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r.slopeunits.create

Create a raster layer of slope units

r.slopeunits.create [-gs] demmap=name [plainsmap=name] slumap=name [slumapvect=name] [circvarmap=name] [areamap=name] thresh=float areamin=float [areamax=float] cvmin=float rf=integer maxiteration=integer [generalize_treshold=float] [convergence=integer] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

r.slopeunits.create demmap=name slumap=name thresh=0.0 areamin=0.0 cvmin=0.0 rf=0 maxiteration=0

grass.script.run_command("r.slopeunits.create", demmap, plainsmap=None, slumap, slumapvect=None, circvarmap=None, areamap=None, thresh, areamin, areamax=None, cvmin, rf, maxiteration, generalize_treshold=20, convergence=5, flags=None, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

gs.run_command("r.slopeunits.create", demmap="name", slumap="name", thresh=0.0, areamin=0.0, cvmin=0.0, rf=0, maxiteration=0)

grass.tools.Tools.r_slopeunits_create(demmap, plainsmap=None, slumap, slumapvect=None, circvarmap=None, areamap=None, thresh, areamin, areamax=None, cvmin, rf, maxiteration, generalize_treshold=20, convergence=5, flags=None, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

tools = Tools()
tools.r_slopeunits_create(demmap="name", slumap="name", thresh=0.0, areamin=0.0, cvmin=0.0, rf=0, maxiteration=0)

This grass.tools API is experimental in version 8.5 and expected to be stable in version 8.6.

Parameters

demmap=name [required]
    Input digital elevation model
plainsmap=name
    Input raster map of alluvial plains
slumap=name [required]
    Output Slope Units layer (the main output)
slumapvect=name
    Output Slope Units layer as vector layer
circvarmap=name
    Output Circular Variance layer
areamap=name
    Output Area layer; values in square meters
thresh=float [required]
    Initial threshold (m^2).
areamin=float [required]
    Minimum area (m^2) below which the slope unit is not further segmented
areamax=float
    Maximum area (m^2) above which the slope unit is segmented irrespective of aspect
cvmin=float [required]
    Minimum value of the circular variance (0.0-1.0) below which the slope unit is not further segmented
rf=integer [required]
    Factor used to iterativelly reduce initial threshold: newthresh=thresh-thresh/reductionfactor
maxiteration=integer [required]
    maximum number of iteration to do before the procedure is in any case stopped
generalize_treshold=float
    Threshold for maximal tolerance value for v.generalize
    Allowed values: 0-1000000000
    Default: 20
convergence=integer
    Convergence factor for MFD in r.watershed (1-10)
    1 = most diverging flow, 10 = most converging flow. Recommended: 5
    Default: 5
-g
    Generalize Slope Units vector layer
-s
    SFD (D8) flow in r.watershed (default is MFD)
    SFD: single flow direction, MFD: multiple flow direction
--overwrite
    Allow output files to overwrite existing files
--help
    Print usage summary
--verbose
    Verbose module output
--quiet
    Quiet module output
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

demmap : str, required
    Input digital elevation model
    Used as: input, raster, name
plainsmap : str, optional
    Input raster map of alluvial plains
    Used as: input, raster, name
slumap : str, required
    Output Slope Units layer (the main output)
    Used as: output, raster, name
slumapvect : str, optional
    Output Slope Units layer as vector layer
    Used as: output, vector, name
circvarmap : str, optional
    Output Circular Variance layer
    Used as: output, raster, name
areamap : str, optional
    Output Area layer; values in square meters
    Used as: output, raster, name
thresh : float, required
    Initial threshold (m^2).
areamin : float, required
    Minimum area (m^2) below which the slope unit is not further segmented
areamax : float, optional
    Maximum area (m^2) above which the slope unit is segmented irrespective of aspect
cvmin : float, required
    Minimum value of the circular variance (0.0-1.0) below which the slope unit is not further segmented
rf : int, required
    Factor used to iterativelly reduce initial threshold: newthresh=thresh-thresh/reductionfactor
maxiteration : int, required
    maximum number of iteration to do before the procedure is in any case stopped
generalize_treshold : float, optional
    Threshold for maximal tolerance value for v.generalize
    Allowed values: 0-1000000000
    Default: 20
convergence : int, optional
    Convergence factor for MFD in r.watershed (1-10)
    1 = most diverging flow, 10 = most converging flow. Recommended: 5
    Default: 5
flags : str, optional
    Allowed values: g, s
    g
        Generalize Slope Units vector layer
    s
        SFD (D8) flow in r.watershed (default is MFD)
        SFD: single flow direction, MFD: multiple flow direction
overwrite : bool, optional
    Allow output files to overwrite existing files
    Default: None
verbose : bool, optional
    Verbose module output
    Default: None
quiet : bool, optional
    Quiet module output
    Default: None
superquiet : bool, optional
    Very quiet module output
    Default: None

