r.param.scale(1)

1r.param.scale(1)              Grass User's Manual             r.param.scale(1)
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NAME

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

11       raster, geomorphology
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SYNOPSIS

14       r.param.scale
15       r.param.scale help
16       r.param.scale    [-c]     input=name     output=name      [s_tol=float]
17       [c_tol=float]       [size=integer]      [param=string]      [exp=float]
18       [zscale=float]   [--overwrite]  [--verbose]  [--quiet]
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20   Flags:
21       -c
22           Constrain model through central window cell
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24       --overwrite
25           Allow output files to overwrite existing files
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27       --verbose
28           Verbose module output
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30       --quiet
31           Quiet module output
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33   Parameters:
34       input=name
35           Name of input raster map
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37       output=name
38           Output raster layer containing morphometric parameter
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40       s_tol=float
41           Slope tolerance that defines a 'flat' surface (degrees)
42           Default: 1.0
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44       c_tol=float
45           Curvature tolerance that defines 'planar' surface
46           Default: 0.0001
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48       size=integer
49           Size of processing window (odd number only, max: 69)
50           Default: 3
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52       param=string
53           Morphometric parameter in 'size' window to calculate
54           Options: elev,slope,aspect,profc,planc,longc,crosc,minic,maxic,fea‐
55           ture
56           Default: elev
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58       exp=float
59           Exponent for distance weighting (0.0-4.0)
60           Default: 0.0
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62       zscale=float
63           Vertical scaling factor
64           Default: 1.0
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DESCRIPTION

67       r.param.scale  extracts  terrain  parameters  from a DEM. Uses a multi-
68       scale approach by fitting a bivariate quadratic polynomial to  a  given
69       window size using least squares.
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71       The  module  calculates  the  following parameters (terminology is from
72       Wood, 1996 with related terminology used in other GRASS modules  listed
73       in brackets):
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75                     elev:  Generalised  elevation  value (for resampling pur‐
76                     poses at different scale)
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78                     slope: Magnitude  of  maximum  gradient  (steepest  slope
79                     angle)
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81                     aspect:  Direction  of  maximum  gradient (steepest slope
82                     direction=flow direction)
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84                     profc or profile curvature (curvature  intersecting  with
85                     the  plane  defined by Z axis and maximum gradient direc‐
86                     tion). Positive values describe convex profile curvature,
87                     negative values concave profile curvature.
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89                     planc or plan curvature (horizontal curvature, intersect‐
90                     ing with the XY plane)
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92                     longc or longitudinal curvature (profile curvature inter‐
93                     secting  with the plane defined by the surface normal and
94                     maximum gradient direction)
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96                     crosc or cross-sectional curvature (tangential  curvature
97                     intersecting with the plane defined by the surface normal
98                     and a tangent to the contour - perpendicular  to  maximum
99                     gradient direction)
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101                     maxic or maximum curvature (can be in any direction)
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103                     minic or minimum curvature (in direction perpendicular to
104                     the direction of of maximum curvature)
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106                     feature: Morphometric features:  peaks,  ridges,  passes,
107                     channels, pits and planes
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NOTES

110       In  r.param.scale  the direction of maximum gradient (considered downs‐
111       lope) is stored as (West is 0 degree, East is +/- 180 degree):
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113                     0..+180 degree from West to North to East
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115                     0..-180 degree from West to South to East
116       Note that the aspect map is calculated differently from r.slope.aspect.
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Still to do

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

123       The next commands will create a morphology map of the Spearfish region:
124       g.region rast=elevation.10m -p
125       r.param.scale in=elevation.10m output=morphology param=feature
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REFERENCE

132       Wood,  J. (1996): The Geomorphological characterisation of Digital Ele‐
133       vation Models. Diss., Department of Geography, University of Leicester,
134       U.K.
135       online at:
136       http://www.soi.city.ac.uk/~jwo/phd/
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AUTHOR

139       jwo@le.ac.uk - ASSIST's home
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141       Update to FP 3/2002: L. Potrich, M. Neteler, S. Menegon (ITC-irst)
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143       Last changed: $Date: 2006-07-15 20:23:43 +0200 (Sat, 15 Jul 2006) $
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145       Full index
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147       © 2003-2008 GRASS Development Team
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151GRASS 6.3.0                                                   r.param.scale(1)