Tool MMF-SAGA Soil Erosion Model
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:
- 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
- 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, input, optional | 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, optional | RFR | RFR, 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 data (*) | Table, input, optional | 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, output, optional | 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 | Grid System | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
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 <double>] [-TIMESPAN <num>] [-IF <str>] [-R <double>] [-I <double>] [-Rn <double>] [-KE_I_METHOD <str>] [-FLOWD_VA <double>] [-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, input, optional -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, optional -TAB_METEO:<str> Meteorological data Table, input, optional -OUT_PATH:<str> Output file path File path -INTERFLOW:<str> Simulate Interflow Boolean Default: 1 -T:<double> Mean temperature Floating point Default: 18.000000 -TIMESPAN:<num> Timespan (days) Integer Minimum: 1 Maximum: 365 Default: 30 -IF:<str> Interflow Grid, output, optional -R:<double> Rainfall Floating point Default: 200.000000 -I:<double> Rainfall intensity Floating point Default: 20.000000 -Rn:<double> 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:<double> 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