https://grasswiki.osgeo.org/w/index.php?action=history&feed=atom&title=DEM_to_contour_linesDEM to contour lines - Revision history2026-05-10T15:45:42ZRevision history for this page on the wikiMediaWiki 1.41.0https://grasswiki.osgeo.org/w/index.php?title=DEM_to_contour_lines&diff=20728&oldid=prevNeteler: New2014-09-02T11:28:11Z<p>New</p>
<p><b>New page</b></p><div>== From DEM to vector contour lines ==<br />
<br />
The extraction of isolines (in the case of an elevation surface, contours), can be derived from raster data using the module {{cmd|r.contour}}. Bu default, the module determines the minimum and the maximum isoline values for a given raster map. The isoline/contour interval should be provided by the step parameter.<br />
<br />
Example: generate contours with a 10m interval from the raster map "elevation" (North Carolina [http://grass.osgeo.org/download/sample-data/ sample dataset]):<br />
<br />
<source lang="bash"><br />
# set the computational region<br />
g.region rast=elevation -p<br />
<br />
r.contour elevation out=elev_contour_10m step=10<br />
<br />
# visualize<br />
d.mon x0<br />
d.erase<br />
d.rast elevation<br />
d.vect elev_contour_10m<br />
d.barscale -mt<br />
</source><br />
<br />
The resulting contour lines are now stored in the vector map "elev_contour_10m".<br />
<br />
[[Image:Contour lines from DEM.png|center]]<br />
<br />
== See also ==<br />
* [[Contour lines to DEM]]<br />
<br />
[[Category: FAQ]]<br />
[[Category: Documentation]]<br />
[[Category: Vector]]</div>Neteler