SaLEM

Author: M.Bock, O.Conrad (c) 2017
Menu: Simulation | Landscape Evolution

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

Alley, R. (2000): The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19: 213-226.
Bock, M., Conrad, O., Guenther, A., Gehrt, E., Baritz, R., and Boehner, J. (2018): SaLEM (v1.0) - the Soil and Landscape Evolution Model (SaLEM) for simulation of regolith depth in periglacial environments. Geosci. Model Dev., 11, 1641-1652. https://doi.org/10.5194/gmd-11-1641-2018.
Tucker, G.E. & Slingerland, R. (1994): Erosional dynamics, flexural isostasy, and long-lived escarpments: A numerical modeling study. Journal of Geophysical Research 99: 12229-12243.

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Initial Surface Elevation	grid, input	`SURFACE_T0`	-	-
	Initial Regolith Thickness	grid, input, optional	`REGOLITH_T0`	Initial sediment cover (m)	-
	Allochthone Input	grid, input, optional	`ALLOCHTHONE`	Allochthone input in meter per year (e.g. of aeolian origin, 'Loess').	-
	Long-term Temperature Signal	table, input	`TREND`	Long-term temperature signal, used as adjustment for annual scenarios, i.e. to let their original values appear cooler or warmer.	-
	Annual Climate	table, input	`ANNUAL`	-	-
	Lithology	grid list, input, optional	`ROCK_LAYERS`	-	-
Output	Surface Elevation	grid, output	`SURFACE`	-	-
	Regolith Thickness	grid, output	`REGOLITH`	-	-
	Difference	grid, output	`DIFFERENCE`	-	-
	Tracer	shapes, output, optional	`POINTS`	-	-
	Tracer Paths	shapes, output, optional	`LINES`	-	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Default	floating point number	`REGOLITH_T0_DEFAULT`	default value if no grid has been selected	Minimum: 0.000000 Default: 0.000000
	Default	floating point number	`ALLOCHTHONE_DEFAULT`	default value if no grid has been selected	Minimum: 0.000000 Default: 0.000000
	Year	table field	`TREND_YEAR`	Time expected as 1000 years before present (ka BP).	-
	Temperature	table field	`TREND_T`	Temperature expected as degree Celsius.	-
	Temperature Offset	floating point number	`TREND_T_OFFSET`	Temperature offset (degree Celsius).	Default: 31.000000
	Mean Temperature	table field	`ANNUAL_T`	-	-
	Minimum Temperature	table field	`ANNUAL_TMIN`	-	-
	Maximum Temperature	table field	`ANNUAL_TMAX`	-	-
	Precipitation	table field	`ANNUAL_P`	-	-
	Temperature Unit	choice	`ANNUAL_T_UNIT`	-	Available Choices: [0] Celsius [1] Kelvin Default: 0
	Temperature Lapse Rate	floating point number	`T_LAPSE`	Temperature lapse rate as degree Celsius per 100 meter.	Minimum: 0.000000 Default: 0.600000
	Temperature Height Correction	boolean	`T_LAPSE_CELL`	Cellwise temperature correction applying specified temperature lapse rate to surface elevation.	Default: 1
	Weathering Formulas	static table	`WEATHERING`	Variables 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 Weathering	text	`FROST`	-	Default: 0.0250 * (0.00175 * R + T - Tmax) / (-Tamp * cos(S))
	Chemical Weathering	text	`CHEMICAL`	-	Default: 0.0002 * exp(-5.0 * R)
	Trim	choice	`TRIM`	Remove tracers and associated paths that moved out of the investigated area (performance gain).	Available Choices: [0] no [1] temporarily [2] permanently Default: 1
	Randomize Direction	floating point number	`DIR_RAND`	Uncertainty in routing direction expressed as standard deviation (degree).	Minimum: 0.000000 Default: 0.000000
	Horizontal Density	integer number	`H_DENSITY`	Horizontal tracer density in cells.	Minimum: 1 Default: 1
	Randomize	boolean	`H_RANDOM`	-	Default: 1
	Vertical Density	floating point number	`V_DENSITY`	Vertical tracer density in meter.	Minimum: 0.010000 Default: 0.500000
	Randomize	boolean	`V_RANDOM`	-	Default: 1
	Start [Years BP]	integer number	`TIME_START`	-	Default: 50000
	Stop [Years BP]	integer number	`TIME_STOP`	-	Default: 10000
	Step [Years]	integer number	`TIME_STEP`	-	Minimum: 1 Default: 100
	Diffusivity Coefficient Kd [m_/a]	floating point number	`DIFFUSIVE_KD`	-	Minimum: 0.000000 Default: 0.010000
	Neighbourhood	choice	`DIFFUSIVE_NEIGHBOURS`	-	Available Choices: [0] Neumann [1] Moore Default: 1
	Display Update Frequency	integer number	`UPDATE`	The frequency (simulation time steps) with which associated maps will be updated. Set to zero to switch off.	Minimum: 0 Default: 1
	Vectors	boolean	`UPDATE_VEC`	-	Default: 1
	Adjust Regolith	boolean	`UPDATE_ADJ`	-	Default: 1
	Minimum	floating point number	`UPDATE_MIN`	-	Minimum: 0.000000 Default: 0.000000
	Maximum	floating point number	`UPDATE_MAX`	-	Minimum: 0.000000 Default: 2.000000

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 ] [-UPDATE ] [-UPDATE_VEC ] [-UPDATE_ADJ ] [-UPDATE_MIN ] [-UPDATE_MAX ]
  -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
  -UPDATE:                   	Display Update Frequency
	integer number
	Minimum: 0
	Default: 1
  -UPDATE_VEC:               	Vectors
	boolean
	Default: 1
  -UPDATE_ADJ:               	Adjust Regolith
	boolean
	Default: 1
  -UPDATE_MIN:            	Minimum
	floating point number
	Minimum: 0.000000
	Default: 0.000000
  -UPDATE_MAX:            	Maximum
	floating point number
	Minimum: 0.000000
	Default: 2.000000