Water%20Resources

1
Water Resources

• Chapter 13

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Water Conflicts in the Middle East

• Water shortages in the Middle East hydrological
  poverty
• Nile River flows through 7 countries for
  irrigation and drinking water. Ethiopia, Sudan,
  Egypt.
• Jordan Basin most water short,
• Tigris and Euphrates Rivers Turkey
• Conflicts will increase among nations that share
  water resources

Three Major River Basins in the Middle East
3
Freshwater Is an Irreplaceable Resource

• Covers 71 of the earths surface
• Water sculpts the earths surface
• Moderates climate
• Removes, dilutes pollutants and wastes
• --------------------------------------------------
  -------------
• Poorly managed resource
• waste and pollute
• charge too little to make it available

4
Water is an irreplaceable resource

• Global health issue lack of safe drinking water
  and sanitation is the worlds single largest
  cause of illness
• 2007 WHO 1.6 million 90 of them under 5
  die from waterborne diseases diarrhea, typhoid,
  hepatitis
• Economic Issue vital for reducing poverty
• Developing countries women and childrens issue
• National and global security issue increasing
  tensions within and between nations over shared
  resources
• Environmental issue excessive withdrawal of
  water from rivers and aquifers lowers water
  tables, lower river flows, shrinking lakes,
  reduce fish populations, species extinction,
  degradation of ecosystem services.

5
Girl Carrying Well Water over Dried Out Earth
during a Severe Drought
6
Most of the Earths Freshwater Is Not Available
to Us

• About 0.024 available as liquid water in
  groundwater deposits, lakes, rivers, and streams
• Rest in salty oceans, frozen in polar ice caps
  and glaciers, deep underground
• Hydrologic cycle
• Movement of water in the seas, land, and air
• Driven by solar energy and gravity
• People divided into
• Water haves
• Water have-nots

7
We Get Freshwater from Groundwater and Surface
Water

• Ground water precipitation filters downwards
  through spaces in soil, gravel and rock until a
  layer of rock stops it
• Zone of saturation spaces in soil and rock
  close to the earths surface are completely
  filled with water
• Water table top of the ground water zone, falls
  in dry weather or when ground water removed too
  fast
• Aquifers underground caverns and porous layers
  of sand, gravel or bedrock through which ground
  water flows, large elongated sponges, moves 1
  meter/year
• Natural recharge downward percolation through
  soil and rock
• Lateral recharge from nearby rivers and streams

8
We Get Freshwater from Groundwater and Surface
Water

• Surface Water freshwater from precipitation and
  snow melt flows across land surface into rivers,
  streams, lakes, wetlands
• Surface runoff - precipitation does not
  infiltrate into the ground or returns to
  atmosphere by evaporation
• Watershed (drainage) basin land from which
  surface water drains into a specific body of
  water
• Reliable runoff amount of surface run off that
  we can count on as a source of fresh water from
  year to year
• 1/3 of total

9
Groundwater Unconfined and Confined Aquifer
Unconfined Aquifer Recharge Area
Evaporation and transpiration
Evaporation
Precipitation
Confined Recharge Area
Runoff
Flowing artesian well
Well requiring a pump
Stream
Water table
Infiltration
Lake
Infiltration
Unconfined aquifer
Less permeable material such as clay
Confined aquifer
Confining impermeable rock layer
Fig. 13-3, p. 316
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Large and Growing Portion of the Worlds Reliable
Runoff Used

• 2/3 of the surface runoff lost by seasonal
  floods
• 1/3 runoff usable 34 withdrawn now, 70 by
  2025 to support increased population growth
• Domestic 10
• Agriculture 70
• Industrial use 20

11
Fred Pearce When Rivers Run Dry

• 450,000 liters(120 000 gallons) produce small
  car
• 140 liters (37 gallons) produce a cup of coffee
• 25 bath tubs full of water to produce ONE T-shirt

12
Freshwater Resources in the US

• More than enough renewable freshwater, unevenly
  distributed
• Contaminated by agriculture, industry
• Effect of
• Floods
• Pollution
• Drought
• 2007 U.S. Geological Survey projection
• Water hotspots

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Water Hotspots in 17 Western U.S. States
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Fig. 13-4a, p. 317
15
water deficit regions
Fig. 13-4b, p. 317
16
Water Shortages Will Grow..

