SAGA 9.4.2 | Tool Library Documentation

MMF-SAGA Soil Erosion Model


Description

Soil erosion modelling with a modified MMF (Morgan-Morgan-Finney) model (Morgan & Duzant 2008).
This tool is called MMF-SAGA because some things have been implemented differently compared to the original publication. The most important are:



A more detailed description of the model, its modifications, and model application is provided by Setiawan (2012), chapter 6.
Currently, a number of additional grid datasets are outputted to facilitate model evaluation. This can be easily changed within the source code.


References:
Morgan, R.P.C. (2001): A simple approach to soil loss prediction: a revised Morgan-Morgan-Finney model. Catena 44: 305-322.

Morgan, R.P.C., Duzant, J.H. (2008): Modified MMF (Morgan-Morgan-Finney) model for evaluating effects of crops and vegetation cover on soil erosion. Earth Surf. Process. Landforms 32: 90-106.

Setiawan, M. A. (2012): Integrated Soil Erosion Management in the upper Serayu Watershed, Wonosobo District, Central Java Province, Indonesia. Dissertation at the Faculty of Geo- and Atmospheric Sciences of the University of Innsbruck, Austria.


Parameters

 NameTypeIdentifierDescriptionConstraints
InputDigital Terrain Modelgrid, inputDTMDTM, digital terrain model [m]-
Slopegrid, inputSS, slope [rad]-
Channel Networkgrid, input, optionalCHANNELChannel network, all other cells NoData-
Permament Interceptiongrid, inputPIPI, permanent interception expressed as the proportion [between 0-1] of rainfall-
Canopy Covergrid, inputCCCC, canopy cover expressed as a portion [between 0-1] of the soil surface protected by vegetation or crop-
Plant Heightgrid, inputPHPH, plant height [m], representing the effective height from which raindrops fall from the crop or vegetation-
Ratio Evapotranspirationgrid, inputEtEoEt/Eo, ratio of actual to potential evapotranspiration-
Ground covergrid, inputGCGC, Ground cover expressed as a portion [between 0-1] of the soil surface protected by vegetation or crop cover on the ground-
Diameter plant elementsgrid, inputDD, Average diameter [m] of the individual plants elements (stem, leaves) at the ground surface-
Number plant elementsgrid, inputNVNV, Number of plant elements per unit area [number/unit area] at the ground surface-
Soil moisture (at FC)grid, inputMSMS, Soil moisture at field capacity [% w/w]-
Bulk density top layergrid, inputBDBD, Bulk density of the top layer [Mg/m3]-
Effective hydrological depthgrid, inputEHDEHD, Effective hydrological depth of the soil [m]-
Sat. lateral permeabilitygrid, inputLPLP, Saturated lateral permeability of the soil [m/day]-
Percentage claysgrid, inputPER_Cc, Percentage clays [%]-
Percentage siltgrid, inputPER_Zz, Percentage silt [%]-
Percentage sandgrid, inputPER_Ss, Percentage sand [%]-
Percentage rock fragmentsgrid, inputSTST, Percentage rock fragments on the soil surface [%]-
Surface roughnessgrid, input, optionalRFRRFR, Surface roughness [cm/m]. In case the surface roughness is not provided as input, v_flow_t is set to 1.0, i.e. natural soil surface roughness is not accounted for.-
Meteorological datatable, input, optionalTAB_METEOMeteorological data for multiple timestep modelling [model step (day); temperature (Celsius); rainfall (mm), rainfall intensity (mm/h); rainfall duration (day); timespan (days)]-
OutputInterflowgrid, output, optionalIFIF-
Mean runoffgrid, outputQQ, estimation of mean runoff [mm]-
Mean soil lossgrid, outputSLSL, estimation of mean soil loss [kg]-
Effective Rainfallgrid, outputRfRf-
Total Kinetic Energygrid, outputKEKE-
Soil moisture storage capacitygrid, outputRcRc-
Transport Capacity Claygrid, outputTCcTCc-
Transport Capacity Siltgrid, outputTCzTCz-
Transport Capacity Sandgrid, outputTCsSLs-
Available Claygrid, outputGcGc-
Available Siltgrid, outputGzGz-
Available Sandgrid, outputGsGs-
Sediment Balance Claygrid, outputSLcSLc-
Sediment Balance Siltgrid, outputSLzSLz-
Sediment Balance Sandgrid, outputSLsSLs-
Transport Condition Claygrid, outputTCONDcSediment Limited [0], Transport Limited (SL = TC) [1], Transport Limited (SL = G) [2]-
Transport Condition Siltgrid, outputTCONDzSediment Limited [0], Transport Limited (SL = TC) [1], Transport Limited (SL = G) [2]-
Transport Condition Sandgrid, outputTCONDsSediment Limited [0], Transport Limited (SL = TC) [1], Transport Limited (SL = G) [2]-
Upslope Flow Widthgrid, outputW_upW_up-
OptionsGrid Systemgrid systemPARAMETERS_GRID_SYSTEM--
Output file pathfile pathOUT_PATHFull path to the directory for the output grids of each model step-
Simulate InterflowbooleanINTERFLOWSimulate interflowDefault: 1
Mean temperaturefloating point numberTT, mean temperature [degree C]Default: 18.000000
Timespan (days)integer numberTIMESPANThe number of days to model.Minimum: 1 Maximum: 365 Default: 30
Rainfallfloating point numberRR, height of precipitation in timespan [mm]Default: 200.000000
Rainfall intensityfloating point numberII, rainfall intensity [mm/h]Default: 20.000000
Rainfall Durationfloating point numberRnRn, number of rain days in timespan [-]Default: 20.000000
Relationship KE - IchoiceKE_I_METHODRelationship between kinetic energy (KE) and rainfall intensity (I)Available Choices: [0] North America east of Rocky Mountains (Wischmeier & Smith 1978) [1] North-western Europe (Marshall & Palmer) [2] Mediterranean-type climates (Zanchi & Torri 1980) [3] Western Mediterranean (Coutinho & Tomas 1995) [4] Tropical climates (Hudson 1965) [5] Eastern Asia (Onaga et al. 1998) [6] Southern hemisphere climates (Rosewell 1986) [7] Bogor, West-Java, Indonesia (McISaac 1990) Default: 0
Flow Depth (actual flow velocity)floating point numberFLOWD_VAThe flow depth used to calculate the actual flow velocity [m] (e.g. 0.005 unchannelled flow, 0.01 shallow rills, 0.25 deeper rills.Minimum: 0.000000 Default: 0.005000
Route Soil along Channel NetworkbooleanCHANNELTRANSPORTRoute soil loss along channel network to outletDefault: 0

