ETo_Hrg {FAO56}

Hargreaves Reference Evapotranspiration (ETo) Equation

Description

ETo_Hrg returns the value of the evapotranspiration rate from the reference surface.

Usage

ETo_Hrg(T_min, T_max, R_a)

Arguments

T_min

Optional. A numeric scalar that denotes the daily minimum temperature [C].

T_max

Optional. A numeric scalar that denotes the daily maximum temperature [C].

R_a

A numeric scalar denotes the extraterrestrial radiation [MJ/(m^2\times day)].

Details

This is a function to calculate the evapotranspiration rate from the reference surface (ETo) by using Hargreaves equation.

Value

The function returns the value of evapotranspiration rate from the reference surface calculated by Hargreaves equation [mm/day] as a numeric scalar.

Reference

Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. (1998). Crop evapotranspiration - Guidelines for computing crop water requirements - FAO Irrigation and drainage paper 56. Fao, Rome, 300(9), D05109.

See Also

ETo_FPM for FAO Penman-Monteith Equation.

Examples

ETo_Hrg(T_min = 19, T_max = 25, R_a = 32)