Fresh Water

1

• Fresh Water
• Historically limiting factor in arid regions
• 1940-1990
• World population more than doubled
• 2.3 billion ? 5.3 billion
• Per capita water use doubled
• 400 m3 person-1 year-1 ? 800 m3 person-1 year-1
• Global water use increased fourfold
• 2000 USA 2000 m3 person-1 year-1 (1450 gal
  day-1)
• Current Status
• In 1996, world human population using estimated
  54 of all accessible fresh water in rivers,
  lakes, aquifers
• Many people predict disastrous consequences for
  worlds fresh water supply in coming years
• This potential disaster may have several causes

2

• Fresh Water
• Current Status
• Distribution
• Uneven compared to population
• 75 of annual rainfall in areas containing less
  than one-third of global population
• Amazon River carries 20 of global runoff through
  area containing 10 million people
• Congo River carries 30 of Africas runoff
  through area containing 10 of population
• Uneven in space
• North America contains 19,000 m3 per person per
  year vs. 4700 m3 per person per year in Asia
• lt10 of Mexico supplies gt50 of annual runoff
• Uneven in time
• India gets 90 of annual rainfall during summer
  monsoon season (Jun-Sep) runs off too rapidly
  for efficient use

3

• Fresh Water
• Current Status
• Usage patterns
• Agriculture 69
• Industry/Energy 23
• Domestic 8
• Varies among regions and with development
• Africa 88 for agriculture (irrigation)
• Europe gt50 for industry
• Japan Industrial but uses lots of water for
  growing rice
• Spain/Portugal Arid water used heavily for
  agriculture
• Personal use tracks standard of living
• Africa 17 m3 year-1 (47 l d-1)
• Asia 31 m3 year-1 (85 l d-1)
• UK 122 m3 year-1 (334 l d-1)
• US 211 m3 year-1 (578 l d-1)
• By 2020, water shortages likely in Ethiopia,
  India, Kenya, Nigeria, China (parts of China
  already face problems)
• Mexico City uses groundwater for 80 of municipal
  water supply

4

• Fresh Water
• Current Status
• Contamination
• Numerous examples worldwide
• Biggest source Agriculture
• Europe Over 90 of rivers have elevated
  nutrient levels from agrochemicals
• Hungary Nearly 40 of well fields contaminated
• Developing countries On average, 90 to 95 of
  all domestic sewage and 75 of all industrial
  waste discharged into surface waters without
  treatment
• Impacts
• Nile River Diverting water retention of
  sediment behind dams has caused fertile delta to
  shrink
• Rhine River Lost 8 of 44 fish species 25 more
  endangered
• Lake Chad Diversion drought has caused
  shrinkage from 25,000 to 2,000 km2 in 30 years
  Link
• Aral Sea Diversion for agriculture has caused
  severe shrinkage, with environmental health
  problems L1 L2

5

• Fresh Water
• Consequence Conflicts
• World may have enough fresh water but uneven
  distribution ? disputes, though few outright wars
• Middle East Most acute water conflicts
• Jordan River Basin
• River originates in Lebanon
• Water shared by six nations (Wolf et al. 2005)
• Israel 467 m3 person-1 year-1
• Jordan 224 m3 person-1 year-1

6
(No Transcript)
7

• Fresh Water
• Consequence Conflicts
• Jordan River Basin
• 1951
• Jordan announces plans to irrigate Jordan Valley
  by tapping Yarmuk R. (major tributary)
• Israel drains swamps between Israel Syria
• Military clash between Israel Syria
• 1953
• Israel begins construction of National Water
  Carrier to transfer water from Jordan basin to
  Negev Desert for irrigation
• Syria responds with military action
• Israel changes intake to Sea of Galilee
• 1965
• Palestinian National Liberation Front attacks
  diversion pumps operated by Israeli NWC
• 1960
• Arab leaders agree on plan to divert headwater
  via Yarmuk R. to East Ghor (King Abdullah) Canal
  (Jordan)
• 1965-66
• Syria announces plans to divert headwaters
• Military clash between Israel Syria