Flood hydrograph

Question 1

Discharge

Answer 1

Volume of water in cubic metres that flows in a river per second or cumecs

Question 2

Lag time

Answer 2

Delay between peak rainfall and peak discharge

Question 3

Rising limb

Answer 3

Part of the graph going up to peak discharge. River discharge increases as rainwater flows into the river

Question 4

Fallin limb

Answer 4

part of the graph after peak discharge. Discharge decreases as less water flows into the river. Also called receding limb.

Question 5

Base flow

Answer 5

Starting and finishing level of a river

Question 6

Peak discharge

Answer 6

highest flow in the channel

Question 7

Hydrograph

Answer 7

River discharge over time. Shows how the volume of water flowing at a certain point changes over time.

Question 8

Drainage basin characteristics

Answer 8

Large- catch more precipitation, higher peak discharge
Steep-sided- short lag time, increase peak discharge
Circular- Flashy hydrograph. Increase peak discharge.

Question 9

Water a;ready present

Answer 9

Waterlogged= no infiltration and more surface runoff. Reduce lagtime

Question 10

Soil type

Answer 10

Sandy soils- high infiltration
Clay- low infiltration