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i.evapo.zk

Computes global evapotranspiration calculation after Zhang, Kimball, Nemani and Running formulation, 2010.

i.evapo.zk biome_type=name ndvi=name airtemperature=name specifichumidity=name atmosphericpressure=name netradiation=name soilheatflux=name elevation=name output=name [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

i.evapo.zk biome_type=name ndvi=name airtemperature=name specifichumidity=name atmosphericpressure=name netradiation=name soilheatflux=name elevation=name output=name

grass.script.run_command("i.evapo.zk", biome_type, ndvi, airtemperature, specifichumidity, atmosphericpressure, netradiation, soilheatflux, elevation, output, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

gs.run_command("i.evapo.zk", biome_type="name", ndvi="name", airtemperature="name", specifichumidity="name", atmosphericpressure="name", netradiation="name", soilheatflux="name", elevation="name", output="name")

grass.tools.Tools.i_evapo_zk(biome_type, ndvi, airtemperature, specifichumidity, atmosphericpressure, netradiation, soilheatflux, elevation, output, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

tools = Tools()
tools.i_evapo_zk(biome_type="name", ndvi="name", airtemperature="name", specifichumidity="name", atmosphericpressure="name", netradiation="name", soilheatflux="name", elevation="name", output="name")

This grass.tools API is experimental in version 8.5 and expected to be stable in version 8.6.

Parameters

biome_type=name [required]
    Name of input IGBP biome type raster map [-]
ndvi=name [required]
    Name of input Normalized Difference Vegetation Index raster map [-]
airtemperature=name [required]
    Name of input air temperature raster map [C]
specifichumidity=name [required]
    Name of input specific humidity raster map [-]
atmosphericpressure=name [required]
    Name of input atmospheric pressure raster map [Pa]
netradiation=name [required]
    Name of input net radiation raster map [MJ/m2/d]
soilheatflux=name [required]
    Name of input soil heat flux raster map [MJ/m2/d]
elevation=name [required]
    Name of input elevation raster map [m]
output=name [required]
    Name of output evapotranspiration raster map [mm/d]
--overwrite
    Allow output files to overwrite existing files
--help
    Print usage summary
--verbose
    Verbose module output
--quiet
    Quiet module output
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

biome_type : str, required
    Name of input IGBP biome type raster map [-]
    Used as: input, raster, name
ndvi : str, required
    Name of input Normalized Difference Vegetation Index raster map [-]
    Used as: input, raster, name
airtemperature : str, required
    Name of input air temperature raster map [C]
    Used as: input, raster, name
specifichumidity : str, required
    Name of input specific humidity raster map [-]
    Used as: input, raster, name
atmosphericpressure : str, required
    Name of input atmospheric pressure raster map [Pa]
    Used as: input, raster, name
netradiation : str, required
    Name of input net radiation raster map [MJ/m2/d]
    Used as: input, raster, name
soilheatflux : str, required
    Name of input soil heat flux raster map [MJ/m2/d]
    Used as: input, raster, name
elevation : str, required
    Name of input elevation raster map [m]
    Used as: input, raster, name
output : str, required
    Name of output evapotranspiration raster map [mm/d]
    Used as: output, raster, name
overwrite : bool, optional
    Allow output files to overwrite existing files
    Default: None
verbose : bool, optional
    Verbose module output
    Default: None
quiet : bool, optional
    Quiet module output
    Default: None
superquiet : bool, optional
    Very quiet module output
    Default: None

biome_type : str | np.ndarray, required
    Name of input IGBP biome type raster map [-]
    Used as: input, raster, name
ndvi : str | np.ndarray, required
    Name of input Normalized Difference Vegetation Index raster map [-]
    Used as: input, raster, name
airtemperature : str | np.ndarray, required
    Name of input air temperature raster map [C]
    Used as: input, raster, name
specifichumidity : str | np.ndarray, required
    Name of input specific humidity raster map [-]
    Used as: input, raster, name
atmosphericpressure : str | np.ndarray, required
    Name of input atmospheric pressure raster map [Pa]
    Used as: input, raster, name
netradiation : str | np.ndarray, required
    Name of input net radiation raster map [MJ/m2/d]
    Used as: input, raster, name
soilheatflux : str | np.ndarray, required
    Name of input soil heat flux raster map [MJ/m2/d]
    Used as: input, raster, name
elevation : str | np.ndarray, required
    Name of input elevation raster map [m]
    Used as: input, raster, name
output : str | type(np.ndarray) | type(np.array) | type(gs.array.array), required
    Name of output evapotranspiration raster map [mm/d]
    Used as: output, raster, name
overwrite : bool, optional
    Allow output files to overwrite existing files
    Default: None
verbose : bool, optional
    Verbose module output
    Default: None
quiet : bool, optional
    Quiet module output
    Default: None
superquiet : bool, optional
    Very quiet module output
    Default: None

Returns:

result : grass.tools.support.ToolResult | np.ndarray | tuple[np.ndarray] | None
If the tool produces text as standard output, a ToolResult object will be returned. Otherwise, None will be returned. If an array type (e.g., np.ndarray) is used for one of the raster outputs, the result will be an array and will have the shape corresponding to the computational region. If an array type is used for more than one raster output, the result will be a tuple of arrays.

