The normal scour depth D below the designed flood level of a river may be calculated from the Lacey's equation, where C= Constant, Q = Design flood discharge and f=silt factor

A

D=C$$(\frac{Q}{f})$$

B

D=C$$(\frac{Q}{f})^{\frac{1}{2}}$$

C

D=C$$(\frac{Q}{f})^{\frac{5}{3}}$$

D

D=C$$(\frac{Q}{f})^{\frac{1}{3}}$$