Stream power
Stream power is a geomorphology concept that is a measure of the available energy a stream has for moving sediment, rock, or woody material. For a cross section, the total stream power per unit length of channel may be formulated as:
where:
γ = unit weight of water (lb/ft3)
Q = discharge (ft3/s)
Sf = energy slope (ft/ft)
v = velocity (ft/s)
w = channel width (ft)
d = hydraulic depth (ft)
English units are pounds per second per foot of channel length. A second formulation, unit stream power, is the stream power per unit of bed area:
where:
τ = bed shear stress
v = average velocity
A third formulation relates stream power per unit weight of water:
where the terms are as previously defined.