Regarding the explanation marked below in red, I tried several times to run the following command v.distance but always getting the error message "Not enough column names".
v.distance from=Pxy@Lisboa from_layer=1 to=Proximo@Lisboa to_type=line to_layer=1 upload=to_x,to_y,to_attr to_column=label column=lat output=Res3 dmax=-1 dmin=-1 I also did not get any field to specify the column parameter to "outlet_x,outlet_y". I am running qgis on Linux. Jaime 2012/7/13 Micha Silver <[email protected]> > On 07/13/2012 04:02 PM, Jaime Palalane wrote: > > Dear qgis users, > > I am trying to use qGIS to characterize a hydrographic basin but I am > facing problems with the profile from line tool as it is giving an unique > altitude value for my rivers and lengths in grades. I would like to have > them in SI units. I would appreciate some tips in how to solve this problem. > > > The units should be the units of the coordinate system. I think that if > you want altitudes and lengths in meters, you'll have to project both the > raster and the line features to a projected CRS with meters as units. > > > I am also trying to use the r.water.outlet command to define a basin > draining to a specific point of a stream in raster format but without > success as it gives me back only one cell as the basin and not a > combination of cells which could form a real basin. Any tutorial or video > in how to use this command? > > > Perhaps the problem is that the outlet point must fall exactly on a > stream. There's a trick using v.distance to find a drainage point exactly > on the stream, described here: > > http://www.surfaces.co.il/?p=241 > > First add two columns to the streams layer: outlet_x, outlet_y. Now use > v.distance with your outlet point as the "from" parameter, and the stream > as the "to" parameter. Set the upload parameter to "to_x,to_y" and the > column parameter to "outlet_x,outlet_y". Now after you run, you should get > the X,Y coordinates of a point *on the stream* nearest to your planned > outlet point. Use those coordinates in your r.water.outlet command, and you > should get the full drainage area. > > HTH, > Micha > > > Saudaçoes! > > Jaime > > This mail was received via Mail-SeCure System. > > > _______________________________________________ > Qgis-user mailing > [email protected]http://lists.osgeo.org/mailman/listinfo/qgis-user > > This mail was received via Mail-SeCure System. > > > > > > -- > Micha Silver > GIS Consultant, Arava Development Co.http://www.surfaces.co.il > > -- Jaime Palalane +258 82 70 56 990
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