# Mean Depth

on . Posted in Fluid Dynamics

Mean depth, abbreviated as $$h_m$$, is the average water depth in a stream channel or conduit computed by dividing the cross-section area by the surface width.

## Mean depth formula

$$\large{ h_m = \frac{ A_c }{ T } }$$

$$\large{ h_m = \frac{ v^2 }{ g \; Fr^2 } }$$

Symbol English Metric
$$\large{ h_m }$$ = mean depth $$\large{ ft }$$ $$\large{ m }$$
$$\large{ A_c }$$ = area cross-section of flow $$\large{ ft^2 }$$ $$\large{ m^2 }$$
$$\large{ Fr }$$ = Froude number $$\large{ dimensionless }$$
$$\large{ g }$$ = gravitational acceleration $$\large{ \frac{ft}{sec^2} }$$ $$\large{ \frac{m}{s^2} }$$
$$\large{ T }$$ = top of water surface width $$\large{ ft }$$ $$\large{ m }$$
$$\large{ v }$$ = velocity of flow $$\large{ \frac{ft}{sec} }$$ $$\large{ \frac{m}{s} }$$