Question

Lacey's scour depth for a stream carrying a discharge of 3 cumecs per meter width having a silt factor 1.2 is_____m

• A. 2.64

Answer 1

The correct option is A 2.64

Lacey's scour depth.

$R=1.35{\left(\frac{q^2}{f}\right)}^{1/3}$

f = silt factor = 1.2
q = discharge per meter width

= $3m^3/s/m$

$\therefore R=1.35{\left(\frac{q^2}{f}\right)}^{1/3}=1.35\times {\left(\frac{9}{1.2}\right)}^{1/3}$

R = 2.64 m