.TH r.param.scale 1grass "" "GRASS 6.4.4" "Grass User's Manual"
.SH NAME
\fI\fBr.param.scale\fR\fR  - Extracts terrain parameters from a DEM.
.br
Uses a multi-scale approach by taking fitting quadratic parameters to any size window (via least squares).
.SH KEYWORDS
raster, geomorphology
.SH SYNOPSIS
\fBr.param.scale\fR
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\fBr.param.scale help\fR
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\fBr.param.scale\fR [\-\fBc\fR] \fBinput\fR=\fIname\fR \fBoutput\fR=\fIname\fR  [\fBs_tol\fR=\fIfloat\fR]   [\fBc_tol\fR=\fIfloat\fR]   [\fBsize\fR=\fIinteger\fR]   [\fBparam\fR=\fIstring\fR]   [\fBexp\fR=\fIfloat\fR]   [\fBzscale\fR=\fIfloat\fR]   [\-\-\fBoverwrite\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR] 
.SS Flags:
.IP "\fB\-c\fR" 4m
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Constrain model through central window cell
.IP "\fB\-\-overwrite\fR" 4m
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Allow output files to overwrite existing files
.IP "\fB\-\-verbose\fR" 4m
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Verbose module output
.IP "\fB\-\-quiet\fR" 4m
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Quiet module output
.PP
.SS Parameters:
.IP "\fBinput\fR=\fIname\fR" 4m
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Name of input raster map
.IP "\fBoutput\fR=\fIname\fR" 4m
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Output raster layer containing morphometric parameter
.IP "\fBs_tol\fR=\fIfloat\fR" 4m
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Slope tolerance that defines a 'flat' surface (degrees)
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Default: \fI1.0\fR
.IP "\fBc_tol\fR=\fIfloat\fR" 4m
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Curvature tolerance that defines 'planar' surface
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Default: \fI0.0001\fR
.IP "\fBsize\fR=\fIinteger\fR" 4m
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Size of processing window (odd number only, max: 69)
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Default: \fI3\fR
.IP "\fBparam\fR=\fIstring\fR" 4m
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Morphometric parameter in 'size' window to calculate
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Options: \fIelev,slope,aspect,profc,planc,longc,crosc,minic,maxic,feature\fR
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Default: \fIelev\fR
.IP "\fBexp\fR=\fIfloat\fR" 4m
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Exponent for distance weighting (0.0-4.0)
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Default: \fI0.0\fR
.IP "\fBzscale\fR=\fIfloat\fR" 4m
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Vertical scaling factor
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Default: \fI1.0\fR
.PP
.SH DESCRIPTION
\fBr.param.scale\fR 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.
.PP
The module calculates the following parameters (terminology is from Wood,
1996 with related terminology used in other GRASS modules listed in
brackets):
.RS
.IP
\fIelev\fR: Generalised elevation value (for resampling purposes at different
scale)
.IP
\fIslope\fR: Magnitude of maximum gradient (steepest slope angle)
.IP
\fIaspect\fR: Direction of maximum gradient (steepest slope direction=flow direction)
.IP
\fIprofc\fR or profile curvature (curvature intersecting with the plane
defined by \fIZ\fR axis and maximum gradient direction). Positive values
describe convex profile curvature, negative values concave profile
curvature.
.IP
\fIplanc\fR or plan curvature (horizontal curvature, intersecting with
the \fIXY\fR plane)
.IP
\fIlongc\fR or longitudinal curvature (profile curvature intersecting
with the plane defined by the surface normal and maximum gradient direction)
.IP
\fIcrosc\fR 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)
.IP
\fImaxic\fR or maximum curvature (can be in any direction)
.IP
\fIminic\fR or minimum curvature (in direction perpendicular to the direction
of of maximum curvature)
.IP
\fIfeature\fR: Morphometric features: peaks, ridges, passes, channels, pits and planes
.RE
.SH NOTES
In \fIr.param.scale\fR the direction of maximum gradient (considered
downslope) is stored as (West is 0 degree, East is +/- 180 degree):
.RS
.IP
0..+180 degree from West to North to East
.IP
0..-180 degree from West to South to East
.RE
Note that the aspect map is calculated differently from
r.slope.aspect.
.SH Still to do
Fix bug when \(gaconstrain through central cell' option selected. Create color
tables for all output files (presently only on features).
.SH EXAMPLE
The next commands will create a geomorphological map of the Spearfish region:
\fC
.DS
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g.region rast=elevation.10m \-p
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r.param.scale in=elevation.10m output=morphology param=feature size=9
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d.mon x0
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d.rast.leg morphology
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.DE
\fR
.PP
\fIGeomorphological map of a subregion in the Spearfish (SD) area\fR
.SH SEE ALSO
.PP
Java Code in
LandSerf
that implements the same procedure
.SH REFERENCE
Wood, J. (1996): The Geomorphological characterisation of Digital Elevation
Models. Diss., Department of Geography, University of Leicester, U.K.
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online at:
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http://www.soi.city.ac.uk/~jwo/phd/
.SH AUTHOR
jwo@le.ac.uk
- ASSIST's home
.PP
Update to FP 3/2002: L. Potrich, M. Neteler, S. Menegon (ITC-irst)
.PP
\fILast changed: $Date: 2009-04-03 09:17:56 +0200 (Fri, 03 Apr 2009) $\fR
.PP
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