option A water scarcity and quality

Question 1

water scarcity types:

Answer 1

-physical water scarcity
-economic water scarcity

Question 2

physical water scarcity

Answer 2

-where water consumption exceeds 60% of unusable supply

Question 3

economic water scarcity

Answer 3

• physically sufficient water to meet needs but requires additional storage and and transport facilities

Question 4

drought

Answer 4

an extended period of dry weather leading to conditions of extreme dryness

Question 5

absolute drought

Answer 5

at least 15 consecutive says with less than 0.2 mm of rainfall

Question 6

water quantity dependency

Answer 6

-rates of rainfall
-evaporation
-use of water by plants (transpiration)
-river and groundwater flow

Question 7

water stress

Answer 7

less than 1700 m^2 water per year

Question 8

water use implications

Answer 8

-half of world’s wetlands disappeared
-20% of freshwater species are endangered or extinct
-many important aquifers are being depleted
-water tabled in many parts of world are falling at an alarming rate.

Question 9

factors affecting access to safe water

Answer 9

-water availability
-water infrastructure
-cost of water

Question 10

factors that may affect water quality

Answer 10

-organic waste
-fertilizers
-pesticides
-heavy metals
-acids

Question 11

environmental consequences of agriculture on water quality

Answer 11

-eutrophication
-salinization
-irrigation (overwatering)

Question 12

eutrophication

Answer 12

-Increased amount of nitrogen and phosphorus carried in streams, lakes and groundwater causing nutrient enrichment.
results in increased algal blooms.
-increase in algae and plankton shade the water cutting off light supply for submerges plants
-water anoxia as all the oxygen is taken up and no plants are left to synthesise
-dead zones.

Question 13

issues with increased nitrogen in water

Answer 13

-eutrophication
-loss of fertiliser=economic burden on farmer
-increase on nitrogen in drinking and irrigation water may impact human health.

Question 14

ways of dealing with eutrophication

Answer 14

-altering pollution causing human activities (alternative fertilisers or detergent)
-regulating and reducing pollutants (sewage treatment plants that remove nitrates and phosphates from waste)
-restoring water quality by pumping mud from eutrophic lakes

Question 15

eutrophication stakeholders

Answer 15

-farmers who apply fertiliser and have increased farm yields
-chemical companies profiting from from fertiliser sales
-government that may begin to achieve food security
-customers who receive more reliable food supplies and benefit from lower prices
-water companies providing water to consumers

Question 16

irrigation
overwatering

Answer 16

watering of crops
irrigation using techniques such as flooding (paddy fields)

Question 17

impacts of irrigation

Answer 17

-salinisation
-water insecurity
-lower water quality (fertilisers seeping into drinking water)
-harming marine ecosystems (synthetic fertilisers)
-lower albedo- rise in temperatures

Question 18

salinisation

Answer 18

increase of the amount of salt in the soil

Question 19

how does salinisation occur

Answer 19

groundwater levels are close to surface- capillary forces bring water to surface where it may be evaporated leaving behind any soluble salts carried.

Question 20

impacts of growing pressure on rivers

Answer 20

-pollution
-water volume loss
-water getting saltier
-loss of ecosystems

Question 21

wetlands

Answer 21

lands with soils that are permanently flooded
-6% of world habitats

Question 22

management technology

Answer 22

-nanotechnology infiltration
-memebrane chemistry
seawater desalination

Question 23

water purification methods

Answer 23

-filtration
-sedimentation
-desalination

Question 24

efficient use/storage of water

Answer 24

-irrigation of individual plants rather than whole fields
-covering expanses for water with plastic or chemical to reduce evaporation
-storage of water underground in gravel-filled reservoirs (reduce evaporation losses)