i.evapo.pt - Computes evapotranspiration calculation Priestley and Taylor formulation, 1972.

       Yann Chemin, GRASS Development Team, 2007-08

i.evapo.pt  Calculates  the  diurnal  evapotranspiration  after   Prestley   and   Taylor   (1972).   The
       Priestley-Taylor  model  (Priestley  and  Taylor,  1972)  is  a modification of Penman’s more theoretical
       equation.

       imagery, evapotranspiration

i.evapo.pt  - Computes evapotranspiration calculation Priestley and Taylor formulation, 1972.

       RNETD optional output from i.evapo.potrad is giving good results as  input  for  net  radiation  in  this
       module.

       Alpha values:

           •   1.32 for estimates from vegetated areas as a result of the increase in surface roughness (Morton,
               1983; Brutsaert and Stricker, 1979)

           •   1.26  is  applicable  in  humid  climates  (De  Bruin and Keijman, 1979; Stewart and Rouse, 1976;
               Shuttleworth and Calder, 1979), and temperate hardwood swamps (Munro, 1979)

           •   1.74 has been recommended for estimating potential evapotranspiration in more arid regions (ASCE,
               1990). This worked well in Greece with University of Thessaloniki.
       Alpha values extracted from: Watflood manual.

i.evapo.mh,i.evapo.pm,i.evapo.time,i.eb.netrad,r.sun

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

       Accessed: Friday Apr 04 01:20:52 2025

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       © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual

GRASS 8.4.1                                                                                   i.evapo.pt(1grass)

i.evapo.pti.evapo.pt--helpi.evapo.pt  [-z]  net_radiation=namesoil_heatflux=nameair_temperature=nameatmospheric_pressure=namepriestley_taylor_coeff=floatoutput=name  [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:-z
           Set negative ETa to zero

       --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:net_radiation=name[required]
           Name of input net radiation raster map [W/m2]

       soil_heatflux=name[required]
           Name of input soil heat flux raster map [W/m2]

       air_temperature=name[required]
           Name of input air temperature raster map [K]

       atmospheric_pressure=name[required]
           Name of input atmospheric pressure raster map [millibars]

       priestley_taylor_coeff=float[required]
           Priestley-Taylor coefficient
           Default: 1.26output=name[required]
           Name of output evapotranspiration raster map [mm/d]