What is the term for the amount of water flowing through a river channel, measured in cubic metres per second?

What is the term for the amount of water flowing through a river channel, measured in cubic metres per second?

• A. Discharge
• B. Runoff
• C. Flow rate
• D. Velocity

Answer: (A)

The main concept here is the quantity that describes how much water is moving past a point in a river per unit of time. The best term is discharge. Discharge represents the volume of water flowing through a cross-section of the river each second, so it is measured in cubic metres per second (m^3/s). A practical way to think about it is that discharge equals the cross-sectional area of the channel times the average speed of the water (Q = A × v). This distinguishes it from velocity, which is simply the speed of the water, and from runoff, which refers to water from rainfall that ends up in streams. Flow rate is a general everyday phrase, but in hydrology the standard name for this specific measure is discharge.

The main concept here is the quantity that describes how much water is moving past a point in a river per unit of time. The best term is discharge. Discharge represents the volume of water flowing through a cross-section of the river each second, so it is measured in cubic metres per second (m^3/s). A practical way to think about it is that discharge equals the cross-sectional area of the channel times the average speed of the water (Q = A × v). This distinguishes it from velocity, which is simply the speed of the water, and from runoff, which refers to water from rainfall that ends up in streams. Flow rate is a general everyday phrase, but in hydrology the standard name for this specific measure is discharge.