Tue Apr 1 03:37:21 PDT 2014
2014-03-04 19:25 GMT+01:00 Mark Seibel <mseibel at gmail.com>:
> Are there specific inputs of the "topo to raster" tool that are of
> importance for your application?
not really I just want to show my students that almost everything what
they are doing in the class using ArcGIS they can do using open source
GRASS GIS quite easily :-)
> Using contour lines as input, I have found the r.surf.nnbathy module to
> perform very well. For (LiDAR) point data, my preference is v.surf.rst.
Right, `r.surf.nnbathy` is based on Pavel Sakov's nn natural neighbor
interpolation library. This library is provided in MIT licence. Then
we could probably incorporate it into main GRASS source code, right? I
found code in Addons , btw, link at  doesn't work. The module is
written as a bash script and needs to be ported to Python for G7.
What do you think?
> If one wanted to mimic the arcgis method of filling sinks after
> interpolating, one could run iterations of r.fill.dir to make it
> depression-less. This isnt necessary with the hydrologic tools in GRASS
> because the r.watershed algorithm is intelligent enough to keep seeking the
> next lowest location the DEM. Add in the fact that r.watershed has MFD, and
> GRASS quickly surpasses the ESRI hydrologic toolset offerings.
Thanks for clarification.
Martin Landa * http://geo.fsv.cvut.cz/gwiki/Landa
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