Hi Soeren and all, I appreciate the opinion, and in fact have split continents in the past, but the project that I want to undertake requires many calculations with variable sea-levels and would be much easier to run on a full globe (albeit with null values in the ocean at each particular time-step).
That, and this unfortunately still doesn't address doing Antarctica without reprojecting. So really what I am saying is that I would like to hear ideas about the technical side of r.watershed (maybe I should just email Markus Metz directly) and how to change where it creates sinks. I know that it is able to go across the 180 meridian, so this boundary has been modified for lat/lon, and it therefore in my mind would be feasible to tell it that the north and south poles are not a sink for flow. If there is really no way to do this with r.watershed, I will write code myself, but I am hoping that I can instead just improve r.watershed. Thanks, Andy On Fri, Oct 2, 2015 at 2:04 AM, Sören Gebbert <[email protected]> wrote: > Hi Andy, > running r.watershed for the whole globe is IMHO not necessary. Just > run r.watershed for each continent (except Europe/Asia) and isles > (greenland, UK, ...). Everything that is parted by an ocean or a > channel can be processed independently. > > Best regards > Soeren > > 2015-10-02 0:27 GMT+02:00 Andy Wickert <[email protected]>: > > On Thu, Oct 1, 2015 at 3:52 PM, Markus Neteler <[email protected]> > wrote: > >> > >> On Thu, Oct 1, 2015 at 7:10 AM, Andy Wickert <[email protected]> > >> wrote: > >> > Dear GRASS developers, > >> > > >> > Would you know of an easy way to make r.watershed work in > >> > latitude/longitude > >> > over the pole of a planet (in my case, over Antarctica) by specifying > >> > that > >> > the polar boundary in lat/lon is not a sink? > >> > >> Wouldn't be a stereographic projection more appropriate? > >> > >> > >> > https://grass.osgeo.org/uploads/images/Gallery/raster/polar_stereographic.png > >> > >> Best > >> Markus > > > > > > Thanks for the suggestion. However, my goal is to run r.watershed across > the > > whole globe, so a stereographic projection would an ad-hoc solution. > > > > (I have also had problems in the past projecting between polar > stereographic > > and lat/lon, but this is a secondary issue.) > > > > Andy > > > > _______________________________________________ > > grass-dev mailing list > > [email protected] > > http://lists.osgeo.org/mailman/listinfo/grass-dev >
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