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NAME
r.sim.terrain - Dynamic landscape evolution model
KEYWORDS
raster,
terrain,
landscape,
evolution,
parallel
SYNOPSIS
r.sim.terrain
r.sim.terrain --help
r.sim.terrain [-f] elevation=name runs=string mode=string [rain_intensity=integer] [rain_duration=integer] [precipitation=name] [k_factor=name] [k_factor_value=float] [c_factor=name] [c_factor_value=float] [m=float] [n=float] [walkers=integer] [runoff=name] [runoff_value=float] [mannings=name] [mannings_value=float] [detachment=name] [detachment_value=float] [transport=name] [transport_value=float] [shearstress=name] [shearstress_value=float] [density=name] [density_value=float] [mass=name] [mass_value=float] [grav_diffusion=float] [erdepmin=float] [erdepmax=float] start=string rain_interval=integer temporaltype=name [threads=integer] elevation_timeseries=name [depth_timeseries=name] [erdep_timeseries=name] [flux_timeseries=name] [difference_timeseries=name] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -f
- Fill depressions
- --overwrite
- Allow output files to overwrite existing files
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- elevation=name [required]
- Name of input elevation raster map
- runs=string [required]
- Run for a single rainfall event or a series of events
- Options: event, series
- Default: event
- event: single rainfall event
- series: series of rainfall events
- mode=string [required]
- SIMWE erosion deposition, USPED transport limited, or RUSLE 3D detachment limited mode
- Options: simwe_mode, usped_mode, rusle_mode
- Default: simwe_mode
- simwe_mode: SIMWE erosion deposition mode
- usped_mode: USPED transport limited mode
- rusle_mode: RUSLE 3D detachment limited mode
- rain_intensity=integer
- Rainfall intensity in mm/hr
- Default: 50
- rain_duration=integer
- Total duration of storm event in minutes
- Default: 60
- precipitation=name
- Precipitation file
- Name of input precipitation file
- k_factor=name
- K factor
- Soil erodibility factor
- k_factor_value=float
- K factor constant
- Soil erodibility constant
- Default: 0.25
- c_factor=name
- C factor
- Land cover factor
- c_factor_value=float
- C factor constant
- Land cover constant
- Default: 0.1
- m=float
- Water flow exponent
- Water flow exponent
- Default: 1.5
- n=float
- Slope exponent
- Slope exponent
- Default: 1.2
- walkers=integer
- Number of walkers (max = 7000000)
- Default: 1000000
- runoff=name
- Runoff coefficient
- Runoff coefficient (0.6 for bare earth, 0.35 for grass or crops, 0.5 for shrubs and trees, 0.25 for forest, 0.95 for roads)
- runoff_value=float
- Runoff coefficient
- Runoff coefficient (0.6 for bare earth, 0.35 for grass or crops, 0.5 for shrubs and trees, 0.25 for forest, 0.95 for roads)
- Default: 0.35
- mannings=name
- Manning's roughness coefficient
- Manning's roughness coefficient
- mannings_value=float
- Manning's roughness coefficient
- Manning's roughness coefficient
- Default: 0.04
- detachment=name
- Detachment coefficient
- Detachment coefficient
- detachment_value=float
- Detachment coefficient
- Detachment coefficient
- Default: 0.01
- transport=name
- Transport coefficient
- Transport coefficient
- transport_value=float
- Transport coefficient
- Transport coefficient
- Default: 0.01
- shearstress=name
- Shear stress coefficient
- Shear stress coefficient
- shearstress_value=float
- Shear stress coefficient
- Shear stress coefficient
- Default: 0.0
- density=name
- Sediment mass density
- Sediment mass density in g/cm^3
- density_value=float
- Sediment mass density
- Sediment mass density in g/cm^3
- Default: 1.4
- mass=name
- Mass of sediment per unit area
- Mass of sediment per unit area in kg/m^2
- mass_value=float
- Mass of sediment per unit area
- Mass of sediment per unit area in kg/m^2
- Default: 116.
