[GRASS-user] Topo to Raster

[Mark Seibel]

>
> Hi.
>



> is it possible in GRASS to perform something similar to "Topo to
> Raster" as known in ArcGIS [1]?
>
> [1]
> http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//009z0000007m000000.htm



Are there specific inputs of the "topo to raster" tool that are of
importance for your application?

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.
 The "topo to raster" tool alters the DEM by filling sinks.  The arcgis
approach alters the DEM so that their flow routing tool doesnt stop in
every sink.  My preference is to use the data as close to original source
as possible, and let the superb GRASS flow and routing algorithms handle
routing through the sinks automatically.

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.

HTH,
Mark
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20140304/b91c4fee/attachment.html>