GDAL_CONTOUR(1)                      GDAL                      GDAL_CONTOUR(1)

NAME
       gdal_contour - Builds vector contour lines from a raster elevation
       model.

SYNOPSIS

          gdal_contour [--help] [--help-general]
                       [-b <band>] [-a <attribute_name>] [-amin <attribute_name>] [-amax <attribute_name>]
                       [-3d] [-inodata] [-snodata <n>] [-f <formatname>] [-i <interval>]
                       [-dsco <NAME>=<VALUE>]... [-lco <NAME>=<VALUE>]...
                       [-off <offset>] [-fl <level> <level>...] [-e <exp_base>]
                       [-nln <outlayername>] [-q] [-p]
                       <src_filename> <dst_filename>

DESCRIPTION
       The gdal_contour generates a vector contour file from the input raster
       elevation model (DEM).

       The contour line-strings are oriented consistently and the high side
       will be on the right, i.e. a line string goes clockwise around a top.

       --help Show this help message and exit

       --help-general
              Gives a brief usage message for the generic GDAL commandline
              options and exit.

       -b <band>
              Picks a particular band to get the DEM from. Defaults to band 1.

       -a <name>
              Provides a name for the attribute in which to put the elevation.
              If not provided no elevation attribute is attached.  Ignored in
              polygonal contouring (-p) mode.

       -amin <name>
              Provides a name for the attribute in which to put the minimum
              elevation of contour polygon. If not provided no minimum
              elevation attribute is attached. Ignored in default line
              contouring mode.

              New in version 2.4.0.


       -amax <name>
              Provides a name for the attribute in which to put the maximum
              elevation of contour polygon. If not provided no maximum
              elevation attribute is attached.  Ignored in default line
              contouring mode.

              New in version 2.4.0.


       -3d    Force production of 3D vectors instead of 2D.  Includes
              elevation at every vertex.

       -inodata
              Ignore any nodata value implied in the dataset - treat all
              values as valid.

       -snodata <value>
              Input pixel value to treat as "nodata".

       -f <format>
              Create output in a particular format.

              New in version 2.3.0: If not specified, the format is guessed
              from the extension (previously was ESRI Shapefile).


       -dsco <NAME>=<VALUE>
              Dataset creation option (format specific)

       -lco <NAME>=<VALUE>
              Layer creation option (format specific)

       -i <interval>
              Elevation interval between contours.

       -off <offset>
              Offset from zero relative to which to interpret intervals.

       -fl <level>
              Name one or more "fixed levels" to extract.

       -e <base>
              Generate levels on an exponential scale: base ^ k, for k an
              integer.

              New in version 2.4.0.


       -nln <name>
              Provide a name for the output vector layer. Defaults to
              "contour".

       -p     Generate contour polygons rather than contour lines.

              New in version 2.4.0.


       -q     Be quiet.

C API
       Functionality of this utility can be done from C with
       GDALContourGenerate().

EXAMPLE
       This would create 10-meter contours from the DEM data in dem.tif and
       produce a shapefile in contour.shp|shx|dbf with the contour elevations
       in the elev attribute.

          gdal_contour -a elev dem.tif contour.shp -i 10.0

AUTHOR
       Frank Warmerdam <warmerdam@pobox.com>, Silke Reimer
       <silke@intevation.de>

COPYRIGHT
       1998-2024

                                 April 2, 2024                 GDAL_CONTOUR(1)