Module MMF-SAGA Soil Erosion Model
Soil erosion modelling with a modified MMF (Morgan-Morgan-Finney) model (Morgan & Duzant 2008).
This module is called MMF-SAGA because some things have been implemented differently compared to the original publication. The most important are:
- the extension of the model to support spatially distributed modelling
- the introduction of a "Channel Network" layer
- the introduction of a "rainfall duration" (time span) parameter
- the exposure of the flow depth parameter
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.
- Author: (c) 2009-2012 V. Wichmann, M. Setiawan
- Specification: grid
- Menu: Simulation|Erosion
Parameters
Name | Type | Identifier | Description | Constraints | |
---|---|---|---|---|---|
Input | Digital Terrain Model | Grid (input) | DTM | DTM, digital terrain model [m] | - |
Slope | Grid (input) | S | S, slope [rad] | - | |
Channel Network (*) | Grid (optional input) | CHANNEL | Channel network, all other cells NoData | - | |
Permament Interception | Grid (input) | PI | PI, permanent interception expressed as the proportion [between 0-1] of rainfall | - | |
Canopy Cover | Grid (input) | CC | CC, canopy cover expressed as a portion [between 0-1] of the soil surface protected by vegetation or crop | - | |
Plant Height | Grid (input) | PH | PH, plant height [m], representing the effective height from which raindrops fall from the crop or vegetation | - | |
Ratio Evapotranspiration | Grid (input) | EtEo | Et/Eo, ratio of actual to potential evapotranspiration | - | |
Ground cover | Grid (input) | GC | GC, Ground cover expressed as a portion [between 0-1] of the soil surface protected by vegetation or crop cover on the ground | - | |
Diameter plant elements | Grid (input) | D | D, Average diameter [m] of the individual plants elements (stem, leaves) at the ground surface | - | |
Number plant elements | Grid (input) | NV | NV, Number of plant elements per unit area [number/unit area] at the ground surface | - | |
Soil moisture (at FC) | Grid (input) | MS | MS, Soil moisture at field capacity [% w/w] | - | |
Bulk density top layer | Grid (input) | BD | BD, Bulk density of the top layer [Mg/m3] | - | |
Effective hydrological depth | Grid (input) | EHD | EHD, Effective hydrological depth of the soil [m] | - | |
Sat. lateral permeability | Grid (input) | LP | LP, Saturated lateral permeability of the soil [m/day] | - | |
Percentage clays | Grid (input) | PER_C | c, Percentage clays [%] | - | |
Percentage silt | Grid (input) | PER_Z | z, Percentage silt [%] | - | |
Percentage sand | Grid (input) | PER_S | s, Percentage sand [%] | - | |
Percentage rock fragments | Grid (input) | ST | ST, Percentage rock fragments on the soil surface [%] | - | |
Surface roughness | Grid (input) | RFR | RFR, Surface roughness [cm/m] | - | |
Meteorological data (*) | Table (optional input) | TAB_METEO | Meteorological data for multiple timestep modelling [model step (day); temperature (Celsius); rainfall (mm), rainfall intensity (mm/h); rainfall duration (day); timespan (days)] | - | |
Output | Interflow (*) | Grid (optional output) | IF | IF | - |
Mean runoff | Grid (output) | Q | Q, estimation of mean runoff [mm] | - | |
Mean soil loss | Grid (output) | SL | SL, estimation of mean soil loss [kg] | - | |
Effective Rainfall | Grid (output) | Rf | Rf | - | |
Total Kinetic Energy | Grid (output) | KE | KE | - | |
Soil moisture storage capacity | Grid (output) | Rc | Rc | - | |
Transport Capacity Clay | Grid (output) | TCc | TCc | - | |
Transport Capacity Silt | Grid (output) | TCz | TCz | - | |
Transport Capacity Sand | Grid (output) | TCs | SLs | - | |
Available Clay | Grid (output) | Gc | Gc | - | |
Available Silt | Grid (output) | Gz | Gz | - | |
Available Sand | Grid (output) | Gs | Gs | - | |
Sediment Balance Clay | Grid (output) | SLc | SLc | - | |
Sediment Balance Silt | Grid (output) | SLz | SLz | - | |
Sediment Balance Sand | Grid (output) | SLs | SLs | - | |
Transport Condition Clay | Grid (output) | TCONDc | Sediment Limited [0], Transport Limited (SL = TC) [1], Transport Limited (SL = G) [2] | - | |
Transport Condition Silt | Grid (output) | TCONDz | Sediment Limited [0], Transport Limited (SL = TC) [1], Transport Limited (SL = G) [2] | - | |