• Dry climate
• Drought
• Too many people using a normal supply of water
• More than 30 countries in the Middle East and
  Africa

Stress on the Worlds Major River Basins
17
Water Shortages Will Grow.

• Wasteful use of water
• China and urbanization 2/3rd of the country face
  water shortages
• Hydrological poverty- 1.1 billion people

Stress on the Worlds Major River Basins
18
Long-Term Severe Drought Is Increasing

• Causes
• Extended period of below-normal rainfall
• Diminished groundwater due to falling water
  tables, climate change, severe drought
• Harmful environmental effects
• Dries out soils
• Reduces stream flows
• Decreases tree growth and biomass
• Lowers net primary productivity and crop yields
• Shift in biomes toward relatively dry conditions
  such savannas and deserts

19
In Water-Short Areas Farmers and Cities Compete
for Water Resources

• 2007 National Academy of Science study
• Increased corn production in the U.S. to make
  ethanol as an alternative fuel
• Decreasing water supplies
• Aquifer depletion
• Increase in pollution of streams and aquifers

Other crops soybeans, oil palms, sugar cane
20
Managing Freshwater Resources.

• Most water resources
• Owned by governments
• Managed as publicly owned resources
• Veolia and Suez French companies water
  scarcity ,worlds most urgent environmental
  problem
• Buy and manage water resources lucrative
• Veolia water for 108 million in 57 countries
• Successful outcomes in many areas

21
Managing Freshwater Resources.

• Bechtel Corporation
• Poor water management in Bolivia -2002
• A subsidiary of Bechtel Corporation - 2007
• Poor water management in Ecuador
• Potential problems with full privatization of
  water resources
• Financial incentive to sell water not conserve
  it
• Poor will still be left out

22
Is Extracting Groundwater the Answer ?

• Groundwater that is used to supply cities and
  grow food is being pumped from aquifers in some
  areas faster than it is renewed by precipitation.
  
• Aquifers provide drinking water, 37 of
  irrigation water

23
Water Tables Fall When Groundwater Is Withdrawn
Faster Than It Is Replenished

• India, China, and the United States
• Three largest grain producers
• Over pumping aquifers for irrigation of crops
• half a billion people
• India and China
• Small farmers drilling tube wells
• Effect on water table falls
• Increasing demands for electricity-coal fired
  plants
• Saudi Arabia
• 70 of its drinking water at a high
  cost-salinization
• Deep Aquifer depletion and irrigation ( estimated
  to disappear within 1 to 2 decades)

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Irrigation in Saudi Arabia Using an Aquifer
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TRADE-OFFS
Withdrawing Groundwater
Advantages
Disadvantages
Useful for drinking and irrigation
Aquifer depletion from overpumping
Sinking of land (subsidence) from overpumping
Available year-round
Aquifers polluted for decades or centuries
Exists almost everywhere
Saltwater intrusion into drinking water supplies
near coastal areas
Renewable if not overpumped or contaminated
Reduced water flows into surface waters
No evaporation losses
Increased cost and contamination from deeper wells
Cheaper to extract than most surface waters
Fig. 13-7, p. 321
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Areas of Greatest Aquifer Depletion in the U.S.
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Aquifer Depletion in the United States

• Ogallala aquifer largest known aquifer- lies
  under 8 mid western states from South Dakota to
  Texas
• Irrigates the Great Plains
• Water table lowered more than 30m
• Cost of high pumping makes it too expensive to
  irrigate in certain areas. Amount of farmland
  decreased by 11
• Government subsidies to continue farming deplete
  the aquifer further by encouraging the growth of
  water thirsty crops
• Biodiversity threatened in some areas
• California Central Valley serious water
  depletion

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SOUTH DAKOTA
WYOMING
Ogallala - Worlds Largest Known Aquifer
NEBRASKA
COLORADO
KANSAS
OKLAHOMA
NEW MEXICO
Miles
TEXAS
0
100
160
0
Kilometers
Saturated thickness of Ogallala Aquifer
Less than 61 meters (200 ft.)
61183 meters (200600 ft.)
More than 183 meters (600 ft.) (as much as 370
meters or 1,200 ft. in places)
Fig. 13-10, p. 323
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Groundwater Over pumping Has Other Harmful
Effects

