<div dir="ltr">Thanks Daniel, <div><br><div>Since I am developing Grass Gis based interactive app to delineate watershed basin, I have to bundle those raster files along with other python packages. When the users installs the app, these files will be automatically copied and ready to use for "r.water.outlet" module through python script i.e. users just have to enter coordinate in the GUI.There will be just a single pair of coordinate at a time. </div></div><div><br></div><div>My concern is that whether drainage direction raster map can be used for r.distance or not? Do we achieve the same result?</div><div><br></div><div>Bundling the accumulation raster file massively increases the app setup file size whereas drainage direction only accounts 1/4th size of accumulation raster file. </div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div style="font-size:12.8px"><b>Best,</b></div><div style="font-size:12.8px"><b>Ang</b></div></div></div></div>
<br><div class="gmail_quote">On Wed, Mar 29, 2017 at 9:49 PM, Daniel Victoria <span dir="ltr"><<a href="mailto:daniel.victoria@gmail.com" target="_blank">daniel.victoria@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg">Hi Ang,<br><br></div><div class="m_-8067708184178616528gmail_msg">I had replied off list. I'm now replying to the list so other can comment<br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg"></div>The idea is that to delineate watersheds, the outlet has to lie in a
place with high accumulation. So if you get your outlet points a bit
messed up, a way to force them to go to the right place is to use
r.distance.<br class="m_-8067708184178616528gmail_msg"></div><br class="m_-8067708184178616528gmail_msg"></div>I don't
have a specific code nor I recall the steps I've taken back in 2010, when I did this. But, looking at
the r.distance manual [1], this is what I'd try if I had to repeat the
process today:<br class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg"></div>1) Convert my outlet points to raster, each with a different category<br class="m_-8067708184178616528gmail_msg"></div>2) Threshold your flow accumulation map in order to delineate the rivers (high flow accumulation)<br class="m_-8067708184178616528gmail_msg">3)
Run r.distance to find the closest river line to each of your output
point. Check that you don't create any points to far away from the
original position.<br class="m_-8067708184178616528gmail_msg"></div>4) Use the output of r.distance as the coordinates in r.water.outlet<br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg">Cheers<br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg">Daniel<br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg">[1] - <a href="https://grass.osgeo.org/grass72/manuals/r.distance.html" class="m_-8067708184178616528gmail_msg" target="_blank">https://grass.osgeo.org/<wbr>grass72/manuals/r.distance.<wbr>html</a></div></div></div></div>
</div><br><div class="gmail_quote"><div><div class="h5"><div dir="ltr">On Wed, Mar 29, 2017 at 12:55 PM Ang Sherpa <<a href="mailto:angsherpa232@gmail.com" target="_blank">angsherpa232@gmail.com</a>> wrote:<br></div></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><div dir="ltr" class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg">Hi users,</div><div class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg">While using "r.water.outlet" to delineate watershed basin, although the coordinates of the stream was noted from google earth and fed into "r.water.outlet" module, it produces plain raster. </div><div class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg">Is there any solution to make sure that the coordinates of outlet point automatically snaps to the nearest line of stream in drainage direction map?</div><div class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg"></div><div class="m_-8067708184178616528gmail_msg">Any words will be appreciated.</div><div class="m_-8067708184178616528gmail_msg"><br class="m_-8067708184178616528gmail_msg"></div><br clear="all" class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528gmail_msg"><div class="m_-8067708184178616528m_-4848570150643095785gmail_signature m_-8067708184178616528gmail_msg" data-smartmail="gmail_signature"><div dir="ltr" class="m_-8067708184178616528gmail_msg"><div style="font-size:12.8px" class="m_-8067708184178616528gmail_msg"><b class="m_-8067708184178616528gmail_msg">Best,</b></div><div style="font-size:12.8px" class="m_-8067708184178616528gmail_msg"><b class="m_-8067708184178616528gmail_msg">Ang</b></div></div></div></div>
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