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r.param.scale.1grass
Langue: en
Version: 331361 (ubuntu - 24/10/10)
Section: 1 (Commandes utilisateur)
Sommaire
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, geomorphologySYNOPSIS
r.param.scaler.param.scale help
r.param.scale [-c] input=name output=name [s_tol=float] [c_tol=float] [size=integer] [param=string] [exp=float] [zscale=float] [--overwrite] [--verbose] [--quiet]
Flags:
- -c
Constrain model through central window cell- --overwrite
Allow output files to overwrite existing files- --verbose
Verbose module output- --quiet
Quiet module output
Parameters:
- input=name
Name of input raster map- output=name
Output raster layer containing morphometric parameter- s_tol=float
Slope tolerance that defines a 'flat' surface (degrees)
Default: 1.0- c_tol=float
Curvature tolerance that defines 'planar' surface
Default: 0.0001- size=integer
Size of processing window (odd number only, max: 69)
Default: 3- param=string
Morphometric parameter in 'size' window to calculate
Options: elev,slope,aspect,profc,planc,longc,crosc,minic,maxic,feature
Default: elev- exp=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 DEM. 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):
-
- elev: Generalised elevation value (for resampling purposes at different scale)
- slope: Magnitude of maximum gradient (steepest slope angle)
- aspect: Direction of maximum gradient (steepest slope direction=flow direction)
- profc or profile curvature (curvature intersecting with the plane defined by Z axis and maximum gradient direction). Positive values describe convex profile curvature, negative values concave profile curvature.
- planc or plan curvature (horizontal curvature, intersecting with the XY plane)
- longc or longitudinal curvature (profile curvature intersecting with the plane defined by the surface normal and maximum gradient direction)
- crosc or cross-sectional curvature (tangential curvature intersecting with the plane defined by the surface normal and a tangent to the contour - perpendicular to maximum gradient direction)
- maxic or maximum curvature (can be in any direction)
- minic or minimum curvature (in direction perpendicular to the direction of of maximum curvature)
- feature: Morphometric features: peaks, ridges, passes, channels, pits and planes
NOTES
In r.param.scale the direction of maximum gradient (considered downslope) is stored as (West is 0 degree, East is +/- 180 degree):-
- 0..+180 degree from West to North to East
- 0..-180 degree from West to South to East
Still to do
Fix bug when `constrain through central cell' option selected. Create color tables for all output files (presently only on features).EXAMPLE
The next commands will create a geomorphological map of the Spearfish region:g.region rast=elevation.10m -p
r.param.scale in=elevation.10m output=morphology param=feature size=9
d.mon x0
d.rast.leg morphology
Geomorphological map of a subregion in the Spearfish (SD) area
SEE ALSO
Java Code in LandSerf that implements the same procedure
REFERENCE
Wood, J. (1996): The Geomorphological characterisation of Digital Elevation Models. Diss., Department of Geography, University of Leicester, U.K.online at:
http://www.soi.city.ac.uk/~jwo/phd/
AUTHOR
jwo@le.ac.uk - ASSIST's homeUpdate to FP 3/2002: L. Potrich, M. Neteler, S. Menegon (ITC-irst)
Last changed: $Date: 2009-04-03 09:17:56 +0200 (ven, 03 apr 2009) $
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