Mismanagement of river basins, watersheds and lakes

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Mismanagement of river basins, watersheds and
lakes

• Freshwater and the hydrological cycle
• Water hot spots in the world
• How to deal with water scarcity
• Global warming and water scarcity

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Water hot spots
http//news.bbc.co.uk/2/shared/spl/hi/world/03/wor
ld_forum/water/html/mexico_city.stm
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The Aral Sea in Central Asia was once the world's
fourth biggest inland sea, and one of the world's
most fertile regions. But economic mismanagement
has turned the area into a toxic desert. The two
rivers feeding the sea, the Amu Darya and the Syr
Darya, were diverted in a Soviet scheme to grow
cotton. Between 1962 and 1994, the level of the
Aral Sea fell by 16 metres. The surrounding
region now has one of the highest infant
mortality rates in the world, and anaemia and
cancers caused by chemicals blowing off the dried
sea bed are common.
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CausesLake Chad, once a huge lake straddling the
borders of Chad, Niger, Nigeria and Cameroon, has
shrunk by 95 since the mid 1960s. The region's
climate has changed during that time, with the
monsoon rains which previously replenished the
lake now greatly reduced. A recent study blamed
human activities combined with local weather
changes, not global warming. It said overgrazing
had destroyed the savannah vegetation which
itself influenced the weather patterns. As the
climate has become drier, the demand for water to
irrigate food crops has increased quadrupling
between 1983 and 1994 - depleting the lake
further. Nine million farmers, fishermen, and
herders in the region now face water shortages,
crop failure, livestock deaths, collapsed
fisheries, soil salinity and increasing poverty.
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Mexico City is sinking because of the amount of
water being pumped out from beneath its
foundations. One of the largest and most populous
cities in the world, it was once a lush land of
lakes. But over the last 500 years the lakes have
been drained and the surrounding forests chopped
down. As the city grew in size, the water problem
magnified. With no adequate drainage system,
today rainwater mixes with sewage and is used for
irrigation. The city is now at serious risk of
running out of clean water. An estimated 40 of
the city's water is lost through leaky pipes
built at the turn of the century.
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Mexico city (20 million people) In the last 100
years the city has sunken more than 9 meters. As
a consequence the walls of the buildings are
buckled. 23 steps have recently to be added to
the independence monument (1900).
1 to 4 people have no access to water. 40 of
water from aquifer is wasted due to inadequate
piping system
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River Nile A United Nations report has predicted
that access to water may be the single biggest
cause of conflict and war in Africa in the next
25 years. Experts have warned that if populations
rise as expected in Egypt, Ethiopia and Sudan -
the three countries most dependent on the Nile -
competition for its waters will be intense. Cairo
said in 1991 that it was ready to use force to
protect its access to the 7,000km-long river,
which with its tributaries runs through nine
countries. However, recent years have seen Egypt,
Ethiopia and Sudan agree to use the river
equitably and apply the principles of sustainable
development.
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Turkey Water-rich by Middle-Eastern standards,
Turkey has in recent years undertaken an
ambitious project to sell water from its Manavgat
river across the region. It is still vulnerable
to shortages, however - just a few weeks after
Turkey agreed to sell water to Israel, officials
were warning of a water crisis. Another project,
a system of 22 dams on the Tigris and Euphrates
rivers, has provoked criticism from downstream
neighbours Iraq and Syria.
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China's urban community suffers most from water
scarcity. In 1990, about 26 percent of the total
population lived in cities, increasing to 35
percent (or 450 million) 2000. Water scarcity
also remains a serious threat to the nation's
food self-sufficiency. About 70 percent of the
grains produced in China are cultivated on
irrigated land. Food security is expected to
worsen with the expected population rise from 1.2
billion to 1.5 billion in 2030.
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Water consumption PRC 550 billion m3 (2000)
National water use in China
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• Panting schemes to reduce soil erosion (Mu Us
  desert northwestern of China)

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South-to North water diversion project
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Water scarcity

• Freshwater and the hydrological cycle
• Water hot spots in the world
• How to deal with water scarcity
• XXXX
• XXXX
• Global warming and water scarcity

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VALUING WATER

• Dublin Statement on Water and Sustainable
  Development (1992)'Principle No. 4 Water has
  an economic value in all its competing uses and
  should be recognized as an economic good. Within
  this principle, it is vital to recognize first
  the basic right of all human beings to have
  access to clean water and sanitation at an
  affordable price. Past failure to recognize the
  economic value of water has led to wasteful and
  environmentally damaging uses of the resource.
  Managing water as an economic good is an
  important way of achieving efficient and
  equitable use, and of encouraging conservation
  and protection of water resources.
• Agenda 21, Chapter 18 (UNCED, 1992)'Water
  should be regarded as a finite resource having an
  economic value with significant social and
  economic implications regarding the importance of
  meeting basic needs.
• Ministerial Declaration of the 2nd World Water
  Forum (The Hague, 2000)'To manage water in a
  way that reflects its economic, social,
  environmental and cultural values for all its
  uses, and to move towards pricing water services
  to reflect the cost of their provision. This
  approach should take account of the need for
  equity and the basic needs of the poor and the
  vulnerable.
• Ministerial Declaration of the 3rd World Water
  Forum (Kyoto, 2003)'Funds should be raised by
  adopting cost recovery approaches which suit
  local climatic, environmental and social
  conditions and the "polluter-pays" principle,
  with due consideration to the poor. All sources
  of financing, both public and private, national
  and international, must be mobilized and used in
  the most efficient and effective way.'

