Concepts of System and Mass Balance

Question 1

What is the significance of inputs and outputs in the system?

Answer 1

They move to and from stores within the system, none cross the system boundaries.

Question 2

What is the amount of water fixed in the system?

Answer 2

1.38 million km3

Question 3

What does it mean for the mass balance when the amount of water is fixed?

Answer 3

The mass balance will not change.

Question 4

What are the main flows within the system?

Answer 4

Precipitation, evaporation, transpiration, cry-spherical processes and fluxes.

Question 5

What % of the worlds water does the ocean hold?

Answer 5

97%

Question 6

What % of the world water is in the cryosphere?

Answer 6

1.9%

Question 7

How does the oceanic store change?

Answer 7

Sea level change - eustatic change has resulted in significant change over time.
During glacials, more water is frozen, decreasing water holding capacity.
Climate warming increases ice sheet melting, raising sea levels.

Question 8

How have changes in cryosphere processes affected the global water stores?

Answer 8

Short-term changes in accumulation and ablation occur annually due to seasonal temperature changes
Climatic changes in inter/glacials, cause significant changes in cryosphere size.
Human-induced global warming is permanently reducing the cryosphere by increasing ablation.

Question 9

What are the processes that control transfers in the water cycle?

Answer 9

Short-term storm events increase local transfers.
Seasonal variations in climate impact on transfer rates (monsoon season)
Climatic variability due to events lasting years such as the El Niño Southern Oscillation impacts precipitation
Global Warming impacts on precipitation and evaporation, influencing land-atmosphere flows.
Climate change impacts on ablation rates, affecting transfers between cryosphere and other parts.

Question 10

what is a drainage basin?

Answer 10

A subsystem of the global water cycle - it is open because water crosses the boundaries of the basin.

Question 11

What is the input to a drainage basin?

Answer 11

Precipitation: type, amount, duration and intensity influence transfers and stores in the system.

Question 12

What is the drainage basin flow throughfall?

Answer 12

Water dripping from plants from plants to the ground - influenced by leaf canopy

Question 13

What is the drainage basin flow stem flow?

Answer 13

Water flowing down stems and trunks

Question 14

What is the drainage basin flow infiltration?

Answer 14

Water soaking into the soil - infiltration rate is the rate at which water can pass into the soil.

Question 15

What is the drainage basin flow overland flow?

Answer 15

Saturation excess overland flow - soil is saturated and cannot hold any more moisture
Infiltration excess overland flow - rainfall intensity is so great it exceeds infiltration rate

Question 16

What is the drainage basin flow throughflow?

Answer 16

low lateral movement downslope through the soil.

Question 17

What is the drainage basin flow percolation?

Answer 17

Downward movement from soil to underlying rock.

Question 18

What is the drainage basin flow groundwater flow?

Answer 18

Slow, downward and lateral movement through bedrock.

Question 19

What is the drainage basin flow channel flow?

Answer 19

Flow of water in streams and rivers.

Question 20

What is the drainage basin Interception store?

Answer 20

Water held on leaf and plant surfaces

Question 21

What is the drainage basin vegetation store?

Answer 21

Water contained in plants

Question 22

What is the drainage basin surface store?

Answer 22

Water collected in depressions in the ground surface, includes snow cover

Question 23

What is the drainage basin groundwater store?

Answer 23

Water stored in underground rocks; the water table marks the upper level of saturated rock.

Question 24

What is the drainage basin output evaporation?

Answer 24

Water changing state from a liquid to water vapour - occurs from any surface store or flow

Question 25

What is the drainage basin output transpiration?

Answer 25

Release and evaporation of water from vegetation.

Question 26

What is the drainage basin output channel discharge to oceans?

Answer 26

The volume of water leaving a drainage basin and flowing into the sea.