SAGA 9.4.2 | Tool Library Documentation

SaLEM

Description

This is the implementation of a Soil and Landscape Evolution Model (SaLEM) for the spatiotemporal investigation of soil parent material evolution following a lithologically differentiated approach. The model needs a digital elevation model and (paleo-)climatic data for the simulation of weathering, erosion and transport processes. Weathering is controlled by user defined functions in dependence of climate conditions, local slope, regolith cover and outcropping bedrock lithology. Lithology can be supplied as a set of grids, of which each grid represents the top elevation of the underlying bedrock type.

References

Parameters

 NameTypeIdentifierDescriptionConstraints
InputInitial Surface Elevationgrid, inputSURFACE_T0--
Initial Regolith Thicknessgrid, input, optionalREGOLITH_T0Initial sediment cover (m)-
Allochthone Inputgrid, input, optionalALLOCHTHONEAllochthone input in meter per year (e.g. of aeolian origin, 'Loess').-
Long-term Temperature Signaltable, inputTRENDLong-term temperature signal, used as adjustment for annual scenarios, i.e. to let their original values appear cooler or warmer.-
Annual Climatetable, inputANNUAL--
Lithologygrid list, input, optionalROCK_LAYERS--
OutputSurface Elevationgrid, outputSURFACE--
Regolith Thicknessgrid, outputREGOLITH--
Differencegrid, outputDIFFERENCE--
Tracershapes, output, optionalPOINTS--
Tracer Pathsshapes, output, optionalLINES--
OptionsGrid Systemgrid systemPARAMETERS_GRID_SYSTEM--
Defaultfloating point numberREGOLITH_T0_DEFAULTdefault value if no grid has been selectedMinimum: 0.000000 Default: 0.000000
Defaultfloating point numberALLOCHTHONE_DEFAULTdefault value if no grid has been selectedMinimum: 0.000000 Default: 0.000000
Yeartable fieldTREND_YEARTime expected as 1000 years before present (ka BP).-
Temperaturetable fieldTREND_TTemperature expected as degree Celsius.-
Temperature Offsetfloating point numberTREND_T_OFFSETTemperature offset (degree Celsius).Default: 31.000000
Mean Temperaturetable fieldANNUAL_T--
Minimum Temperaturetable fieldANNUAL_TMIN--
Maximum Temperaturetable fieldANNUAL_TMAX--
Precipitationtable fieldANNUAL_P--
Temperature UnitchoiceANNUAL_T_UNIT-Available Choices: [0] Celsius [1] Kelvin Default: 0
Temperature Lapse Ratefloating point numberT_LAPSETemperature lapse rate as degree Celsius per 100 meter.Minimum: 0.000000 Default: 0.600000
Temperature Height CorrectionbooleanT_LAPSE_CELLCellwise temperature correction applying specified temperature lapse rate to surface elevation.Default: 1
Weathering Formulasstatic tableWEATHERINGVariables that can be used in formulas are 'T', 'Tmin', 'Tmax', 'Tamp' (mean, minimum, maximum, range of temperature), 'P' (precipitation), 'R' (regolith thickness), 'S' (slope gradient).2 Fields: - 1. [string] Frost - 2. [string] Chemical
Frost WeatheringtextFROST-Default: 0.0250 * (0.00175 * R + T - Tmax) / (-Tamp * cos(S))
Chemical WeatheringtextCHEMICAL-Default: 0.0002 * exp(-5.0 * R)
TrimchoiceTRIMRemove tracers and associated paths that moved out of the investigated area (performance gain).Available Choices: [0] no [1] temporarily [2] permanently Default: 1
Randomize Directionfloating point numberDIR_RANDUncertainty in routing direction expressed as standard deviation (degree).Minimum: 0.000000 Default: 0.000000
Horizontal Densityinteger numberH_DENSITYHorizontal tracer density in cells.Minimum: 1 Default: 1
RandomizebooleanH_RANDOM-Default: 1
Vertical Densityfloating point numberV_DENSITYVertical tracer density in meter.Minimum: 0.010000 Default: 0.500000
RandomizebooleanV_RANDOM-Default: 1
Start [Years BP]integer numberTIME_START-Default: 50000
Stop [Years BP]integer numberTIME_STOP-Default: 10000
Step [Years]integer numberTIME_STEP-Minimum: 1 Default: 100
Diffusivity Coefficient Kd [m_/a]floating point numberDIFFUSIVE_KD-Minimum: 0.000000 Default: 0.010000
NeighbourhoodchoiceDIFFUSIVE_NEIGHBOURS-Available Choices: [0] Neumann [1] Moore Default: 1

