DESCRIPTION
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.
NOTES
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.
SEE ALSO
i.evapo.mh,
i.evapo.pm,
i.evapo.time,
i.eb.netrad,
r.sun
AUTHORS
Yann Chemin, GRASS Development team, 2007-08
Last changed: $Date$