Question

A stable channel is to be designed for a discharge of $Q{m}^{3/}s$ with silt factor f as per Lacey's method. The mean flow velocity (m/s) in the channel is obtained by

• A. ${\left[\frac{Q{f}^2}{140}\right]}^{1/6}$
• B. ${\left[\frac{Q{f}^2}{140}\right]}^{1/3}$
• C. ${\left[\frac{Q^2{f}^2}{140}\right]}^{1/6}$
• D. ${0.48\left[\frac{Q}{f}\right]}^{1/3}$

Answer 1

The correct option is A ${\left[\frac{Q{f}^2}{140}\right]}^{1/6}$

Mean flow velocity

$v={\left[\frac{Q{f}^2}{140}\right]}^{1/6}$