Question

A canal was designed to supply the irrigation needs of 1200 hectares of land growing rice of 140 days base period having a Delta of 134 cms. If this canal water is used to irrigate wheat of base period 120 days having a Delta of 52 cm, the area (in Hectares) that can be irrigated is

• A. 2650
• B. 3608
• C. 543
• D. None of the above solution

Answer 1

The correct option is A 2650

$\Delta \left(cm\right)=\frac{8.64B}{D}$

$\Delta =\text{Delta in cm}$
$B=\text{Base period in days}$
$D=\text{Duty in hectares/cumec.}$

Duty for rice,

$D_{rice}=\frac{8.64B}{\Delta }=\frac{8.64\times 140}{1.34}$

= 902.6 ha/cumec

$\therefore \text{Discharge from canal,}$
$Q=\frac{Area}{Duty}$

$=\frac{1200}{902.6}=1.3294cumec$

Now duty for wheat,

$D_{wheat}=\frac{8.64\times B}{\Delta }$

$=\frac{8.64\times 120}{0.52}=1993.846ha/cumec$

$NowQ=\frac{Area}{Duty}$

$\therefore \text{Area}=1993.846\times 1.3294$
$=2650.62hectares$