Question

For a reservoir having 100 ha surface area, the saturation vapour at 30${}^0$C is 35 mm of Hg and actual vapour pressure at 9 m is found out to be 50% of the saturation vapour pressure. If wind velocity at 2 m above the ground is 12 kmph then average daily evaporation from lake reservoir will be _________mm/d.
[Use Meyer's formula and take $k_m=0.36$]

• A. 12.16

Answer 1

The correct option is A 12.16
E = k${}_m(e_s-e_a)(1+\frac{V_9}{16}$)
Given k${}_m$=0.36
e${}_s$ = 35 mm of Hg
$\therefore e_a$ = 17.5 mm of Hg
$\frac{V_9}{V_2}=(\frac{9}{2}{)}^{0.143}$
$\Rightarrow V_9=14.88km/hr$
$\therefore E=0.36(35-17.5)(1+\frac{14.88}{16})=12.16mm/d$