Hydrographs Flashcards
0
Q
Rainfall volume =
A
Bar chart x surface area
1
Q
Lag time:
A
The time between max rainfall and peak discharge.
2
Q
The return period, use for flood prediction, is…
A
The discharge plotted against time interval before a similar discharge occurs again.
3
Q
The river stage (river height) is the….
A
Elevation of water surface above a fixed height - used for flood warnings.
4
Q
Base flow (B) is estimated by
A
The horizontal line at the bottom of the stream discharge line.
5
Q
Annual variation: (3)
A
Base flow maintains the flow of rivers in dry periods.
High base flow levels at the end of winter from seasonably high precipitation.
Decline throughout summer into autumn - evaporation is higher than precipitation.
