Evapotranspiration (\( ET \)):

\[ ET = E + T \]

Where:

• \( ET \) is the evapotranspiration, in millimeters per day (mm/day).
• \( E \) is the evaporation, in millimeters per day (mm/day).
• \( T \) is the transpiration, in millimeters per day (mm/day).