Tool SAFETYFACTOR
This tool computes a slope stability (expressed as a factor-of-safety) raster according to the traditional infinite slope model theory (see cf Selby, 1993) The resulting raster represents the ratio of resisting forces/driving forces (fs) on a potential shear plane with fs lesser 1 unstable, fs greater 1 stable. Except for a slope raster (in radians), all input variables can be specified either globally or distributed (through grids). The tool creates a continuous fs raster (values above 10 are truncated), and a binary stability grid with nodata = stable, 1 = unstable (optional).
- Author: A. Günther (c) 2012
- Menu: Terrain Analysis|Slope Stability
Parameters
| Name | Type | Identifier | Description | Constraints | |
|---|---|---|---|---|---|
| Input | Slope grid (rad) | Grid (input) | A | - | - |
| Min thickness grid (m) (*) | Grid (optional input) | Bmin | A grid representing minimum cell layer thicknesses to potential shear plane (in meters) | - | |
| Max thickness grid (m) (*) | Grid (optional input) | Bmax | A grid representing maximum cell layer thicknesses to potential shear plane (in meters) | - | |
| Min saturation grid (-) (*) | Grid (optional input) | Cmin | A grid representing minimum cell relative water saturation of layer (dimensionless) | - | |
| Max saturation grid (-) (*) | Grid (optional input) | Cmax | A grid representing maximum cell relative water saturation of layer (dimensionless) | - | |
| Min friction grid (degree) (*) | Grid (optional input) | Dmin | A grid representing minimum cell frictional shear strength of layer (in degrees) | - | |
| Max friction grid (degree) (*) | Grid (optional input) | Dmax | A grid representing maximum cell frictional shear strength of layer (in degrees) | - | |
| Min density grid (g/cm3) (*) | Grid (optional input) | Emin | A grid representing minimum cell bulk density of layer (in grams per cubiccentimeters) | - | |
| Max density grid (g/cm3) (*) | Grid (optional input) | Emax | A grid representing maximum cell bulk density of layer (in grams per cubiccentimeters) | - | |
| Min cohesion grid (MPa) (*) | Grid (optional input) | Fmin | A grid representing minimum cell layer cohesion (in Megapascals) | - | |
| Max cohesion grid (MPa) (*) | Grid (optional input) | Fmax | A grid representing maximum cell layer cohesion (in Megapascals) | - | |
| Output | FS values | Grid (output) | G | Resulting factor-of-safety (-) grid | - |
| FS classes (*) | Grid (optional output) | H | Resulting stability (0/1) grid | - | |
| Options | Grid system | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Min global thickness (m) | Floating point | fBmin | Constant value if no raster set | Default: 1.000000 | |
| Max global thickness (m) | Floating point | fBmax | Constant value if no raster set | Default: 1.000000 | |
| Min global saturation (-) | Floating point | fCmin | Constant value if no raster set | Default: 0.000000 | |
| Max global saturation (-) | Floating point | fCmax | Constant value if no raster set | Default: 0.000000 | |
| Min global friction (degree) | Floating point | fDmin | Constant value if no raster set | Default: 33.000000 | |
| Max global friction (degree) | Floating point | fDmax | Constant value if no raster set | Default: 33.000000 | |
| Min global density (g/cm3) | Floating point | fEmin | Constant value if no raster set | Default: 1.600000 | |
| Max global density (g/cm3) | Floating point | fEmax | Constant value if no raster set | Default: 1.600000 | |
| Min global cohesion (MPa) | Floating point | fFmin | Constant value if no raster set | Default: 0.000000 | |
| Max global cohesion (MPa) | Floating point | fFmax | Constant value if no raster set | Default: 0.000000 | |
| Parameter sampling runs | Integer | fI | Number of sampling cycles | Default: 1 | |
| (*) optional | |||||
Command-line
Usage: saga_cmd ta_slope_stability 0 [-A <str>] [-Bmin <str>] [-Bmax <str>] [-Cmin <str>] [-Cmax <str>] [-Dmin <str>] [-Dmax <str>] [-Emin <str>] [-Emax <str>] [-Fmin <str>] [-Fmax <str>] [-fBmin <double>] [-fBmax <double>] [-fCmin <double>] [-fCmax <double>] [-fDmin <double>] [-fDmax <double>] [-fEmin <double>] [-fEmax <double>] [-fFmin <double>] [-fFmax <double>] [-fI <num>] [-G <str>] [-H <str>] -A:<str> Slope grid (rad) Grid (input) -Bmin:<str> Min thickness grid (m) Grid (optional input) -Bmax:<str> Max thickness grid (m) Grid (optional input) -Cmin:<str> Min saturation grid (-) Grid (optional input) -Cmax:<str> Max saturation grid (-) Grid (optional input) -Dmin:<str> Min friction grid (degree) Grid (optional input) -Dmax:<str> Max friction grid (degree) Grid (optional input) -Emin:<str> Min density grid (g/cm3) Grid (optional input) -Emax:<str> Max density grid (g/cm3) Grid (optional input) -Fmin:<str> Min cohesion grid (MPa) Grid (optional input) -Fmax:<str> Max cohesion grid (MPa) Grid (optional input) -fBmin:<double> Min global thickness (m) Floating point Default: 1.000000 -fBmax:<double> Max global thickness (m) Floating point Default: 1.000000 -fCmin:<double> Min global saturation (-) Floating point Default: 0.000000 -fCmax:<double> Max global saturation (-) Floating point Default: 0.000000 -fDmin:<double> Min global friction (degree) Floating point Default: 33.000000 -fDmax:<double> Max global friction (degree) Floating point Default: 33.000000 -fEmin:<double> Min global density (g/cm3) Floating point Default: 1.600000 -fEmax:<double> Max global density (g/cm3) Floating point Default: 1.600000 -fFmin:<double> Min global cohesion (MPa) Floating point Default: 0.000000 -fFmax:<double> Max global cohesion (MPa) Floating point Default: 0.000000 -fI:<num> Parameter sampling runs Integer Default: 1 -G:<str> FS values Grid (output) -H:<str> FS classes Grid (optional output)