Question

The base width of the triangular 4 hour hydrograph (depth = 1 cm ) plotted for the catchment having area 275 $k{m}^2$ and having peak discharge of 37 $m^3/s$ is ____________hr

• A. 41.29

Answer 1

The correct option is A 41.29
Let B be the base width 4 hr unit hydrograph.
Volume represented by the area of unit hydrograph = Volume of 1 cm depth over the catchment
$\frac{1}{2}\times B\times 60\times 60\times 37=275\times {10}^6\times \frac{1}{100}$
$\Rightarrow$ B = 41.29 hours