Hargreaves

Luo_Suppe2026-08-15

gma.climet.et0.Hargreaves

function Hargreaves(tmax, tmin, lat = 34.6, TMean = None, axis = None, start_year = 1992, start_day_of_year = 1):

Calculate daily potential evapotranspiration based on the Hargreaves (1998) method.

Parameters:

tmax: float||array.

Daily maximum temperature (��).

tmin: float||array.

Daily minimum temperature (��).

Optional:

lat = float||array. Default 34.6�� N.

Data latitude value (��).

*Note: If lat is an array, it should have the same shape as the input data on the non-computed axis!

TMean = float||array. Default None.

Daily maximum temperature (��). The default (None) is (tmax + tmin) * 0.5.

axis = int. Default None.

Calculation axis. If not set (None), multidimensional data will be expanded to 1 dimension for calculation.

start_year = int. Default 1992.

Data start year.

start_day_of_year = int. Default 1.

Data start day of year.

*Note: start_year, start_month are based on calculated axis!

Returns:

Type: array.

References.

Allen, Richard et al (1998) Crop evapotranspiration - Guidelines for computing crop.

water requirements - FAO Irrigation and drainage paper 56.

ISBN 92-5-104219-5.