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:
| | 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 (optional input) | 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 (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 | Grid system | Grid system | PARAMETERS_GRID_SYSTEM | 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 |