Tool Soil Water Simulation after Glugla (Grid)

A simple model for daily soil water simulation based on the approach of Glugla (1969).

This is a re-implementation of the formulas used in the 'Simpel' model developed by Hoermann (1998), "...covering the lowest, serious end of hydrologic computing".

References

Simpel Homepage
Glugla, G. (1969): Berechnungsverfahren zur Ermittlung des aktuellen Wassergehalts und Gravitationswasserabflusses im Boden. Archives of Agronomy and Soil Science, 13(4):371-376. doi:10.1080/03650346909413005.
Hoermann, G. (1997): SIMPEL - ein einfaches, benutzerfreundliches Bodenwassermodell zum Einsatz in der Ausbildung. Deutsche Gewässerkundliche Mitteilungen 41(2):67-72. PDF (unpublished english translation).

Author: O.Conrad (c) 2020
Menu: Simulation|Soil Hydrology

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Precipitation	Grid list, input	`P`	[mm]	-
	Potential Evapotranspiration	Grid list, input	`ETP`	[mm]	-
	Leaf Area Index (*)	Grid, input, optional	`LAI`	-	-
	Glugla Coefficient (*)	Grid, input, optional	`GLUGLA`	Empirical parameter [mm/day], depends on soil texture and structure.	-
	Field Capacity (*)	Grid list, input, optional	`FC`	[vol.%]	-
	Permanent Wilting Point (*)	Grid list, input, optional	`PWP`	[vol.%]	-
	Maxmimum Evapotranspiration (*)	Grid list, input, optional	`ETMAX`	[vol.%/day]	-
Output	Soil Water Content	Grid list, output	`SOIL_WATER`	[mm]	-
	Litter Water Content	Grid, output	`LITTER`	[mm]	-
	Recharge (*)	Grid, output, optional	`RECHARGE`	[mm]	-
	Recharge Sum (*)	Grid, output, optional	`RECHARGE_SUM`	[mm]	-
Options	Grid System	Grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Grid system	Grid system	`LAI_GRIDSYSTEM`	-	-
	Default	Floating point	`LAI_DEFAULT`	default value if no grid has been selected	Minimum: 0.000000 Default: 0.000000
	Grid system	Grid system	`GLUGLA_GRIDSYSTEM`	-	-
	Default	Floating point	`GLUGLA_DEFAULT`	default value if no grid has been selected	Minimum: 0.000000 Default: 150.000000
	Interception Capacity	Floating point	`I_MAX`	Leaf interception capacity [mm] at maximum LAI.	Minimum: 0.000000 Default: 0.000000
	Minimum LAI	Floating point	`LAI_MIN`	Minimum leaf area index.	Minimum: 0.000000 Default: 0.100000
	Maximum LAI	Floating point	`LAI_MAX`	Maximum leaf area index.	Minimum: 0.000000 Default: 4.000000
	Litter Capacity	Floating point	`LITTER_MAX`	[mm]	Minimum: 0.000000 Default: 0.000000
	Litter Drying Factor	Floating point	`LITTER_CF`	Curvature factor determining the drying of the litter storage.	Minimum: 0.000000 Default: 3.000000
	Initial Litter Water Content	Floating point	`LITTER_0`	[mm]	Minimum: 0.000000 Default: 0.000000
	Reset	Boolean	`RESET`	-	Default: 1
	Rooting	Boolean	`DO_ROOTING`	-	Default: 0
	Soil Layers	Static table	`SOIL_LAYERS`	Provide a row for each soil layer: depth [cm], field capacity [vol.%], permanent wilting point [vol.%], maximum ET [vol.%/day], rooting [% of total], initial water content [vol.%].	6 Fields: - 1. [8 byte floating point number] Depth - 2. [8 byte floating point number] FC - 3. [8 byte floating point number] PWP - 4. [8 byte floating point number] ETmax - 5. [8 byte floating point number] Rooting - 6. [8 byte floating point number] Water_0
(*) optional

Command-line

Usage: saga_cmd sim_hydrology 11 [-P <str>] [-ETP <str>] [-LAI <str>] [-LAI_DEFAULT <double>] [-GLUGLA <str>] [-GLUGLA_DEFAULT <double>] [-FC <str>] [-PWP <str>] [-ETMAX <str>] [-SOIL_WATER <str>] [-LITTER <str>] [-RECHARGE <str>] [-RECHARGE_SUM <str>] [-I_MAX <double>] [-LAI_MIN <double>] [-LAI_MAX <double>] [-LITTER_MAX <double>] [-LITTER_CF <double>] [-LITTER_0 <double>] [-RESET <str>] [-DO_ROOTING <str>] [-SOIL_LAYERS <str>]
  -P:<str>                	Precipitation
	Grid list, input
  -ETP:<str>              	Potential Evapotranspiration
	Grid list, input
  -LAI:<str>              	Leaf Area Index
	Grid, input, optional
  -LAI_DEFAULT:<double>   	Default
	Floating point
	Minimum: 0.000000
	Default: 0.000000
  -GLUGLA:<str>           	Glugla Coefficient
	Grid, input, optional
  -GLUGLA_DEFAULT:<double>	Default
	Floating point
	Minimum: 0.000000
	Default: 150.000000
  -FC:<str>               	Field Capacity
	Grid list, input, optional
  -PWP:<str>              	Permanent Wilting Point
	Grid list, input, optional
  -ETMAX:<str>            	Maxmimum Evapotranspiration
	Grid list, input, optional
  -SOIL_WATER:<str>       	Soil Water Content
	Grid list, output
  -LITTER:<str>           	Litter Water Content
	Grid, output
  -RECHARGE:<str>         	Recharge
	Grid, output, optional
  -RECHARGE_SUM:<str>     	Recharge Sum
	Grid, output, optional
  -I_MAX:<double>         	Interception Capacity
	Floating point
	Minimum: 0.000000
	Default: 0.000000
  -LAI_MIN:<double>       	Minimum LAI
	Floating point
	Minimum: 0.000000
	Default: 0.100000
  -LAI_MAX:<double>       	Maximum LAI
	Floating point
	Minimum: 0.000000
	Default: 4.000000
  -LITTER_MAX:<double>    	Litter Capacity
	Floating point
	Minimum: 0.000000
	Default: 0.000000
  -LITTER_CF:<double>     	Litter Drying Factor
	Floating point
	Minimum: 0.000000
	Default: 3.000000
  -LITTER_0:<double>      	Initial Litter Water Content
	Floating point
	Minimum: 0.000000
	Default: 0.000000
  -RESET:<str>            	Reset
	Boolean
	Default: 1
  -DO_ROOTING:<str>       	Rooting
	Boolean
	Default: 0
  -SOIL_LAYERS:<str>      	Soil Layers
	Static table
	6 Fields:
	- 1. [8 byte floating point number] Depth
	- 2. [8 byte floating point number] FC
	- 3. [8 byte floating point number] PWP
	- 4. [8 byte floating point number] ETmax
	- 5. [8 byte floating point number] Rooting
	- 6. [8 byte floating point number] Water_0