Rich,<br><br><div class="gmail_quote">On Sat, Apr 7, 2012 at 3:51 PM, Rich Shepard <span dir="ltr"><<a href="mailto:rshepard@appl-ecosys.com">rshepard@appl-ecosys.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="im">On Sat, 7 Apr 2012, Margherita Di Leo wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
r.basin produces several maps for every run, which are flow direction,<br>
accumulation, Horton ordered streams etc.. Prefix parameter is simply a<br>
string given by the user in order to distinguish all the maps produced by a<br>
single run of the program, i.e. every set of coords for outlet. For<br>
example,<br>
</blockquote>
<br></div>
madi,<br>
<br>
I thought this is the case, but wanted to know rather than assume.<div class="im"><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Threshold parameter is the same of r.watershed. 'Autothreshold ' flag'<br>
simply uses a threshold area of 1 km^2 and is intended as a tentative.<br>
</blockquote>
<br></div>
Again, rather than assuming I wanted to be sure I understood.<div class="im"><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
For what concerns r.stream.basin, it is a typo in the documentation,<br>
correct is r.stream.basins, thanks for pointing me out, I just updated it<br>
in the description file.<br>
<a href="http://r.wf.py" target="_blank">r.wf.py</a> and <a href="http://r.ipso.py" target="_blank">r.ipso.py</a> are in the addOns repository:<br>
</blockquote>
<br></div>
Ah, I see why they did not download for me: I added the .py extention to<br>
the g.estension command. Now I know to leave it off.<div class="im"><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Please note that r.basin is intended to work with only one outlet at time.<br>
This means you should script it in a for cycle if you run it for several<br>
outlets.<br>
</blockquote>
<br></div>
I understand this.<div class="im"><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
You can't give to r.basin the coordinates directly from a vector map.<br>
</blockquote>
<br></div>
But, can I use the coordinates of a rasterized stream network?</blockquote><div><br></div><div>No. Do you think this would be an useful add? If so, I could work on it when I have some spare time.. Let me know.</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="im"><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I have indicated to run r.stream.extract before r.basin because most of the<br>
times the calculated stream network doesn't match with the natural one, so<br>
that your coordinates should be adjusted to match the calculated stream<br>
network in order to get a result from r.basin. By the way, in a first run<br>
you can give a try with your coordinates.<br>
</blockquote>
<br></div>
The outputs of r.stream.extract on two different project sub-watersheds<br>
are, as far as I can see on the display, only about 5-10% of the vector<br>
stream network, and all at the lower ends of the basins in which they<br>
appear. I can send screen shots if you'd like to see the differences.<br></blockquote><div><br></div><div>AFAICT this could be due to an odd value for the threshold, or a g.region or mask related problem. Please try setting g.region to match the elevation map, removing the mask and setting a lower threshold value.</div>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
After downloading and building the 'missing' three modules I'll try<br>
v.to.rast on the natural stream network (at 1:24,000 scale, just like the<br>
elevation data) and see what r.basin tells me.<br></blockquote><div><br></div><div>Let me know about your results.</div><div><br></div><div>madi </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
Many thanks,<div class="HOEnZb"><div class="h5"><br>
<br>
Rich<br>
<br>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br>Ing. Margherita Di Leo, Ph.D.<br>