unifhycontrib.gr4

class unifhycontrib.gr4.SubSurfaceComponent

The GR4 (“Génie Rural à 4 paramètres” [in French]) model is a bucket-type rainfall-runoff model featuring four parameters.

It is typically used as a daily model, i.e. GR4J model (Perrin et al., 2003). It can also be used at other temporal resolutions, e.g. hourly in GR4H model, provided an adjustment in its time-dependent parameter and constant values is performed (Ficchì et al., 2016). The model has recently been expressed in a state-space formulation (Santos et al., 2018).

This version of the GR4 model is based on its explicit state-space formulation and its recommended temporal resolutions are daily or hourly. With either of these resolutions, time-dependent parameters x2, x3, x4, and constant nu are expected for the daily case and they are adjusted accordingly if temporal resolution is not daily.

The subsurface component of the GR4 model comprises the runoff generation and the runoff routing using the Nash cascade.

Contributors

Thibault Hallouin [1,2]

Affiliations

Department of Meteorology, University of Reading
National Centre for Atmospheric Science

Licence

GPL-2.0

Codebase

https://github.com/unifhy-org/unifhycontrib-gr4

Inwards

name: canopy_liquid_throughfall_and_snow_melt_flux
units: kg m^-2 s^-1
from: surfacelayer
method: mean

name: transpiration_flux_from_root_uptake
units: kg m^-2 s^-1
from: surfacelayer
method: mean

Outwards

name: soil_water_stress_for_transpiration
units: 1
to: surfacelayer
method: mean

name: surface_runoff_flux_delivered_to_rivers
units: kg m^-2 s^-1
to: openwater
method: mean

Parameters

name: x1
units: kg m^-2

name: x4
units: d

Constants

name: alpha
description: production precipitation exponent
units: 1
default_value: 2.0e+00

name: beta
description: percolation exponent
units: 1
default_value: 5.0e+00

name: nu
description: percolation coefficient
units: 1
default_value: 4.444444444444444e-01

name: nres
description: number of stores in Nash cascade
units: 1
default_value: 1.1e+01

States

name: production_store
units: kg m^-2

name: nash_cascade_stores
description: stores in Nash cascade
units: kg m^-2
divisions: nres

SpaceDomain Properties

name: land_sea_mask
required: False

name: flow_direction
required: False

name: cell_area
required: False