Markus Metz wrote:<br><pre>In my personal opinion, flow accumulation of r.watershed is also more<br>realistic than flow accumulation of r.terraflow (SFD), but I have<br>admittedly not tested it in detail.<br></pre><br>I just wanted to add that I have, in fact, compared the results of the r.watershed with r.terraflow, as well as with r.flow. In my opinion, r.watershed consistently gives more accurate results than either of the other two. r.flow gives the worst results (for the kind of process modeling that I am interested in at least), while r.terraflow provides somewhat better results. Both modules produce results with "spikes" of high values that do not correspond perfectly with real topographic changes (or perhaps it is better to say that they overestimate changes in accumulation at certain places on the landscape), but r.watershed does not do that. The only reason I was not using the old r.watershed in my scripts was the time vs. map size issue. It was impossible to build it in as a dependant if it would make the modle hang for days if the input map was too big for it. However, I am please to say that initial tests running my r.landscape.evol with new r.watershed are VERY encouraging! Not only does the whole thing run faster, the results are MUCH more realistic! I may even be able to remove a time consuming "smoothing" routine from the module since it seems that I no longer am creating the anomolous "spikes" in elevation change do to problems in the flowacc map. This, I think, is a very good reason for focusing more development "sweat" to perfecting r.watershed. For future reference, I am more than happy to test out any changes to the module....<br>
<br>Cheers<br clear="all"><br>-- <br><br>Isaac I Ullah, M.A.<br><br>Archaeology PhD Student,<br>ASU School of Evolution and Social Change<br><br>Research Assistant,<br>Mediterranean Landscape Dynamics Project<br>***************************************************<br>
<a href="mailto:isaac.ullah@asu.edu">isaac.ullah@asu.edu</a><br><a href="mailto:ullah@archaeologist.com">ullah@archaeologist.com</a><br><br><a href="http://www.public.asu.edu/~iullah">http://www.public.asu.edu/~iullah</a><br>
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