Question

An S-curve hydrograph has been obtained for catchment of $270k{m}^2$ from a 3 hour unit hydrograph. The equilibrium discharge for the S-curve is

• A. $750m^3/s$
• B. $277.8m^3/s$
• C. $250m^3/s$
• D. $187m^3/s$

Answer 1

The correct option is C $250m^3/s$

The equilibrium discharge is expressed as
$Q_s=\frac{A}{D}\times {10}^4{m}^3/h$

where A is area of catchment in $k{m}^2$ and D is duration in hours.

$\therefore Q_s=\frac{270}{3}\times {10}^4$
$=90\times {10}^4{m}^3/h$
$=\frac{90\times {10}^4}{3600}{m}^3/s$
$=250m^3/s$