Question

For a given discharge, the critical flow depth in an open channel depends on
1. channel geometry only
2. channel geometry and bed slope
3. channel geometry, bed slope and roughness
4. channel geometry, bed slope, roughness and Reynold's number

Answer 1

Correct Answer - Option 1 : channel geometry only

Concept:

Critical depth of flow yc is given by

\({{\rm{y}}_{\rm{c}}} = {\left( {\frac{{{q^2}}}{g}} \right)^{\frac{1}{3}}}\)

​q = discharge per unit width

Hence it can be said that the critical depth depends only on the geometry of the channel and the discharge through the channel.