• Limits future food production
• Bigger gap between the rich and the poor
  expensive to dig deeper wells, buy large pumps
  and use more electricity to drive the pumps. Poor
  farmers cannot afford to do this, give up farming
  and migrate to cities
• Land subsidence with drawing large amounts of
  water causes the sand and rocks in aquifers to
  collapse
• Mexico City sunk 10 meters, Beijing, Bangkok
• US San Joaquin Valley, Baton Rouge, Phoenix
• Sinkholes large craters that form when the roof
  of an underground cavern collapses when
  groundwater drained. Can appear suddenly

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SOLUTIONS
Groundwater Depletion
Prevention
Control
Waste less water
Raise price of water to discourage waste
Subsidize water conservation
Tax water pumped from wells near surface waters
Limit number of wells
Set and enforce minimum stream flow levels
Do not grow water-intensive crops in dry areas
Divert surface water in wet years to recharge
aquifers
Fig. 13-11, p. 324
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Harmful Effects of Groundwater Over pumping

• Groundwater overdrafts near coastal regions
• Salt Water Intrusion - Contamination of the
  groundwater with saltwater
• Undrinkable and unusable for irrigation
• Serious coastal areas of Florida, California,
  South Carolina, Georgia, New Jersey , Texas
• Turkey, Manila, Philippines, Bangkok

Rising sea levels from global warming will
increase salt water intrusion and decrease the
amount of ground water available
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Are Deep Aquifers the Answer?

• Locate the deep aquifers determine if they
  contain freshwater or saline water.
• Drill a bore hole and measure the electrical
  resistance of layers of geological material at
  different depths. Freshwater aquifers has higher
  electrical resistance than saline
• Measurements of the natural radioactive
  emissions of gamma rays locates aquifers
• Major concerns
• Geological and ecological impact of pumping water
  from them
• Flow beneath more than one country
• Who has rights to it?

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Role of Large Dams and Reservoirs ..

• Main goals of a dam and reservoir system
• Capture and store runoff
• Release runoff as needed to control
• Floods
• Generate electricity
• Supply irrigation water
• Recreation (reservoirs)

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Advantages and Disadvantages of large dams and
reservoirs

• Disadvantages
• 1.Displaces people
• 40-80 million people
• 2.Flooded regions
• 3.Impaired ecological services of rivers
• 4.Loss of plant and animal species
• 5.Fill up with sediment within 50 years

Advantages 1.Increase available
reliable run off 2. Reduce flooding 3.
Grow crops in arid regions 4.
Produce energy
800,000 dams world wide 45,000 large dams 22,000
in China
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The Ataturk Dam Project in Eastern Turkey on the
River Euphrates
1999
1976
36
Some Rivers Are Running Dry and Some Lakes Are
Shrinking

• Dams disrupt the hydrologic cycle
• reduce downtown flow to a trickle
• prevent river water from reaching the sea
• only 21 of the 177 rivers run freely to sea from
  source
• Major rivers running dry part of the year
• Colorado and Rio Grande, U.S.
• Yangtze and Yellow, China
• Indus, India
• Danube, Europe
• Nile River-Lake Victoria, Egypt
• Lake Chad, Africa disappearing shrunk 96 since
  1960

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The Colorado River Basin An Over tapped Resource

• 2,300 km through 7 U.S. states
• From snow melt in the Rocky Mountains
• 14 Dams and reservoirs
• Located in a desert area within the rain shadow
  of the Rocky Mountains

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The Colorado River Basin An Over tapped Resource

• Supplies water and electricity for more than 25
  million people
• Las Vegas ,San Diego, LA, Californias Imperial
  Valley
• Irrigation 15 of the nations crops and
  livestock
• Recreation

39
The Colorado River Basin An Over tapped Resource

• Four Major problems
• Colorado River basin has very dry lands
• Modest flow of water for its size
• Legal pacts allocated more water for human use
  than it can supply
• Amount of water flowing to the mouth of the river
  has dropped

40
Aerial View of Glen Canyon Dam Across the
Colorado River and Lake Powell

• Economic and ecological catastrophe
• Political and legal battle over who will get how
  much of the regions diminished water supply
• Agricultural production would drop sharply

