:pycom3Hybrid
is a computational module that combines the dense flow avalanche (DFA) simulation model (com1DFA) and the Alpha-Beta statistical one (com2AB), taking advantage of their strength and trying to reduce their weaknesses. The weakness of the DFA simulation lies in its required inputs, among which is the friction parameter μ. The disadvantage of the statistical model lies in the necessary path, which is used to extract an avalanche profile and compute a runout angle. The idea here is to determine the avalanche path in an automated way by:
- first, running a DFA simulation
- computing a mass averaged path from the results
- use the path to compute the runout angle corresponding to this specific avalanche
- using a coulomb friction method, the friction parameter μ is extracted from the runout
- the resulting μ is used in the input for a new DFA simulation.
This iteration process can be repeated multiple times until "convergence", which means until the μ or α value stops varying.
- raster of the DEM (.asc file)
- a release feature (shapefile) in
Inputs/REL
- Split point (shapefile). This requirement is planned to be automated as well.
- The avalanche path specific for the input topography
- the μ value (α travel angle) specific for the input topography
- results from the DFA simulation for the input topography
- a combined plot showing the results of the DFA simulation and Alpha-Beta model
- go to
AvaFrame/avaframe
- copy
com3Hybrid/com3HybridCfg.ini
tocom3Hybrid/local_com3HybridCfg.ini
and edit (if not, default values are used) - put your com1DFA and com2AB settings in
com3Hybrid/hybridModel_com1DFACfg.ini
andcom3Hybrid/hybridModel_com2ABCfg.ini
(these files replace the local.ini
files incom1DFA
andcom2AB
) - make sure all the required inputs are available in the avalanche directory
- enter the path to the desired dataset in
local_avaframeCfg.ini
run:
python3 runScripts/runCom3Hybrid.py
- A first com1DFA simulation is run using the
com3Hybrid/hybridModel_com1DFACfg.ini
configuration and the μ provided incom3Hybrid/local_com3HybridCfg.ini
. - The mass averaged path is computed from the DFA simulation using the :py
ana5Utils.DFAPathGeneration
. From this we obtain the (x,y,z) and (s,z) coordinates of the avalanche profile (the path is extended towards the relase and in the runout). This path is saved toavalancheDir/Inputs/LINES
and replaces the old path. A copy is also saved toavalancheDir/Outputs/com3Hybrid
. - com2AB module is run using the
com3Hybrid/hybridModel_com2ABCfg.ini
to compute the μ = tan α friction parameter corresponding to this specific avalanche and area. - The
com3Hybrid/hybridModel_com1DFACfg.ini
is updated with the new μ = tan α value and com1DFA simulation is run again. - Steps 2. and 3. are repeated to get the new avalanche path and μ = tan α value.
This process is repeated as long as the α = arctan μ value varies from more than alphaThreshold
which you can specify in com3Hybrid/local_com3HybridCfg.ini
(this is a value in degrees) and this for a maximum of nIterMax
iterations.
The parameters for path generation (section PATH
of com3Hybrid/local_com3HybridCfg.ini
) are described in moduleAna5Utils:Automated path generation
.
The parameters for the DFA simulation are to be specified in com3Hybrid/hybridModel_com1DFACfg.ini
. This file replaces the local_com1DFACfg.ini
that is usually used to run a com1DFA simulation.
The parameters for the α − β model are to be specified in com3Hybrid/hybridModel_com2ABCfg.ini
. This file replaces the local_com2ABCfg.ini
that is usually used to run a com2AB simulation.