The width of the river is 20 m, the average depth is 1.5 m, the speed of the river is 2 m / s. Determine the flow rate of the river in this area.

Water discharge is the volume of water that flows per unit of time through the cross section of a river. The unit of water discharge is usually taken as 1 m3 / s or 1 km3 / year.
1) Find the cross-sectional area of the river:
F = 20 m × 1.5 m = 30 m2
2) Find the flow rate in the river:
Q = F × V = 30 m2 × 2 m / s = 60 m3 / s
Answer: the water discharge in the river in this section is 60 m3 / s.