Command Line


Usage: saga_cmd sim_landscape_evolution 0 [-SURFACE_T0 ] [-REGOLITH_T0 ] [-REGOLITH_T0_DEFAULT ] [-ALLOCHTHONE ] [-ALLOCHTHONE_DEFAULT ] [-SURFACE ] [-REGOLITH ] [-DIFFERENCE ] [-CLIMATE_TREND ] [-CLIMATE_TREND_YEAR ] [-CLIMATE_TREND_T ] [-CLIMATE_TREND_T_OFFSET ] [-CLIMATE_ANNUAL ] [-CLIMATE_ANNUAL_T ] [-CLIMATE_ANNUAL_TMIN ] [-CLIMATE_ANNUAL_TMAX ] [-CLIMATE_ANNUAL_P ] [-CLIMATE_ANNUAL_T_UNIT ] [-CLIMATE_T_LAPSE ] [-CLIMATE_T_LAPSE_CELL ] [-BEDROCK_ROCK_LAYERS ] [-BEDROCK_WEATHERING ] [-BEDROCK_FROST ] [-BEDROCK_CHEMICAL ] [-TRACERS_POINTS ] [-TRACERS_LINES ] [-TRACERS_TRIM ] [-TRACERS_DIR_RAND ] [-TRACERS_H_DENSITY ] [-TRACERS_H_RANDOM ] [-TRACERS_V_DENSITY ] [-TRACERS_V_RANDOM ] [-TIME_START ] [-TIME_STOP ] [-TIME_STEP ] [-DIFFUSIVE_KD ] [-DIFFUSIVE_NEIGHBOURS ]
  -SURFACE_T0:               	Initial Surface Elevation
	grid, input
  -REGOLITH_T0:              	Initial Regolith Thickness
	grid, input, optional
  -REGOLITH_T0_DEFAULT:   	Default
	floating point number
	Minimum: 0.000000
	Default: 0.000000
  -ALLOCHTHONE:              	Allochthone Input
	grid, input, optional
  -ALLOCHTHONE_DEFAULT:   	Default
	floating point number
	Minimum: 0.000000
	Default: 0.000000
  -SURFACE:                  	Surface Elevation
	grid, output
  -REGOLITH:                 	Regolith Thickness
	grid, output
  -DIFFERENCE:               	Difference
	grid, output
  -CLIMATE_TREND:            	Long-term Temperature Signal
	table, input
  -CLIMATE_TREND_YEAR:       	Year
	table field
  -CLIMATE_TREND_T:          	Temperature
	table field
  -CLIMATE_TREND_T_OFFSET:	Temperature Offset
	floating point number
	Default: 31.000000
  -CLIMATE_ANNUAL:           	Annual Climate
	table, input
  -CLIMATE_ANNUAL_T:         	Mean Temperature
	table field
  -CLIMATE_ANNUAL_TMIN:      	Minimum Temperature
	table field
  -CLIMATE_ANNUAL_TMAX:      	Maximum Temperature
	table field
  -CLIMATE_ANNUAL_P:         	Precipitation
	table field
  -CLIMATE_ANNUAL_T_UNIT:    	Temperature Unit
	choice
	Available Choices:
	[0] Celsius
	[1] Kelvin
	Default: 0
  -CLIMATE_T_LAPSE:       	Temperature Lapse Rate
	floating point number
	Minimum: 0.000000
	Default: 0.600000
  -CLIMATE_T_LAPSE_CELL:     	Temperature Height Correction
	boolean
	Default: 1
  -BEDROCK_ROCK_LAYERS:      	Lithology
	grid list, input, optional
  -BEDROCK_WEATHERING:       	Weathering Formulas
	static table
	2 Fields:
	- 1. [string] Frost
	- 2. [string] Chemical
	
  -BEDROCK_FROST:            	Frost Weathering
	text
	Default: 0.0250 * (0.00175 * R + T - Tmax) / (-Tamp * cos(S))
  -BEDROCK_CHEMICAL:         	Chemical Weathering
	text
	Default: 0.0002 * exp(-5.0 * R)
  -TRACERS_POINTS:           	Tracer
	shapes, output, optional
  -TRACERS_LINES:            	Tracer Paths
	shapes, output, optional
  -TRACERS_TRIM:             	Trim
	choice
	Available Choices:
	[0] no
	[1] temporarily
	[2] permanently
	Default: 1
  -TRACERS_DIR_RAND:      	Randomize Direction
	floating point number
	Minimum: 0.000000
	Default: 0.000000
  -TRACERS_H_DENSITY:        	Horizontal Density
	integer number
	Minimum: 1
	Default: 1
  -TRACERS_H_RANDOM:         	Randomize
	boolean
	Default: 1
  -TRACERS_V_DENSITY:     	Vertical Density
	floating point number
	Minimum: 0.010000
	Default: 0.500000
  -TRACERS_V_RANDOM:         	Randomize
	boolean
	Default: 1
  -TIME_START:               	Start [Years BP]
	integer number
	Default: 50000
  -TIME_STOP:                	Stop [Years BP]
	integer number
	Default: 10000
  -TIME_STEP:                	Step [Years]
	integer number
	Minimum: 1
	Default: 100
  -DIFFUSIVE_KD:          	Diffusivity Coefficient Kd [m_/a]
	floating point number
	Minimum: 0.000000
	Default: 0.010000
  -DIFFUSIVE_NEIGHBOURS:     	Neighbourhood
	choice
	Available Choices:
	[0] Neumann
	[1] Moore
	Default: 1