5.1

Question 1

Why is there a global freshwater crisis?

Answer 1

2.5% of the worlds water is fresh, 1.2% of that water is on the surface and 72% of the fresh surface water is in glaciers, permafrost and the atmosphere, making only 23% of it accessible. All together this means only 0.0069% of the worlds water is suitable for our needs.
On top of the limited supply, the supply of fresh water is decreasing whilst the demand is increasing

Question 2

Describe the drainage basin hydrological cycle

Answer 2

Precipitation -> interception -> output through transpiration. or through fall/stem flow -> surface storage
From surface storage
1) transpiration output or Evaporation output
2) surface run-off -> channel store -> river channel flow out to basins e.g. lake or ocean
3) infiltration -> sub surface storage, sun surface through flow to channel store may occur or, percolation -> groundwater store -> ground water flow -> channel store

Question 3

Define Blue and green water

Answer 3

Blue water:
-Fresh water stored in rivers, streams and lakes (visible part of hydrological cycle)

Green water:
-Fresh water stored in soil and vegetation, the invisible part of the hydrological cycle

Question 4

What is the: percentage store, residence time and flows in 10^3km^3 per year of Oceans

Answer 4

Percentage store: 97
Residence time: 3,600 years
Flows: (373) Ocean atmosphere (373)

Question 5

What is the: percentage store, residence time and flows in 10^3km^3 per year of Cryosphere

Answer 5

Percentage store: 2
Residence time: 15,000
Flows: bleh

Question 6

What is the: percentage store, residence time and flows in 10^3km^3 per year of terrestrial plain

Answer 6

Percentage store: 1.11
Residence time: 1 week - 10,000 years
Flows: (113) land atmosphere (73)

Question 7

What is the: percentage store, residence time and flows in 10^3km^3 per year of atmosphere

Answer 7

Percentage store: 0.01
Residence time: 10 days
Flows:
(113) land  atmosphere (73)
(373) ocean  atmosphere (373)

Question 8

What is a non-renewable source of water

Answer 8

Fossil water: an ancient body of water which had been contained in an undisturbed space, typically groundwater in an aquifer
E.G. Potato farms in Egypt and Algeria

Question 9

What is a renewable source of water

Answer 9

The global hydrological cycle: consumed water is released out as vapour after respiration and or excretion and put back into the hydrological cycle

Question 10

define fluxes/flows

Answer 10

measure of the rate of flow between stores

Question 11

define processes

Answer 11

physcial measurments such as evaporation that drive the flows between stores

Question 12

define stores/stocks

Answer 12

resevoir where water is held e.g. oceans

Question 13

where does our water come from

Answer 13

-70% of Londons water is supplied by reservoirs which collect the water from the ricer thames from western London where it is then treated

Question 14

what drought precautions does London have

Answer 14

• North London Artificial Recharge Scheme which uses chalk aquifiers beneath Enfield, Harningey and Lee Valley to top up supplies
• Used in 1997, 2003. 2005 and 2006
• It is enough for 1.2m Londoners