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Water pricing in developed countries
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When the supply systems are deficient, the poor
are the first to suffer. Those who do not benefit
from a house connection are often forced to
obtain water from informal street vendors at a
much higher price.The table below shows house
connection prices versus informal vendor prices
(in US) in selected developing countries.
City Cost of water for domestic use (a)(house connection 10 m3/month) in US/m3 Price charged by informal vendors (b) in US/m3 Ratio (b/a)
Vientiane (Lao PDR) 0.11 14.68 135.92
Male (Maldives) 5.70 14.44 2.53
Mandalay (Myanmar) 0.81 11.33 14.00
Faisalabad (Pakistan) 0.11 7.38 68.33
Bandung (Indonesia) 0.12 6.05 50.00
Delhi (India) 0.01 4.89 489.00
Manila (Philippines) 0.11 4.74 42.32
Cebu (Philippines) 0.33 4.17 12.75
Davao (Philippines) 0.19 3.79 19.95
Chonburi (Thailand) 0.25 2.43 9.57
Phnom Penh (Cambodia) 0.09 1.64 18.02
Bangkok (Thailand) 0.16 1.62 10.00
Ulaanbaatar (Mongolia) 0.04 1.51 35.12
Hanoi (Viet Nam) 0.11 1.44 13.33
Mumbai (India) 0.03 1.12 40.00
Ho Chi Minh City (Viet Nam) 0.12 1.08 9.23
Chiangmai (Thailand) 0.15 1.01 6.64
Karachi (Pakistan) 0.14 0.81 5.74
Lae (Papua New Guinea) 0.29 0.54 1.85
Chittagong (India) 0.09 0.50 5.68
Dhaka (Bangladesh) 0.08 0.42 5.12
Jakarta (Indonesia) 0.16 0.31 1.97
Colombo (Sri Lanka) 0.02 0.10 4.35
Some water vending, but not common. Some water vending, but not common. Some water vending, but not common. Some water vending, but not common.
In some countries, water from informal vendors is
over 100 times more expensive than water supplied
by house connection. Source information
extracted from Second Water Utilities Data Book,
Asian Development Bank, 1997.
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Ecosystems valueThe multiple roles of the
aquatic ecosystems, called ecosystems services,
present an economic value to water.
Ecosystem type Total value per hectare (US/year) Total global flow value (US billion/year)
Tidal marsh/mangrove 6,075 375
Swamps/floodplains 9,990 1,648
Lakes/rivers 19,580 3,231
Total   5,254
Global and per hectare values of ecosystems have
been calculated based on the estimation of the
indirect values of the aquatic ecosystems in
flood control, groundwater recharge, shoreline
stabilization and shore protection, nutrition
cycling and retentions, water purification,
preservation of biodiversity, and recreation and
tourism. Source extracted from the World Water
Development Report. Costanza et al., 1997. 'The
nature of the world's ecosystem services and
natural capital' Nature, Vol. 387, pp. 253-60.
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Water scarcity

• Freshwater and the hydrological cycle
• Water hot spots in the world
• How to deal with water scarcity
• Water pricing/valuation
• XXXX
• Global warming and water scarcity

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Water use efficiency in agriculture
Drip irrigation reduces water use by 30 to 70
percent and increases crop yield by 20 to 90
percent compared with flooding methods
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Partial Root Drying technique
PRD used in grape, lychee- and mangocultivations
in Asia Australia
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Seawater Desalination System Membrane
distillation uses a special membrane to bring out
the water vapor generated from collected
seawater, collecting it as freshwater, and it is
a revolutionary new method different from its
predecessors. This special membrane is a porous
hydrophobic membrane, which means that water
vapor can pass through it, but drops of water
cannot. As shown in the diagram, by passing hot
seawater through one side of the membrane, only
the water vapor generated from the seawater
passes through. The water vapor is then cooled by
the cool water on the other side of the membrane,
forming water drops, resulting in freshwater.
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Reducing urban water consumption
Can technology help? Simple devices like
low-flow toilets can cut usage by 70 percent.
When New York City was faced with spending 1
billion on a new pumping station in the early
1990s, it opted instead to replace toilets. By
1997, after the city spent 295 million on
incentives, 1.33 million new toilets had been
installed, saving 70 million to 90 million
gallons per day. Overall, per capita consumption
dropped from 195 gallons in 1991 to 169 gallons
in 1999. ( 1 gallon 4,55 l).
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Water scarcity

• Freshwater and the hydrological cycle
• Water hot spots in the world
• How to deal with water scarcity
• Water pricing/valuation
• Water saving technologies
• Water Conflict ?

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Water Conflict

• For assignment see Blackboard

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