Command Line


Usage: saga_cmd sim_erosion 0 [-DTM ] [-S ] [-CHANNEL ] [-PI ] [-CC ] [-PH ] [-EtEo ] [-GC ] [-D ] [-NV ] [-MS ] [-BD ] [-EHD ] [-LP ] [-PER_C ] [-PER_Z ] [-PER_S ] [-ST ] [-RFR ] [-TAB_METEO ] [-OUT_PATH ] [-INTERFLOW ] [-T ] [-TIMESPAN ] [-IF ] [-R ] [-I ] [-Rn ] [-KE_I_METHOD ] [-FLOWD_VA ] [-CHANNELTRANSPORT ] [-Q ] [-SL ] [-Rf ] [-KE ] [-Rc ] [-TCc ] [-TCz ] [-TCs ] [-Gc ] [-Gz ] [-Gs ] [-SLc ] [-SLz ] [-SLs ] [-TCONDc ] [-TCONDz ] [-TCONDs ] [-W_up ]
  -DTM:             	Digital Terrain Model
	grid, input
  -S:               	Slope
	grid, input
  -CHANNEL:         	Channel Network
	grid, input, optional
  -PI:              	Permament Interception
	grid, input
  -CC:              	Canopy Cover
	grid, input
  -PH:              	Plant Height
	grid, input
  -EtEo:            	Ratio Evapotranspiration
	grid, input
  -GC:              	Ground cover
	grid, input
  -D:               	Diameter plant elements
	grid, input
  -NV:              	Number plant elements
	grid, input
  -MS:              	Soil moisture (at FC)
	grid, input
  -BD:              	Bulk density top layer
	grid, input
  -EHD:             	Effective hydrological depth
	grid, input
  -LP:              	Sat. lateral permeability
	grid, input
  -PER_C:           	Percentage clays
	grid, input
  -PER_Z:           	Percentage silt
	grid, input
  -PER_S:           	Percentage sand
	grid, input
  -ST:              	Percentage rock fragments
	grid, input
  -RFR:             	Surface roughness
	grid, input, optional
  -TAB_METEO:       	Meteorological data
	table, input, optional
  -OUT_PATH:        	Output file path
	file path
  -INTERFLOW:       	Simulate Interflow
	boolean
	Default: 1
  -T:            	Mean temperature
	floating point number
	Default: 18.000000
  -TIMESPAN:        	Timespan (days)
	integer number
	Minimum: 1
	Maximum: 365
	Default: 30
  -IF:              	Interflow
	grid, output, optional
  -R:            	Rainfall
	floating point number
	Default: 200.000000
  -I:            	Rainfall intensity
	floating point number
	Default: 20.000000
  -Rn:           	Rainfall Duration
	floating point number
	Default: 20.000000
  -KE_I_METHOD:     	Relationship KE - I
	choice
	Available Choices:
	[0] North America east of Rocky Mountains (Wischmeier & Smith 1978)
	[1] North-western Europe (Marshall & Palmer)
	[2] Mediterranean-type climates (Zanchi & Torri 1980)
	[3] Western Mediterranean (Coutinho & Tomas 1995)
	[4] Tropical climates (Hudson 1965)
	[5] Eastern Asia (Onaga et al. 1998)
	[6] Southern hemisphere climates (Rosewell 1986)
	[7] Bogor, West-Java, Indonesia (McISaac 1990)
	Default: 0
  -FLOWD_VA:     	Flow Depth (actual flow velocity)
	floating point number
	Minimum: 0.000000
	Default: 0.005000
  -CHANNELTRANSPORT:	Route Soil along Channel Network
	boolean
	Default: 0
  -Q:               	Mean runoff
	grid, output
  -SL:              	Mean soil loss
	grid, output
  -Rf:              	Effective Rainfall
	grid, output
  -KE:              	Total Kinetic Energy
	grid, output
  -Rc:              	Soil moisture storage capacity
	grid, output
  -TCc:             	Transport Capacity Clay
	grid, output
  -TCz:             	Transport Capacity Silt
	grid, output
  -TCs:             	Transport Capacity Sand
	grid, output
  -Gc:              	Available Clay
	grid, output
  -Gz:              	Available Silt
	grid, output
  -Gs:              	Available Sand
	grid, output
  -SLc:             	Sediment Balance Clay
	grid, output
  -SLz:             	Sediment Balance Silt
	grid, output
  -SLs:             	Sediment Balance Sand
	grid, output
  -TCONDc:          	Transport Condition Clay
	grid, output
  -TCONDz:          	Transport Condition Silt
	grid, output
  -TCONDs:          	Transport Condition Sand
	grid, output
  -W_up:            	Upslope Flow Width
	grid, output