41
Chinas Three Gorges Dam

• Worlds largest hydroelectric dam, built across
  the Yangtze
• 2 km long, built at a cost of 25 billion
• Produce enough power for 22 large coal-burning
  power plants. Reduce Chinas dependence on coal
  and cut down greenhouse gas emissions
• Hold back the flood waters of the Yangtze which
  have killed more than 500,000 in the past 100
  years
• Large cargo carrying ships to travel into Chinas
  interior
• 600 km reservoir behind the dam

42
Chinas Three Gorges Dam

• Harmful effects
• Displaces about 5.4 million people
• Built over a seismic fault
• Significance?
• Rotting plant and animal matter producing CH4
• Worse than CO2 emissions
• Will the Yangtze River become a sewer?

43
Is Transferring Water from One Place to Another
the Answer?

• Water transferred by
• Tunnels
• Aqueducts
• Underground pipes
• California Water Project
• from water rich North to south
• contention over water rights

44
The Aral Sea Disaster

• Large-scale water transfers in dry central Asia
• 1960 on water diverted to 2 feeder rivers to
  create one of the worlds largest irrigation
  areas- cotton, rice
• Salinity risen 7 fold, average water dropped by
  22 meters
• Lost 89 of water volume
• Wetland destruction (85), wildlife(50) gone
• Fish extinctions and fishing 28 of 32 species
  gone

45
The Aral Sea Disaster

• Wind-blown salt up to 500 km away
• Aral sea dust settling on glaciers in the
  Himalayas, causing them to melt at faster rate
• Water pollution salt spreads, kills fish
• Climatic changes no thermal buffer, because sea
  has shrunk
• Restoration efforts

46
Ship Stranded in Desert Formed by Shrinkage of
the Aral Sea
47
China Plans a Massive Transfer of Water

• South-North Water Transfer Project
• Water from three rivers to supply 0.5 billion
  people
• Completion in about 2050
• Impact
• Economic
• Health
• Environmental

48
Is Converting Salty Seawater to Freshwater the
Answer?

• Desalination involves removing dissolved salts
  from ocean water/brackish water
• Converting salty ocean water to freshwater
• The cost is high, and the resulting salty brine
  must be disposed of without harming aquatic or
  terrestrial ecosystems.

49
Removing Salt from Seawater Promising but
Costly

• Desalination
• Distillation heating saltwater until it
  evaporates, leaving behind salts in solid form
  and condenses as fresh water
• Reverse osmosis, microfiltration high pressure
  forces salt water through a membrane filter with
  pores small enough to remove the salt
• 15,000 plants in 125 countries
• Saudi Arabia highest number

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Removing Salt from Seawater Promising but Costly

• Problems
• High cost and energy footprint desalination
  requires ten times more energy than reverse
  osmosis
• Pumping large volumes of sea water through pipes
  and using chemicals to sterilize the water keeps
  down algal growth and kills many marine organisms
• Large quantity of brine wastes that contain lots
  of salts and other minerals
• Dumping this brine into nearby coastal waters
  increases salinity -threatens aquatic life.
• Disposing on land contaminates ground and
  surface water
• Future economics water short, wealthy countries

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Improved Desalination Technology

• Desalination on offshore ships
• Solar or wind energy to desalinate water cheaply
• Energetech,H2AU (Australia) energy from ocean
  waves drive reverse osmosis
• 2005 GE developing technology
• Better membranes more efficient separation ,
  less pressure, less energy
• Develop molecular size nanofilters
• Better disposal options for the brine waste
• Reduce water needs, conserve water

52
Use Water More Sustainably

• 65-70 water people use wasted through
  evaporation , leaks
• Main reason for water waste low cost to users,
  government subsidies
• False message that water is abundant
• Use water more sustainably by cutting water waste
  to 15, raising water prices, slowing population
  growth, and protecting aquifers, forests, and
  other ecosystems that store and release water.
• Life line rates South Africa
• Lack of government subsidies

53
Cut water waste in irrigation .

• Flood irrigation method delivers far more water
  than is needed for crop growth and typically
  loses 40 of the water through evaporation,
  seepage, and run off. This wasteful method is
  used on 97 of Chinas irrigated land
• More efficient and environmentally sound
  irrigation technologies can greatly reduce water
  waste on farms