- grav_diffusion=float
- Gravitational diffusion coefficient
- Gravitational diffusion coefficient in m^2/s
- Default: 0.1
- erdepmin=float
- Minimum values for erosion-deposition
- Minimum values for erosion-deposition in kg/m^2s
- Default: -0.5
- erdepmax=float
- Maximum values for erosion-deposition
- Maximum values for erosion-deposition in kg/m^2s
- Default: 0.5
- start=string [required]
- Start time in year-month-day hour:minute:second format
- Default: 2016-01-01 00:00:00
- rain_interval=integer [required]
- Time interval between evolution events in minutes
- Default: 1
- temporaltype=name [required]
- The temporal type of the space time dataset
- Options: absolute, relative
- Default: absolute
- threads=integer
- Number of threads for multiprocessing
- Default: 1
- elevation_timeseries=name [required]
- Name of the output space time raster dataset
- Default: elevation_timeseries
- depth_timeseries=name
- Name of the output space time raster dataset
- Default: depth_timeseries
- erdep_timeseries=name
- Name of the output space time raster dataset
- Default: erdep_timeseries
- flux_timeseries=name
- Name of the output space time raster dataset
- Default: flux_timeseries
- difference_timeseries=name
- Name of the output space time raster dataset
- Default: difference_timeseries
r.sim.terrain is a short-term landscape evolution model
that simulates topographic change
for both steady state and dynamic flow regimes
across a range of spatial scales.
It uses empirical models (RUSLE3D & USPED)
for soil erosion at watershed to regional scales
and a physics-based model (SIMWE)
for shallow overland water flow and soil erosion
at subwatershed scales
to compute short-term topographic change.
This either steady state or dynamic model simulates
how overland sediment mass flows reshape topography
for a range of hydrologic soil erosion regimes
based on topographic, land cover, soil, and rainfall parameters.
Basic instructions
A basic example for the
North Carolina sample dataset.
Install the add-on module
r.sim.terrain.
Copy the raster elevation map
elev_lid792_1m from the PERMANENT mapset
to the current mapset.
Set the region to this elevation map at 1 meter resolution.
Run
r.sim.terrain with the RUSLE model
for a 120 min event with a rainfall intensity of 50 mm/hr
at a 3 minute interval.
Set the empirical coefficients m and n to 0.4 and 1.3 respectively.
Use the `-f` flag to fill depressions
in order to reduce the effect of positive feedback loops.
g.extension extension=r.sim.terrain
g.copy raster=elev_lid792_1m@PERMANENT,elevation
g.region raster=elev_lid792_1m res=1
r.sim.terrain -f elevation=elevation runs=event mode=rusle_mode rain_intensity=50.0 rain_duration=120 rain_interval=3 m=0.4 n=1.3
Figure: Net difference (m) for a dynamic RUSLE simulation
of a 120 min event with a rainfall intensity of 50 mm/hr with a 3 minute interval.
Spatially variable soil and landcover
Clone or download the
landscape evolution sample dataset
with a time series of lidar-based digital elevation models and orthoimagery
for a highly eroded subwatershed of Patterson Branch Creek,
Fort Bragg, NC, USA.
Run r.sim.terrain with the simwe model
for a 120 min event with a rainfall intensity of 50 mm/hr.
Use a transport value lower than the detachment value
to trigger a transport limited erosion regime.
Use the -f flag to fill depressions
in order to reduce the effect of positive feedback loops.
g.mapset -c mapset=transport location=nc_spm_evolution
g.region region=region res=1
r.mask vector=watershed
g.copy raster=elevation_2016@PERMANENT,elevation_2016
r.sim.terrain -f elevation=elevation_2016 runs=event mode=simwe_mode \
rain_intensity=50.0 rain_interval=120 rain_duration=10 walkers=1000000 \
detachment_value=0.01 transport_value=0.0001 manning=mannings runoff=runoff
Figure: Net difference (m)
for a steady state, transport limited SIMWE simulation
of a 120 min event with a rainfall intensity of 50 mm/hr.
For more detailed instructions and examples see this in-depth
tutorial.
If the module fails with
ERROR: Unable to insert dataset of type raster in the temporal database. The mapset of the dataset does not match the current mapset.
check that the input
elevation map is in the current mapset.
The input
elevation map must be in the current mapset
so that it can be registered in the temporal database.
-
Harmon, B. A., Mitasova, H., Petrasova, A., and Petras, V.: r.sim.terrain 1.0: a landscape evolution model with dynamic hydrology, Geosci. Model Dev., 12, 2837–2854, https://doi.org/10.5194/gmd-12-2837-2019, 2019.
-
Mitasova H., Barton M., Ullah I., Hofierka J., Harmon R.S., 2013.
3.9 GIS-Based Soil Erosion Modeling.
In J. F. Shroder, ed. Treatise on Geomorphology. San Diego: Academic Press, pp. 228-258.
DOI: https://doi.org/10.1016/B978-0-12-374739-6.00052-X.
r.sim.water,
r.sim.sediment
Brendan A. Harmon
Louisiana State University
brendan.harmon@gmail.com
SOURCE CODE
Available at:
r.sim.terrain source code
(history)
Latest change: Monday Nov 11 18:04:48 2024 in commit: 59e289fdb093de6dd98d5827973e41128196887d
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GRASS Development Team,
GRASS GIS 8.3.3dev Reference Manual