DESCRIPTION

i.evapo.zk Calculates the global diurnal evapotranspiration after Zhang, Kimball, Nemani and Running (2010).

NOTES

Main function ETa (biome_type, ndvi, tday, sh, patm, Rn, G)

  • Biome_type as defined below
  • ndvi NDVI value [-]
  • tday day temperature [C]
  • sh specific humidity [-]
  • patm atmospheric pressure [Pa]
  • Rn day net radiation [MJ/m2/d]
  • G day soil heat flux [MJ/m2/d]

IGBP Biome types with ID used in this model:

  • Code ID Description
  • BENF 0 Boreal Evergreen Needleleaf Forest (less or eq 212 frost-free days)
  • TENF 1 Temperate Evergreen Needleleaf Forest (more than 212 frost-free days)
  • EBF 2 Evergreen Broadleaf Forest
  • DBF 4 Deciduous Broadleaf Forest
  • CSH 6 Closed Shrubland
  • OSH 7 Open Shrubland
  • WSV 8 Woody Savannah
  • SV 9 Savannah
  • GRS 10 Grassland
  • CRP 12 Cropland

IGBP Classification:

  • 01 Evergreen Needleleaf Forest
  • 02 Evergreen Broadleaf Forest
  • 03* Deciduous Needleleaf Forest
  • 04 Deciduous Broadleaf Forest
  • 05* Mixed Forest (stats of other classes areas used in article)
  • 06 Closed Shrublands
  • 07 Open Shrublands
  • 08 Woody Savannas
  • 09 Savannas
  • 10 Grasslands
  • 11* Permanent Wetlands
  • 12 Croplands
  • 13* Urban and Built-Up
  • 14* Cropland/Natural Vegetation Mosaic
  • 15* Snow and Ice
  • 16* Barren or Sparsely Vegetated
  • 17* Water Bodies (Evaporation Priestley-Taylor used in article)

* Not used in this model IGBP Biome types and configuration of internal parameters of the model

  • Code Description TcloseMinC TopenMaxC VPDClosePa VPDOpenPa ToptC BetaC kPa GaMs-1 GtotMs-1 GchMs-1 B1Sm-1 B2Sm-1 B3 b1* b2* b3* b4*
  • BENF Boreal Evergreen Needleleaf Forest -8 40 2800 500 12 25 150 0.03 0.002 0.08 208.3 8333.3 10
  • TENF Temperate Evergreen Needleleaf Forest -8 40 2800 500 25 25 200 0.03 0.004 0.08 133.3 888.9 6
  • EBF Evergreen Broadleaf Forest -8 50 4000 500 40 40 300 0.03 0.006 0.01 57.7 769.2 4.5
  • DBF Deciduous Broadleaf Forest -6 45 2800 650 28 25 200 0.04 0.002 0.01 85.8 694.7 4
  • MF Mixed Forest
  • CSH Closed Shrubland -8 45 3300 500 19 20 400 0.01 0.001 0.04 202 4040.4 6.5
  • OSH Open Shrubland -8 40 3700 500 10 30 50 0.005 0.012 0.04 178.6 178.6 8
  • WSV Woody Savannah -8 50 3200 500 32 28 900 0.002 0.0018 0.04 0.2 24000 6.5 57.1* 3333.3* 8* -0.01035*
  • SV Savannah -8 40 5000 650 32 30 800 0.001 0.001 0.04 790.9 8181.8 10
  • GRS Grassland -8 40 3800 650 20 30 500 0.001 0.001 0.04 175 2000 6
  • CRP Cropland -8 45 3800 650 20 30 450 0.005 0.003 0.04 105 3000 3

* For WSV when NDVI superior to 0.64"

SEE ALSO

i.evapo.pm
i.evapo.mh
i.evapo.senay
i.eb.netrad
i.eb.soilheatflux

REFERENCES

Zhang, K., Kimball, J.S., Nemani, R.R., Running, S.W. (2010). A continuous satellite-derived global record of land surface evapotranspiration from 1983 to 2006. WRR 46, W09522

Chemin, Y., 2012. A Distributed Benchmarking Framework for Actual ET Models, in: Irmak, A. (Ed.), Evapotranspiration - Remote Sensing and Modeling. InTech. (PDF, DOI: 10.5772/23571)

AUTHOR

Yann Chemin, GRASS Development Team, 2011

SOURCE CODE

Available at: i.evapo.zk source code (history)
Latest change: Friday Feb 21 10:10:05 2025 in commit 7d78fe3