13-4 Is Transferring Water from One Place to Another the Answer?

1
13-4 Is Transferring Water from One Place to
Another the Answer?

• Concept 13-4 Transferring water from one place
  to another has greatly increased water supplies
  in some areas, but it has also disrupted
  ecosystems.

2
Water Transfers Can Be Wasteful and
Environmentally Harmful

• Using a lot of water to produce a water thirsty
  plant, like ________________, is not necessarily
  a bad thingif the crop is grown in areas with
  ___________ of water
• However, U.S. lettuce primarily comes from
  Californias _____________ Central Valley area,
  and requires the use of heavy _________________

lettuce
a lot
arid
irrigation
3
Southern California Lettuce Grown with
________________ California Water
Northern
Fig. 13-15, p. 331
4
California Transfers Water from Water-Rich Areas
to Water-Poor Areas
transferred

• Water ________________ from north to south by
• Tunnels
• Aqueducts
• Underground pipes
• This water transfer project is called the
  ___________________ ___________ ___________
• ___________________ water use in arid regions
• Environmental damage to _______________ River and
  San Francisco ___________

California
Water
Project
Inefficient
Sacramento
Bay
5
CALIFORNIA
NEVADA
Shasta Lake Oroville Dam and
UTAH
Sacramento River
Reservoir
Feather River
Lake Tahoe
North Bay Aqueduct
Sacramento
SIERRA MOUNTAIN RANGE
San Francisco
South Bay Aqueduct
Hoover Dam and Reservoir (Lake Mead)
Fresno
San Luis Dam and Reservoir
San Joaquin Valley
Colorado River
Los Angeles Aqueduct
California Aqueduct
ARIZONA
Colorado River Aqueduct
Santa Barbara
Central Arizona Project
Los Angeles
Phoenix
Salton Sea
San Diego
Tucson
MEXICO
Fig. 13-16, p. 331
6
California Transfers Water from Water-Rich Areas
to Water-Poor Areas

• Projected climate change may make situation
  worse
• snow packs in the _________ ______________
  mountains may
• melt _________________
• Receive ___________ precipitation during drought
  years
• Some analysts project that during this century,
  many people living in arid, Southern California
  cities, will have to _______________ elsewhere

High
Sierra
faster
less
move
7
Case Study The Aral Sea Disaster (1)

• The ___________ Sea was once the worlds
  _______ largest lake
• 1960 has been used for a large scale water
  transfer to irrigate one of the driest areas in
  central _____________
• Cotton and rice

Aral
4th
Asia
8
Natural Capital Degradation The Aral Sea,
Shrinking Freshwater Lake
Fig. 13-17, p. 332
9
Case Study The Aral Sea Disaster (2)

• The large scale water transfer was also coupled
  with
• _____________________
• High ________________ rates
• Since 1961
• Water levels have dropped by an amount equivalent
  to a _____________ building
• the seas salinity (___________ content) has
  risen _________________________

drought
evaporation
6-story
salt
seven-fold
10
Case Study The Aral Sea Disaster (2)

• 85 of the areas ________________ have been
  eliminated
• ___________ of local bird and mammal species have
  disappeared
• Devastated the areas ______________ industry
• The southern portion of the Aral Sea is now a
  desert covered with glistening white
  _______________

wetlands
Half
fishing
salt
11
Case Study The Aral Sea Disaster (2)

• Wind-blown salt and dust ________________ other
  fields and wildlife areas
• Settling on the __________________ in the
  Himalayas causing them to melt at a ____________
  rate
• To increase yields, farmers are using _________
  herbicides, insecticides, and fertilizers, which
  have percolated into the ___________________

pollutes
glaciers
faster
more
groundwater
12
Case Study The Aral Sea Disaster (2)

• People living in the Aral Sea watershed have
  experienced increasing ___________ problems due
  to all of the pollution
• Anemia
• Respiratory illnesses
• Liver and kidney disease
• Eye problems
• Various cancers

health
13
Case Study The Aral Sea Disaster (2)

• Since 1999, the United Nations and World Bank
  have spent about 600 million to
• _________________ drinking water
• _______________ irrigation and drainage systems
• Neighboring countries have been replacing
  water-thirsty crops with others that require
  ________ irrigation
• ___________ was built to raise lake levels in the
  Northern Aral Sea

purify
improve
less
Dike
14
13-5 Is Converting Salty Seawater to Freshwater
the Answer?

• Concept 13-5 We can convert salty ocean water to
  freshwater, but the cost is high, and the
  resulting salty brine must be disposed of without
  harming aquatic or terrestrial ecosystems.

15
Removing Salt from Seawater Is Costly, Kills
Organisms, Creates Briny Wastewater (1)

• Desalination - removing dissolved salts from
  ocean water or from _____________ (slightly
  salty) water in aquifers or lakes
• Two most widely used methods are ________________
  and _______________ osmosis
• Distillation uses
• heat to evaporate water, leaving salts
  ______________
• Cool or ___________________ steam back into
  liquid water

brackish
distillation
reverse
behind
condense
16
Removing Salt from Seawater Is Costly, Kills
Organisms, Creates Briny Wastewater (1)

• Reverse osmosisalso called _________________
• Uses high ______________ to force salt water
  through a membrane _____________ with pores that
  are small enough to remove the salt
• Currently there are about ________________
  desalination plants mostly in arid areas of
• Middle east
• North Africa
• Caribbean
• Mediterranean

microfiltration
pressure
filter
14,450
17
Removing Salt from Seawater Is Costly, Kills
Organisms, Creates Briny Wastewater (2)

• Three major problems with the widespread use of
  desalination
• High __________ and energy footprint
• Chemicals are required to keep down ___________
  growth____________ many marine organisms
• Produces huge quantities of ____________ salts
  that must go somewhere
• Bottom Line Currently, desalination is
  practical only for water _____________,
  _______________ countries

cost
algal
kill
waste
short
wealthy
18
Science Focus The Search for Improved
Desalination Technology

• Improved desalination?
• Using other forms of energy to power plants
• _____________________
• _____________________
• _____________________
• Using ___________ to carry desalination equipment
  instead of land-based desalination plants
• Use water from depths ______________ where most
  marine organisms live
• The remaining salt or _____________ could be
  carried away from the coast and
  ___________________

solar
wind
ocean waves
ships
below
brine
diluted
19
Review Questions

• What are some disadvantages of transferring
  water?
• What are some disadvantages of using desalination
  methods?

inefficient
Dries other areas (ecological damage)
Pollution
High cost
High energy needs
Chemical use and salt waste