Gross Depth of Irrigation:

\[ Id = \frac{100 \cdot Idn}{TR \cdot EU} \]

Where:

• \(Id\) is the gross depth of irrigation in millimeters (mm).
• \(Idn\) is the maximum net depth of each irrigation application in millimeters (mm).
• \(TR\) is the ratio of transpiration to application, typically 0.9.
• \(EU\) is the emission uniformity in percentage (%).