Module WEDGEFAIL

This module determines terrain elements where failure (slide- or topple movements) on geological discontinuies are kinematically possible through the spatial application of common frictional feasibility criteria (Günther et al. 2012 and references therein). Both the orientation of slope elements specified through aspect- and dip grids (in radians) are required together with the orientation of one planar structure defined through global- or grid dip direction and dip data, or two planar structures defined by plunge direction and plunge information of their intersection line (in degrees). The shear strength of the discontinuities is specified using global or grid-based friction angle data. Optionally, a cone value can be set allowing for some variance in discontinuity dip orientations. The tool operates in slide (testing for plane and wedge sliding) or topple (testing for plane and wedge toppling) modes.

Reference:
Günther A., Wienhöfer J., Konietzky H. (2012) Automated mapping of rock slope geometry, kinematics and stability with RSS-GIS. Natural Hazards, 61, 29-49..

Author: A. Günther (c) 2012
Specification: grid
Menu: Terrain Analysis|Slope Stability

Parameters

	Name	Type	Identifier	Description	Constraints
Input	DEM	Grid (input)	`DEM`	A DEM	-
	Dip/Plunge direction grid (degree) (*)	Grid (optional input)	`C`	A dip- or plunge direction grid (in degrees)	-
	Dip/Plunge grid (degree) (*)	Grid (optional input)	`D`	A dip- or plunge grid (in degrees)	-
	Min friction angle grid (degree) (*)	Grid (optional input)	`Emin`	A minimum discontinuity friction angle grid (in degrees)	-
	Max friction angle grid (degree) (*)	Grid (optional input)	`Emax`	A maximum discontinuity friction angle grid (in degrees)	-
Output	Failures	Grid (output)	`F`	Resulting failure cells (-) grid	-
Options	Global dip/plunge direction (degree)	Floating point	`fC`	Constant value if no raster set	Default: 0.000000
	Global dip/plunge (degree)	Floating point	`fD`	Constant value if no raster set	Default: 35.000000
	Min global friction angle (degree)	Floating point	`fEmin`	Constant value if no raster set	Default: 35.000000
	Max global friction angle (degree)	Floating point	`fEmax`	Constant value if no raster set	Default: 35.000000
	Cone radius (degree)	Integer	`ff`	Radius of optional cone variance (in degrees)	Default: 0
	Parameter sampling runs	Integer	`fI`	Number of sampling cycles	Default: 1
	Mode	Choice	`METHOD`	Set failure mode	Available Choices: [0] Slide [1] Topple Default: 0
(*) optional

Command-line

Usage: saga_cmd ta_slope_stability 4 [-DEM <str>] [-C <str>] [-D <str>] [-Emin <str>] [-Emax <str>] [-fC <str>] [-fD <str>] [-fEmin <str>] [-fEmax <str>] [-ff <num>] [-F <str>] [-fI <num>] [-METHOD <str>]
  -DEM:<str>   	DEM
	Grid (input)
  -C:<str>     	Dip/Plunge direction grid (degree) 
	Grid (optional input)
  -D:<str>     	Dip/Plunge grid (degree) 
	Grid (optional input)
  -Emin:<str>  	Min friction angle grid (degree) 
	Grid (optional input)
  -Emax:<str>  	Max friction angle grid (degree) 
	Grid (optional input)
  -fC:<str>    	Global dip/plunge direction (degree)
	Floating point
	Default: 0.000000
  -fD:<str>    	Global dip/plunge (degree)
	Floating point
	Default: 35.000000
  -fEmin:<str> 	Min global friction angle (degree)
	Floating point
	Default: 35.000000
  -fEmax:<str> 	Max global friction angle (degree)
	Floating point
	Default: 35.000000
  -ff:<num>    	Cone radius (degree)
	Integer
	Default: 0
  -F:<str>     	Failures
	Grid (output)
  -fI:<num>    	Parameter sampling runs
	Integer
	Default: 1
  -METHOD:<str>	Mode
	Choice
	Available Choices:
	[0] Slide
	[1] Topple
	Default: 0