Water Requirement (\( WR \)):

\[ WR = ET + P \]

Where:

• \( WR \) is the water requirement, in millimeters per day (mm/day).
• \( ET \) is the evapotranspiration, in millimeters per day (mm/day).
• \( P \) is the percolation, in millimeters per day (mm/day).