<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1421102856349_9249">W<span style="" class="" id="yui_3_16_0_1_1421102856349_6085">ith regards to the size of DEM, if you can get the command to run it may take several days to finish, this is more than twice the size of the Washington State DEM that took the authors 33 hours in 2003 (Arge, Chase, Halpin, Toma, Urban, Vitter, Wickremesinghe Efficient Flow Computation on Massive Grid Terrain Datasets </span>Geoinformatica
Volume 7 Issue 4, December 2003
<span style="" class="" id="yui_3_16_0_1_1421102856349_6085">Pages 283 - 313
). My mid-2014 computer runs at about twice the speed quoted in the paper.</span></div><div id="yui_3_16_0_1_1421102856349_9112" style="" class="" dir="ltr"><br></div><div id="yui_3_16_0_1_1421102856349_9327" style="" class="" dir="ltr">Did you r.recode it to make it smaller? In flat areas you need the data contained after the decimal point to allow the flow a chance to make it down hill, otherwise you can get streams going no where near where they do in real life. I have never tried running r.terraflow on an integer raster, I know that it works on decimal rasters.<br></div><div id="yui_3_16_0_1_1421102856349_9252" style="" class="" dir="ltr"><br><span style="" class="" id="yui_3_16_0_1_1421102856349_6085"></span></div><div id="yui_3_16_0_1_1421102856349_9207">-Thayer</div><div id="yui_3_16_0_1_1421102856349_9208"><br></div><div id="yui_3_16_0_1_1421102856349_9209"><br></div><div id="yui_3_16_0_1_1421102856349_9285"> <br></div><div id="yui_3_16_0_1_1421102856349_6033" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1421102856349_6032" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1421102856349_6048" class="y_msg_container"> <hr id="yui_3_16_0_1_1421102856349_6079" size="1"><font id="yui_3_16_0_1_1421102856349_6047" face="Arial" size="2"><b><span style="font-weight:bold;"></span></b></font><br>Date: Mon, 12 Jan 2015 09:59:40 -0200<br>From: Daniel Victoria <<a id="yui_3_16_0_1_1421102856349_9328" ymailto="mailto:daniel.victoria@gmail.com" href="mailto:daniel.victoria@gmail.com">daniel.victoria@gmail.com</a>><br>To: grass <<a id="yui_3_16_0_1_1421102856349_9168" ymailto="mailto:grass-user@lists.osgeo.org" href="mailto:grass-user@lists.osgeo.org">grass-user@lists.osgeo.org</a>><br>Subject: [GRASS-user] r.terraflow on massive DEM<br>Message-ID:<br> <CA+irsJjf7xhWgU968D+4+xc2YGJ=<a ymailto="mailto:_n4xJtP0_WeU1ZpoRTt9ng@mail.gmail.com" href="mailto:_n4xJtP0_WeU1ZpoRTt9ng@mail.gmail.com">_n4xJtP0_WeU1ZpoRTt9ng@mail.gmail.com</a>><br>Content-Type: text/plain; charset="utf-8"<br><br>Hi list,<br><br>I'm trying to run r.terraflow on a very large DEM but I wander if it's<br>__too large__.<br><br>The region dimensions are:<br>ncol=141114<br>nrow=140487<br>Data type = CELL<br><br>The map is actually a reclass map of a raster that I imported using<br>r.external.<br><br>When I run r.terraflow I get:<br><br>r.terraflow elevation=<a ymailto="mailto:srtm_brasil@PERMANENT" href="mailto:srtm_brasil@PERMANENT">srtm_brasil@PERMANENT</a> filled=srtm_fill<br>direction=flowdir swatershed=sink accumulation=flowacc tci=srtm_tci<br>directory=E:\terraflow_temp<br><br>WARNING: raster srtm_brasil is of type CELL_TYPE --you should use<br>r.terraflow.short<br>ERROR: [nrows=140487, ncols=141114] dimension_type overflow -- change<br>dimension_type and recompile<br>(Mon Jan 12 09:57:18 2015) Command finished (0<br>sec)<br><br>However, I don't have an r.terraflow.short command<br>I'm running Grass 7.0.0beta4 from OsGeo4W<br><br>Cheers<br>Daniel<br>-------------- next part --------------<br>An HTML attachment was scrubbed...<br>URL: <<a href="http://lists.osgeo.org/pipermail/grass-user/attachments/20150112/a27c139f/attachment-0001.html" target="_blank">http://lists.osgeo.org/pipermail/grass-user/attachments/20150112/a27c139f/attachment-0001.html</a>><br><br>------------------------------<br><br>_______________________________________________<br>grass-user mailing list<br><a ymailto="mailto:grass-user@lists.osgeo.org" href="mailto:grass-user@lists.osgeo.org">grass-user@lists.osgeo.org</a><br><a href="http://lists.osgeo.org/mailman/listinfo/grass-user" target="_blank">http://lists.osgeo.org/mailman/listinfo/grass-user</a><br><br>End of grass-user Digest, Vol 105, Issue 16<br>*******************************************<br><br><br></div> </div> </div> </div></body></html>