Computing inputs to FLUSH 3D soil model to study hydrology of drained peatland forest. (Stenberg et al. 2018, Hydrology of Drained Peatland Forest: Numerical Experiment on the Role of Tree Stand Heterogeneity and Management, https://www.mdpi.com/1999-4907/9/10/645)
The repository contains Python-codes, ini-files and input/output datafiles used to produce input data to FLUSH 3D soil model at Sattasuo drained peatland forest.
Satta_main.py is the main code, calls run_model from canopymodel.py. run_model.py is driver for canopy interception and evapotranspiration model CanopyGrid. The class is modified version of SpatHy -code.
Inputs: daily weather data (Precip, Tair, Rglob, VPD) & parameters defined in sattasuo.ini
- doy
- Prec - mm d-1
- Rg - global radiation Wm-2
- T, Tmax, Tmin - degC mean, max and minimum daily temperature
- VPD - kPa vapor pressure deficit
Calculates:
- interception of rain & snow in overstory canopy
- throughfall rate to understory layer
- virtual snowpack (snow water equivalent SWE, mm) evolution at forest floor
- interception of rain or meltwater at field/bottomlayer
- potential infiltration to soil
- evaporation from free water storages (canopy & field/bottom layer) is basen on Priestley-Taylor equilibrium evaporation; attenuation of radiation in canopy is exponential
- Transpiration from over- and understory layers (Tr_o, Tr_u, mmd-1) is computed assuming well-coupled conditions:
Tr_i = C x Gi x VPD / P,
where Gi is layer's integrated conductance (ms-1), VPD vapor pressure deficit (kPa) and P (kPa) ambient pressure. C = Cair * Mwater is conversion factor from ms-1 to kgm-2s-1.
The Gi is slight simplification on Launiainen et al. (2018) GMDD, modified from Saugier & Katerji, 1991 and Kelliher et al. 1995.
Gi = gsref * fQ * fVPD * fPheno * fRew
gsref = leaf stomatal conductance at 1kPa and saturated light (ms-1) fQ = light modifier, fVPD = vpd modifier, fPheno = phenology modifier, fRew = soil water modifier (here fRew = 1 since FLUSH accounts for restriction)
Returns:
- PotInf - mm d-1 potential infiltration rate to soil (i.e. throughfall below living moss layer)
- Tr_o - mm d-1 overstory transpiration rate
- Tr_u - mm d-1 understory transpiration rate
- Trfall - mm d-1 throughfall rate below overstory (comparison for measurements)
- Interc_o - mm d-1 interception rate overstory
- Interc_u - mm d-1 interception rate understory
- Evap_o - mm d-1 evaporation rate from ovestory storage
- Evap_u - mm d-1 evaporation rate from understory storage
- ET - mm d-1 total ET
- SWE - mm snow water equivalent