NAME

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

SYNOPSIS

          gdal_contour [-b <band>] [-a <attribute_name>] [-amin <attribute_name>] [-amax <attribute_name>]
                       [-3d] [-inodata]
                       [-snodata n] [-i <interval>]
                       [-f <formatname>] [[-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.

       -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

       1998-2022

                                           Jun 30, 2022                           GDAL_CONTOUR(1)