Causes of water insecurity

Question 1

Physical causes of water insecurity

Answer 1

• climate variability

- saltwater encroachment

Question 2

Climate variability - what this is and case study

Answer 2

Climate controls the annual and seasonal distribution of rainfall - rainfall varies globally due to atmospheric pressure systems - this determines its availiability for use as water supply.
E.g. The African Sahel is drought sensitive as it occupies a transitional clmate zone - mean annual rainfall is concentrated in the summer.

Question 3

Salt encroachment - what it is + case study

Answer 3

• the movement of saltwater into freshwater aquifers - due to sea level rise + abstraction of groundwater which lowers the water table.
  e.g. The pacific islands - 35% of Somoa’s water supply is drawn from aquifers + this increased in the Marshall Islands as it tripled due to droughts caused by 1997/8 el nino event.
  OR
  Los Angeles Basin coastal aquifers having this and without treatment = cant be drank or does not met agricultural standards.

Question 4

Human causes of water insecurity

Answer 4

• Overabstraction
• Contamination/pollution
• Agriculture
• Rising demand (due to increase in global pop + urbanisation)
• industrialisation

Question 5

Overabstraction - what is it + case study

Answer 5

When too much water is abstracted than able to be replenish = supplies diminish, estimated 20% of the world’s aquifers are over-exploited.
E.g. espacially effected in North China Plain - intensive farming area.
+ The Aral Sea - shrinking since 1960s - by 1994, levels fell by 16m, surface area decreased by 50%, vol decreased 75%, salinity increased 300%.

Question 6

Contamination/pollution - list of what its caused by + case study

Answer 6

intensive farming (chemical fertilisers leaching into water = eutrophication + hypoxia,) industrial waste (chemicals,) mining (dangerous metals,) untreated sewage (harmful bacteria) cause water quality to decrease. 
E.g. 20% of Bangladesh's tube wells sunk + these are used as water supplies but are unsafe due to high conc of arsenic - causing major arsenic poisoning.- caused by industrial/farming contamintes

Question 7

Agriculture - statistics of what its causing + causes

Answer 7

• Farming is the human activity (anthrogenic) that uses the largest amounts of water - 70% globally + 90% developing countries - this is caused by ineffienct use of water for crop production - causes aquifers to deplete, decrease in water flow, decrease in wildlife habitats + causes salinsation of 20% global irrigated land areas.
• causes eutrophication and hypoxia - these pesticides causing this are banned in developed countries due to harmful effects.

Question 8

Rising demand (increased global pop + urbanisation) - global statistics + case study

Answer 8

UN World Water Development Report 2015 - projected an increase in global water demand by 55% by 2050 - this is mainly due to growing demand from secondary industires (increase in thermal electricity generation + domestic use) - all linked to urbanisation.

• UN projects 40% global water deficit by 2030 under the ‘business as usual scenario’ - which will cause serious water insecurity.
  e. g. By 2030, urban pop in Africa + Asia predicted to double = further pressure on water resources.

Question 9

Industrialisation - global statistics + case studies

Answer 9

OECD report Environmental Outlook to 2050 predicted global water demand in manufacturing would increase by 400% from 2000 - 2050 (far more than any other sector) - most of this will be in developing and emerging countries = decrease in water supply + quality as increase in water pollution due to industrial spillage = contaminated groundwater + rivers.
By 2050, global agriculture will need to produce 60% more food to meet the demands of the growing pop.
e.g. In china, due to industrialisation - 75% of major lakes are classed as highly polluted, 300 mil use contaminated water daily + 190 mil suffer with water related illnesses annually.