Storm Hydrographs

Question 1

River Regime

Answer 1

Annual variation in discharge or flow of a river at a particular point or gauging station.

Question 2

Rising Limb

Answer 2

Part of a storm hydrograph which the discharge starts to rise

Question 3

Peak Discharge

Answer 3

The time when a river reaches its highest flow

Question 4

Falling Limb

Answer 4

Part of a storm hydrograph which the discharge starts to decrease

Question 5

Base Flow

Answer 5

The normal, day-to-day discharge of a river

Question 6

Lag Time

Answer 6

The time interval between peak rainfall and peak discharge.

Question 7

How would the shape of a storm hydrograph look in an area with Glacial Melts?

Answer 7

Low until spring where rising limb is rapid to peak in summer, and rapid recessional limb during autumn

Question 8

How would the shape of a storm hydrograph look in an area with Orographic rainfall / evapotranspiration?

Answer 8

Higher run-off during winter and lower during summer, however the change of run-off is gradual from each season

Question 9

How would the shape of a storm hydrograph look in an area with Tropical Seasonal Rainfall (monsoon)?

Answer 9

Extremely little to no run-off during the dry season, and extreme rising and falling limb during the wet season to a high peak.

Question 10

How would the shape of a storm hydrograph look in an area with Snowmelts?

Answer 10

relatively stable limbs during winter months with faster rising limb in spring, peak in June/July, with a more gradual falling limb.

Question 11

What are the two types of rivers to determine a storm hydrograph shape?

Answer 11

‘Flat’ River, and ‘Flashy’ River

Question 12

What are the components of a Flashy River?

Answer 12

Lower soil capacity, more impermeable surrounding rock, high drainage density with steeper banks.

Question 13

What are the components of a Flat River?

Answer 13

Higher soil capacity, less impermeable surrounding rock, lower drainage density with more shallow banks.