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Trying to utilize the contour extraction QGIS tool but having trouble creating smoothed contours. The smooth, generalize, and dissolve tools have not worked for me. Also the plugin for contours appears to no longer be working? screen shot

  • I eneded up installing SAGA for that. There are many instructions on smoothing relief maps with it. – Ilja Zverev Jun 6 '14 at 16:09
  • Please clarify what kind of problems you have with the existing tools? Do they all freeze like dissolve? – underdark Jun 7 '14 at 7:54
  • The contour tool works in QGIS 2.4.0 – BillW Sep 4 '14 at 5:18
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Sirgeo, don't try to fix up contours after they are generated, the processes take a long time and will eventually lead to intersecting contours = a nightmare!

Instead smooth your raster to take the lumps and bumps out - easier maths and no topology to worry about. I find resample slightly up (cellsize x 1.5) and then back down to the original (or better) cell size works wonders in cleaning up the raster, which will in turn produce smoother and more pleasing contours.

If you can't get the QGIS contours working have a look in the QGIS\bin folder for GDAL_Contour. It works well, so long as you can handle a bit of command line.

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