QUESTION $1[25$ MARKS$]$

The catchment area feeding into a reservoir is $50\mathrm{.}5k{m}^2.$ A uniform precipitation of $1\mathrm{.}2c\frac{m}{h}r$

for $2$ hours was observed to fall on the catchment on a particular day. It was found that $50\%$ of

the runoff transformed from the precipitation reached the reservoir. Meanwhile, a canal

carrying a flow of $2\mathrm{.}1\frac{m^3}{s}$ is taken from the reservoir. The rate of evaporation was recorded

as $1\mathrm{.}4m\frac{m}{h}\frac{r}{m^2}.$

$($a$)$ Assuming seepage loss to be $50\%$ of evaporation loss, estimate the change in the

reservoir level for $8$ hours if the area of the reservoir was $0\mathrm{.}45k{m}^2.$

$[15$ Marks$]$

$($b$)$ Determine the mean annual rainfall using Isohyetal Method

$[10$ Marks$]$