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Irrigation Systems

• Flood irrigation
• Wasteful
• Center pivot, low pressure sprinkler
• Low-energy, precision application sprinklers
• Drip or trickle irrigation, micro irrigation
• Costly less water waste

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Developing Countries Use Low-Tech Methods for
Irrigation

• Human-powered treadle pumps to pump groundwater
  through irrigation ditches in Bangladesh
• Harvest and store rainwater running pipes from
  roof tops, digging channels to catch rain water
  and stored India
• Polyculture and agroforesstry to create a canopy
  over crops reduces evaporation
• Plant deep rooted perennial crop varieties ,
  control weeds, and mulch fields
• Fog-catcher nets developed in Chile are used to
  harvest water

59
Cut Water Waste in Industry and Homes

• Recycle water in industry 90 of water used by
  industry
• Raise water prices
• Fix leaks in the plumbing systems stop 10-30
  loss
• Use low flush toilets , low flow shower heads
• Use water-thrifty landscaping xeriscaping
• Use gray water irrigate lawns, non-edible plants
• Singapore all sewage water is treated at
  reclamation plants for reuse by industry
• Pay-as-you-go water use

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Use Less Water to Remove Wastes

• Can we mimic how nature deals with waste?
• Return the nutrient rich sludge produced by
  conventional waste treatment plants to the soil
  as fertilizer, instead of dumping the plant
  nutrients extracted from waste water treatment
  plants into water systems
• Banning the discharge of industrial toxic
  chemicals into sewage treatment plants would help
  to make this feasible
• Waterless composting toilets that convert human
  fecal matter to a small amount of dry and
  odorless soil-like humus material that can be
  removed from a composting chamber every year or so

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Use Water More Sustainably ..

• The frog does not drink up the pond in which it
  lives
• Blue revolution use less water and cut out
  water waste to reduce water footprint

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Reduce the Threat of flooding ..

• We can lessen the threat of flooding by
  protecting more wetlands and natural vegetation
  in watersheds and by not building in areas
  subject to frequent flooding.

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Some Areas Get Too Much Water from Flooding

• Flood plains water in a stream overflows its
  normal channel and spills into an adjacent area
• Highly productive wetlands
• Provide natural flood and erosion control
• Maintain high water quality
• Recharge groundwater
• Benefits of floodplains
• Fertile soils
• Ample water for irrigation
• Nearby rivers for use and recreation
• Flatlands for urbanization and farming

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Some Areas Get Too Much Water from Flooding

• Floodplain - water in a stream overflows its
  normal channel and spills into an adjacent area
• Include highly productive wetlands, provide
  natural flood and erosion control, maintain high
  water quality
• Advantages fertile soil, ample water for
  irrigation, flatland suitable for crops , rivers
  for transportation
• Disadvantages floods kill people and damage
  property
• Removal of water-absorbing vegetation
• Draining and building on wetlands

August 2005 Hurricane Katrina damage
intensified because of removal of coastal
wetlands, lost buffer
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Hillside Before and After Deforestation
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Living Dangerously on Floodplains in Bangladesh

• Dense population -147 million people (size of
  Wisconsin)
• Located on coastal floodplain - slightly above
  sea level
• Moderate floods maintain fertile soil rice,
  thatched roofs
• Increased frequency of large floods every 50
  years,
• Effects of development in the Himalayan foothills
• monsoon rains now run more quickly
• carry vital topsoil with them
• Destruction of coastal wetlands for fuel wood,
  farming and aquaculture
• Result severe flooding from surges

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Reduce Flood Risks..

• Rely more on natures systems
• Wetlands
• Natural vegetation in watersheds
• Preserve wetlands and restore ones that have been
  damaged
• Rely less on engineering devices
• Dams
• Levees
• Increased possibility of flooding downstream

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SOLUTIONS
Reducing Flood Damage
Prevention
Control
Preserve forests on watersheds
Straighten and deepen streams (channelization)
Preserve and restore wetlands in floodplains
Build levees or floodwalls along streams
Tax development on floodplains
Use floodplains primarily for recharging
aquifers, sustainable agriculture and forestry
Build dams
Fig. 13-26, p. 340