demmap : str | np.ndarray, required
    Input digital elevation model
    Used as: input, raster, name
plainsmap : str | np.ndarray, optional
    Input raster map of alluvial plains
    Used as: input, raster, name
slumap : str | type(np.ndarray) | type(np.array) | type(gs.array.array), required
    Output Slope Units layer (the main output)
    Used as: output, raster, name
slumapvect : str, optional
    Output Slope Units layer as vector layer
    Used as: output, vector, name
circvarmap : str | type(np.ndarray) | type(np.array) | type(gs.array.array), optional
    Output Circular Variance layer
    Used as: output, raster, name
areamap : str | type(np.ndarray) | type(np.array) | type(gs.array.array), optional
    Output Area layer; values in square meters
    Used as: output, raster, name
thresh : float, required
    Initial threshold (m^2).
areamin : float, required
    Minimum area (m^2) below which the slope unit is not further segmented
areamax : float, optional
    Maximum area (m^2) above which the slope unit is segmented irrespective of aspect
cvmin : float, required
    Minimum value of the circular variance (0.0-1.0) below which the slope unit is not further segmented
rf : int, required
    Factor used to iterativelly reduce initial threshold: newthresh=thresh-thresh/reductionfactor
maxiteration : int, required
    maximum number of iteration to do before the procedure is in any case stopped
generalize_treshold : float, optional
    Threshold for maximal tolerance value for v.generalize
    Allowed values: 0-1000000000
    Default: 20
convergence : int, optional
    Convergence factor for MFD in r.watershed (1-10)
    1 = most diverging flow, 10 = most converging flow. Recommended: 5
    Default: 5
flags : str, optional
    Allowed values: g, s
    g
        Generalize Slope Units vector layer
    s
        SFD (D8) flow in r.watershed (default is MFD)
        SFD: single flow direction, MFD: multiple flow direction
overwrite : bool, optional
    Allow output files to overwrite existing files
    Default: None
verbose : bool, optional
    Verbose module output
    Default: None
quiet : bool, optional
    Quiet module output
    Default: None
superquiet : bool, optional
    Very quiet module output
    Default: None

Returns:

result : grass.tools.support.ToolResult | np.ndarray | tuple[np.ndarray] | None
If the tool produces text as standard output, a ToolResult object will be returned. Otherwise, None will be returned. If an array type (e.g., np.ndarray) is used for one of the raster outputs, the result will be an array and will have the shape corresponding to the computational region. If an array type is used for more than one raster output, the result will be a tuple of arrays.

DESCRIPTION

r.slopeunits.create creates a raster layer of slope units. Optionally, a vector map can be created.

EXAMPLE

r.slopeunits.create \
    demmap=dem_italia_isolegrandi@su_test \
    plainsmap=flat \
    slumap=su_tmp \
    thresh=250000 \
    areamin=200000 \
    cvmin=0.25 \
    rf=2 \
    maxiteration=50

REFERENCES

  • Alvioli, M., Marchesini, I., Reichenbach, P., Rossi, M., Ardizzone, F., Fiorucci, F., and Guzzetti, F. (2016): Automatic delineation of geomorphological slope units with r.slopeunits v1.0 and their optimization for landslide susceptibility modeling, Geosci. Model Dev., 9, 3975-3991. DOI:10.5194/gmd-9-3975-2016
  • Alvioli, M., Guzzetti, F., & Marchesini, I. (2020): Parameter-free delineation of slope units and terrain subdivision of Italy. Geomorphology, 358, 107124. DOI:10.1016/j.geomorph.2020.107124

SEE ALSO

r.slopeunits.clean, r.slopeunits.metrics, r.slopeunits.optimize

AUTHORS

Main authors: Ivan Marchesini, Massimiliano Alvioli, CNR-IRPI
Markus Metz (refactoring), mundialis

SOURCE CODE

Available at: r.slopeunits.create source code (history)
Latest change: Wednesday May 07 16:16:50 2025 in commit 8af96b6