[GRASS-user] SRTM r.watershed at multiple scales

Markus Neteler neteler at osgeo.org
Sun Aug 18 16:11:30 PDT 2013

On Fri, Aug 16, 2013 at 6:51 PM, jencor808 <jencor808 at gmail.com> wrote:
> Hello all~
> I'm working with SRTM data and trying to produce watershed maps in Honduras.
> For most of the country, the threshold seems to work great at 100000, but
> this is not the case on the shore - those watersheds are neglected likely
> due to their smaller scale. Does anyone have experience merging multiple
> scales? Does this make sense? I'd rather not reduce my threshold or the
> whole country because those watersheds seem too small.
> As an aside, what do people think about using SRTM for watershed mapping in
> the first place - given it is a surface model and not a DEM.

While I cannot help you too much with your first question, you may
take a look at

Metz, M., Mitasova, H., and Harmon, R. S., 2011: Efficient extraction
of drainage networks from massive, radar-based elevation models with
least cost path search, Hydrol. Earth Syst. Sci., 15, 667-678,


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