RSAGA (version 1.4.0)

rsaga.local.morphometry: Local Morphometry

Description

Calculates local morphometric terrain attributes (i.e. slope, aspect and curvatures). Intended for use with SAGA versions 2.1.0 and older. Use rsaga.slope.asp.curv() for SAGA 2.1.1+

Usage

rsaga.local.morphometry(
  in.dem,
  out.slope,
  out.aspect,
  out.curv,
  out.hcurv,
  out.vcurv,
  method = "poly2zevenbergen",
  env = rsaga.env(),
  ...
)
rsaga.slope(
  in.dem,
  out.slope,
  method = "poly2zevenbergen",
  env = rsaga.env(),
  ...
)
rsaga.aspect(
  in.dem,
  out.aspect,
  method = "poly2zevenbergen",
  env = rsaga.env(),
  ...
)
rsaga.curvature(
  in.dem,
  out.curv,
  method = "poly2zevenbergen",
  env = rsaga.env(),
  ...
)
rsaga.plan.curvature(
  in.dem,
  out.hcurv,
  method = "poly2zevenbergen",
  env = rsaga.env(),
  ...
)
rsaga.profile.curvature(
  in.dem,
  out.vcurv,
  method = "poly2zevenbergen",
  env = rsaga.env(),
  ...
)

Value

The type of object returned depends on the intern argument passed to the rsaga.geoprocessor(). For intern=FALSE it is a numerical error code (0: success), or otherwise (default) a character vector with the module's console output.

Arguments

in.dem

input: digital elevation model (DEM) as SAGA grid file (default file extension: .sgrd)

out.slope

optional output: slope (in radians)

out.aspect

optional output: aspect (in radians; north=0, clockwise angles)

out.curv

optional output: curvature

out.hcurv

optional output: horizontal curvature (plan curvature)

out.vcurv

optional output: vertical curvature (profile curvature)

method

character (or numeric): algorithm (see References):

• 0 Maximum Slope - Travis et al. (1975) ("maxslope", or 0)

• 1 Max. Triangle Slope - Tarboton (1997) ("maxtriangleslope", or 1)

• 2 Least Squares Fit Plane - Costa-Cabral and Burgess (1996) ("lsqfitplane", or 2)

• 3 Fit 2nd Degree Polynomial - Bauer et al. (1985) ("poly2bauer", or 3)

• 4 Fit 2nd Degree Polynomial - Heerdegen and Beran (1982) ("poly2heerdegen", or 4)

• 5 default: Fit 2nd Degree Polynomial - Zevenbergen and Thorne (1987) ("poly2zevenbergen", or 5)

• 6 Fit 3rd Degree Polynomial - Haralick (1983) ("poly3haralick", or 6).

env

list, setting up a SAGA geoprocessing environment as created by rsaga.env()

...

further arguments to rsaga.geoprocessor()

Author

Alexander Brenning and Donovan Bangs (R interface), Olaf Conrad (SAGA module)

References

For references and algorithm changes in SAGA GIS 2.1.1+ see rsaga.slope.asp.curv().

See Also

rsaga.slope.asp.curv(), rsaga.parallel.processing(), rsaga.geoprocessor(), rsaga.env()

Examples

if (FALSE) {
# a simple slope algorithm:
rsaga.slope("lican.sgrd","slope","maxslope")
# same for ASCII grids (default extension .asc):
rsaga.esri.wrapper(rsaga.slope,in.dem="lican",out.slope="slope",method="maxslope")
}