Question

In an irrigated area 12 m³/s of water is diverted to a $0.32k{m}^2$ field area for four hours. The soil moisture measurement in the field done after irrigation showed that 0.4 m of water has been stored in the root zone. The water application efficiency (correct to nearest decimal) in this case is:

• A. 85%
• B. 58.5%
• C. 74%
• D. 66.6%

Answer 1

The correct option is C 74%

$\text{Given, Area}=0.32{\text{km}}^2$

$\text{Time}\left(t\right)=4\text{hours}$

$\text{Depth of water in root zone}=0.4\text{m}$

$\text{Discharge}Q=12{\text{m}}^3\text{/s}$

$\text{Water application efficiency}\left({\eta }_a\right)=\frac{W_s}{W_F}$

$\text{Here,}{W}_s=\text{Quantity of water in root zone}$

$W_f=\text{Quantity delivered to field}$

$\therefore n_a=\frac{0.4\times 100}{\left(\frac{12\times 3600\times 4}{0.32\times {10}^6}\right)}=74.1\%$