Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
r.param.scale(1)	    GRASS GIS User's Manual	      r.param.scale(1)

NAME
       r.param.scale  -	Extracts terrain parameters from a DEM.
       Uses  a	multi-scale approach by	taking fitting quadratic parameters to
       any size	window (via least squares).

KEYWORDS
       raster, geomorphology, terrain, elevation, landform

SYNOPSIS
       r.param.scale
       r.param.scale --help
       r.param.scale  [-c]  input=name	output=name    [slope_tolerance=float]
       [curvature_tolerance=float]   [size=integer]   [method=string]	[expo-
       nent=float]    [zscale=float]	[--overwrite]	[--help]   [--verbose]
       [--quiet]  [--ui]

   Flags:
       -c
	   Constrain model through central window cell

       --overwrite
	   Allow output	files to overwrite existing files

       --help
	   Print usage summary

       --verbose
	   Verbose module output

       --quiet
	   Quiet module	output

       --ui
	   Force launching GUI dialog

   Parameters:
       input=nameA [required]
	   Name	of input raster	map

       output=nameA [required]
	   Name	for output raster map containing morphometric parameter

       slope_tolerance=float
	   Slope tolerance that	defines	a 'flat' surface (degrees)
	   Default: 1.0

       curvature_tolerance=float
	   Curvature tolerance that defines 'planar' surface
	   Default: 0.0001

       size=integer
	   Size	of processing window (odd number only)
	   Options: 3-499
	   Default: 3

       method=string
	   Morphometric	parameter in 'size' window to calculate
	   Options:  elev,  slope,  aspect, profc, planc, longc, crosc,	minic,
	   maxic, feature
	   Default: elev

       exponent=float
	   Exponent for	distance weighting (0.0-4.0)
	   Default: 0.0

       zscale=float
	   Vertical scaling factor
	   Default: 1.0

DESCRIPTION
       r.param.scale extracts terrain  parameters  from	 a  digital  elevation
       model.  Uses  a	multi-scale  approach by fitting a bivariate quadratic
       polynomial to a given window size using least squares.

       The module calculates the following  parameters	(terminology  is  from
       Wood,  1996 with	related	terminology used in other GRASS	modules	listed
       in brackets):

	   o   elev: Generalised elevation value (for resampling  purposes  at
	       different scale)

	   o   slope: Magnitude	of maximum gradient (steepest slope angle)

	   o   aspect:	Direction  of  maximum gradient	(steepest slope	direc-
	       tion=flow direction)

	   o   profc: profile curvature	(curvature intersecting	with the plane
	       defined	by  Z  axis  and maximum gradient direction). Positive
	       values describe convex profile curvature, negative values  con-
	       cave profile curvature.

	   o   planc:  plan curvature (horizontal curvature, intersecting with
	       the XY plane)

	   o   longc: longitudinal curvature (profile  curvature  intersecting
	       with the	plane defined by the surface normal and	maximum	gradi-
	       ent direction)

	   o   crosc: cross-sectional curvature	(tangential  curvature	inter-
	       secting with the	plane defined by the surface normal and	a tan-
	       gent to the contour - perpendicular to maximum gradient	direc-
	       tion)

	   o   maxic: maximum curvature	(can be	in any direction)

	   o   minic: minimum curvature	(in direction perpendicular to the di-
	       rection of of maximum curvature)

	   o   feature:	Morphometric features: peaks,  ridges,	passes,	 chan-
	       nels, pits and planes

NOTES
       In  r.param.scale  the direction	of maximum gradient (considered	downs-
       lope) is	stored as (West	is 0 degree, East is +/- 180 degree):

	   o   0..+180 degree from West	to North to East

	   o   0..-180 degree from West	to South to East
       Note that the aspect map	is calculated differently from r.slope.aspect.

EXAMPLE
       The next	commands will create a geomorphological	map of	the  Spearfish
       sample dataset region:
       g.region	raster=elevation.10m -p
       r.param.scale in=elevation.10m output=morphology	method=feature size=9
       Figure: Geomorphological	map of a subregion in the Spearfish (SD) area

TODO
       Fix  bug	 when `constrain through central cell' option selected.	Create
       color tables for	all output files (presently only on features).

REFERENCES
	   o   Wood, J.	(1996):	The Geomorphological characterisation of Digi-
	       tal  Elevation  Models. Diss., Department of Geography, Univer-
	       sity of Leicester, U.K
	       online at: http://hdl.handle.net/2381/34503

	   o   Java Code in LandSerf that implements the same procedure

SEE ALSO
	r.geomorphon, r.slope.aspect

AUTHORS
       jwo@le.ac.uk - ASSIST's home

       Update to FP 3/2002: L. Potrich,	M. Neteler, S. Menegon (ITC-irst)

SOURCE CODE
       Available at: r.param.scale source code (history)

       Main index | Raster index | Topics index	| Keywords index  |  Graphical
       index | Full index

       A(C) 2003-2020 GRASS Development	Team, GRASS GIS	7.8.3 Reference	Manual

GRASS 7.8.3						      r.param.scale(1)

NAME | KEYWORDS | SYNOPSIS | DESCRIPTION | NOTES | EXAMPLE | TODO | REFERENCES | SEE ALSO | AUTHORS | SOURCE CODE

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=r.param.scale&sektion=1&manpath=FreeBSD+12.2-RELEASE+and+Ports>

home | help