5.3B

Question 1

River regimes indicate what?

Answer 1

indicate the annual variation of discharge

Question 2

What do river regimes result from

Answer 2

impact of climate, geology, soils

Question 4

What examples show these river regimes

Answer 4

yukon, amazon, indus or nile

Question 5

What cs is this?

Answer 5

yukon

Question 6

Define river regime

Answer 6

A river regime is the annual variation in the discharge or flow of a river at a particular point, and is usually measured in cumecs

Question 7

Define evapotranspiration

Answer 7

the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plant

Question 8

How does climate affect a river regime

Answer 8

• …the amount, seasonality and intensity of rainfall
• Temperature – determines evapotranspiration out
• Freezing conditions – flow is suspended

Question 9

How does geology affect river regime

Answer 9

• the porosity / perviousness of rocks
• Permeable rock recharges aquifer storage - groundwater is released steadily as base flow OR
• Impermeable rock results in a quick response to rainfall (water flows quickly to the river after heavy rain)

Question 10

permeable vs pervious

Answer 10

• porosity is the percent of open spaces or voids within a volume of soil or rock,
• permeability is the rate of water movement through interconnected pores within soil or roc

Question 11

How do soils affect river regimes

Answer 11

• Deep soils store water – slow release means a steadier river regime
• Permafrost can inhibit percolation (a slow regime) / but then melting rapidly increase water supply (flashy regime).

Question 12

define base flow

Answer 12

water that reaches the channel largely through slow throughflow and from permeable rock below the water table

Question 13

general factors affecting river regimes

Answer 13

▪ Channel capacity of the river
▪ Area and relief of the drainage basin
▪ Volume, pattern and intensity of precipitation
▪ Climate
▪ Geology of the soil (affecting the input of groundwater)
▪ Anthropogenic (human) activities, such as building dams or terracing the land

Question 14

Wheres does the Yukon, Alaska Canada start

Answer 14

Starts at northern end of Canadian Rockies at an altitude of 1,200 m – and flows over 3,000 km into Bearing Sea

Question 15

Which river has a comparable river regime to the yukon

Answer 15

Comparable river regimes to Siberian rivers (e.g. Yenisei) owing to its high sub-arctic latitude (60-66oN).

Question 16

Describe freezing in the yukon

Answer 16

• Sections of the river freeze over completely from mid-November (Winter)
• Permafrost (frozen soil) is discontinuous over its course with 50-90% coverage.
• increases surface run off and snow melts quickly

Question 17

Why might there be seasonal variation in river regimes

Answer 17

• periods of high discharge followed by low discharge which are due to glacial meltwater, snowmelt or monsoons
• which cause sudden fluctuations in river input.