Water Use Efficiency (\( \xi_u \)):

\[ \xi_u = 100 \cdot \frac{W_u}{W_d} \]

Where:

• \( \xi_u \) is the water use efficiency, in percentage (%).
• \( W_u \) is the water beneficially used, in cubic meters (m³).
• \( W_d \) is the water delivered to the area being irrigated, in cubic meters (m³).