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
  1. Department of Meteorology, University of Reading

  2. 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