The quantity of liquid flowing per second through a section of a pipe or a channel is called discharge and is measured in cumecs (m3/ s). Mathematically, discharge,

Q = av

where

a = Cross-sectional area of the pipe, and

v = Average velocity of the liquid.

It may noted that

(a) The velocity of the liquid is maximum at the centre of a pipe and is minimum near the walls.

(b) 1 m3 = 1000 litres.