i.evapo.zk - GRASS GIS manual

NAME

i.evapo.zk - Computes global evapotranspiration calculation after Zhang, Kimball, Nemani and Running formulation, 2010.

KEYWORDS

imagery, evapotranspiration

SYNOPSIS

i.evapo.zk

i.evapo.zk --help

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

Flags:

--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

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]

DESCRIPTION
NOTES
TODO
SEE ALSO
REFERENCES
AUTHOR

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"

SOURCE CODE

Available at: i.evapo.zk source code (history)

NAME

KEYWORDS

SYNOPSIS

Flags:

Parameters:

Table of contents

DESCRIPTION

NOTES

TODO

SEE ALSO

REFERENCES

AUTHOR

SOURCE CODE