5.1C

Question 1

Describe global water budgets

Answer 1

The global water budget limits water available for human use and water stores have different residence times; some stores are non-renewable (fossil water or cryosphere losses).

Question 2

What is a global water budget

Answer 2

The global water budget takes into account all the water that is held in stores and flows of the global hydrological cycle

Question 3

How much of the water budget is freshwater, easily accessible surface freshwater, glaciers/ice sheets

Answer 3

• only 2.5% of it is freshwater; the rest is in oceans.
• only 1% of all freshwater is ‘easily accessible surface freshwater’. - SHOCKING
• Nearly 70% is locked up in glaciers and ice sheets.

Question 4

Water budget in winter

Answer 4

precipitation higher than evapotranspiration so soil moisture surplus

Question 5

Describe uk water budget in spring

Answer 5

evapotranspiration increases above precipitation and soil utilises moisture

Question 6

Describe summer uk water budget

Answer 6

soil moisture deficit as evapotranspiration continues to rise

Question 7

Describe autmun uk water budget

Answer 7

precipitation increases as evapotranspiration decreases and soil moisture is recharged.

Question 8

Define water budget

Answer 8

The water budget is the annual balance between precipitation, evapotranspiration and runoff.

Question 9

Define base flow

Answer 9

water that’s usually available all year round (fossil water)

Question 10

Define surface flow

Answer 10

seasonal differences, e.g. monsoon, or cryosphere melting

Question 11

Why is fossil water a vulnerable (non-renewable) reserve

Answer 11

• Groundwater is extracted for drinking and other human activities.
• It can be replenished, but only if water can infiltrate that far.

Question 12

Define residence time

Answer 12

• average time a molecule of water will spend in one of the stores.

Question 13

Residence times in atmosphere, ocean and ice cap

Answer 13

Residence times vary from 10 days in the atmosphere to 3,600 years in the oceans and 15,000 years in an ice cap

Question 14

What two water stores and non-renewable

Answer 14

fossil and cryosphere

Question 15

What is fossil water

Answer 15

Ancient, deep groundwater made from pluvial (wetter) periods in the geological past

Question 16

What is cryosphere

Answer 16

• Made up of those areas of the world where water is frozen into snow or ice
• Is it non-renewable? This is to be questioned because, come another glacial period, more water will once again be locked in glaciers and ice sheets