REVISION AS CAMBRIDGE GEOGRAPHY: RIVERS - DISCHARGE.

1. AS GEOGRAPHY
HYDROLOGY
4 QUESTIONS
REVISION
DISCHARGE

2. DEFINITION
Discharge is the volume of water passing a particular point over a given
unit of time.

3. QUESTION 1
How is discharged calculated?

4. ANSWER
Cross sectional area x average velocity.

5. QUESTION 2
What units are normally used to express discharge?

6. ANSWER
Cumecs (cubic metres per second).

7. QUESTION 3
Why does discharge usually increase downstream?

8. ANSWER
The cross-sectional area increases downstream (because of inputs
from tributaries and underground sources) and/or velocity increases.

9. QUESTION 4
Why does discharge vary over time?

10. ANSWER
Precipitation varies, for instance during a storm or in times of drought.

11. IMPORTANT
It is important to appreciate that discharge is a rate, not an absolute
amount, as it is measured per unit of time.
It is the standard measure of river flow used at gauging stations and can
provide a good opportunity for fieldwork on a small river using simple
equipment.