Transport Condition Sand | Grid (output) | TCONDs | Sediment Limited [0], Transport Limited (SL = TC) [1], Transport Limited (SL = G) [2] | - | |
Upslope Flow Width | Grid (output) | W_up | W_up | - | |
Options | Output file path | File path | OUT_PATH | Full path to the directory for the output grids of each model step | - |
Simulate Interflow | Boolean | INTERFLOW | Simulate interflow | Default: 1 | |
Mean temperature | Floating point | T | T, mean temperature [degree C] | Default: 18.000000 | |
Timespan (days) | Integer | TIMESPAN | The number of days to model. | Minimum: 1 Maximum: 365 Default: 30 | |
Rainfall | Floating point | R | R, height of precipitation in timespan [mm] | Default: 200.000000 | |
Rainfall intensity | Floating point | I | I, rainfall intensity [mm/h] | Default: 20.000000 | |
Rainfall Duration | Floating point | Rn | Rn, number of rain days in timespan [-] | Default: 20.000000 | |
Relationship KE - I | Choice | KE_I_METHOD | Relationship 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 | FLOWD_VA | The 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 Network | Boolean | CHANNELTRANSPORT | Route soil loss along channel network to outlet | Default: 0 | |
(*) optional |
Command-line
Usage: saga_cmd sim_erosion 0 -DTM <str> -S <str> [-CHANNEL <str>] -PI <str> -CC <str> -PH <str> -EtEo <str> -GC <str> -D <str> -NV <str> -MS <str> -BD <str> -EHD <str> -LP <str> -PER_C <str> -PER_Z <str> -PER_S <str> -ST <str> -RFR <str> [-TAB_METEO <str>] [-OUT_PATH <str>] [-INTERFLOW <str>] [-T <str>] [-TIMESPAN <num>] [-IF <str>] [-R <str>] [-I <str>] [-Rn <str>] [-KE_I_METHOD <str>] [-FLOWD_VA <str>] [-CHANNELTRANSPORT <str>] [-Q <str>] [-SL <str>] [-Rf <str>] [-KE <str>] [-Rc <str>] [-TCc <str>] [-TCz <str>] [-TCs <str>] [-Gc <str>] [-Gz <str>] [-Gs <str>] [-SLc <str>] [-SLz <str>] [-SLs <str>] [-TCONDc <str>] [-TCONDz <str>] [-TCONDs <str>] [-W_up <str>] -DTM:<str> Digital Terrain Model Grid (input) -S:<str> Slope Grid (input) -CHANNEL:<str> Channel Network Grid (optional input) -PI:<str> Permament Interception Grid (input) -CC:<str> Canopy Cover Grid (input) -PH:<str> Plant Height Grid (input) -EtEo:<str> Ratio Evapotranspiration Grid (input) -GC:<str> Ground cover Grid (input) -D:<str> Diameter plant elements Grid (input) -NV:<str> Number plant elements Grid (input) -MS:<str> Soil moisture (at FC) Grid (input) -BD:<str> Bulk density top layer Grid (input) -EHD:<str> Effective hydrological depth Grid (input) -LP:<str> Sat. lateral permeability Grid (input) -PER_C:<str> Percentage clays Grid (input) -PER_Z:<str> Percentage silt Grid (input) -PER_S:<str> Percentage sand Grid (input) -ST:<str> Percentage rock fragments Grid (input) -RFR:<str> Surface roughness Grid (input) -TAB_METEO:<str> Meteorological data Table (optional input) -OUT_PATH:<str> Output file path File path -INTERFLOW:<str> Simulate Interflow Boolean Default: 1 -T:<str> Mean temperature Floating point Default: 18.000000 -TIMESPAN:<num> Timespan (days) Integer Minimum: 1 Maximum: 365 Default: 30 -IF:<str> Interflow Grid (optional output) -R:<str> Rainfall Floating point Default: 200.000000 -I:<str> Rainfall intensity Floating point Default: 20.000000 -Rn:<str> Rainfall Duration Floating point Default: 20.000000 -KE_I_METHOD:<str> 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:<str> Flow Depth (actual flow velocity) Floating point Minimum: 0.000000 Default: 0.005000 -CHANNELTRANSPORT:<str> Route Soil along Channel Network Boolean Default: 0 -Q:<str> Mean runoff Grid (output) -SL:<str> Mean soil loss Grid (output) -Rf:<str> Effective Rainfall Grid (output) -KE:<str> Total Kinetic Energy Grid (output) -Rc:<str> Soil moisture storage capacity Grid (output) -TCc:<str> Transport Capacity Clay Grid (output) -TCz:<str> Transport Capacity Silt Grid (output) -TCs:<str> Transport Capacity Sand Grid (output) -Gc:<str> Available Clay Grid (output) -Gz:<str> Available Silt Grid (output) -Gs:<str> Available Sand Grid (output) -SLc:<str> Sediment Balance Clay Grid (output) -SLz:<str> Sediment Balance Silt Grid (output) -SLs:<str> Sediment Balance Sand Grid (output) -TCONDc:<str> Transport Condition Clay Grid (output) -TCONDz:<str> Transport Condition Silt Grid (output) -TCONDs:<str> Transport Condition Sand Grid (output) -W_up:<str> Upslope Flow Width Grid (output)