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Water and Water Pollution. Chapter 11. Core Case Study: Water Conflicts. Water shortages in the Middle East Nile River Jordan Basin Tigris and Euphrates Rivers Peacefully solving the problems. Three Major River Basins in the Middle East. Fig. 11-1, p. 227. 11-1 Will We Have Enough Water?.

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core case study water conflicts
Core Case Study: Water Conflicts
  • Water shortages in the Middle East
  • Nile River
  • Jordan Basin
  • Tigris and Euphrates Rivers
  • Peacefully solving the problems
11 1 will we have enough water
11-1 Will We Have Enough Water?
  • Concept 11-1A We are using available freshwater unsustainably by wasting it, polluting it, and charging too little for this irreplaceable natural resource.
  • Concept 11-1B One of every six people do not have sufficient access to clean water, and this situation will almost certainly get worse.
importance and availability of water
Importance and Availability of Water
  • Why is water so important?
  • Earth as a watery world – 71%
  • Freshwater availability – 0.024%
  • Poorly managed resource
  • Hydrologic cycle
  • Water pollution
groundwater
Groundwater
  • Zone of saturation
  • Water table
  • Aquifers
  • Natural recharge
  • Lateral recharge
slide8
Unconfined Aquifer Recharge Area

Evaporation and transpiration

Precipitation

Evaporation

Confined

Recharge

Area

Runoff

Flowing

artesian well

Recharge Unconfined Aquifer

Stream

Well

requiring

a pump

Water

table

Infiltration

Lake

Infiltration

Unconfined aquifer

Less

permeable material such as clay

Confined aquifer

Confining impermeable rock layer

Fig. 11-2, p. 229

surface water
Surface Water
  • Surface runoff
  • Watershed (drainage) basin
  • Reliable runoff – 1/3 of total
  • Runoff use
    • Domestic – 10%
    • Agriculture – 70%
    • Industrial use – 20%
case study freshwater resources in the united states
Case Study: Freshwater Resources in the United States
  • Uneven distribution
  • Contamination
  • Eastern U.S.
  • Western U.S.
  • Groundwater withdrawal – 50%
  • Water hot spots
slide12
Average annual precipitation (centimeters)

81-122

More than 122

Less than 41

41-81

Acute shortage

Shortage

Adequate supply

Metropolitan regions with population greater than 1 million

Stepped Art

Fig. 11-3, p. 230

freshwater shortages
Freshwater Shortages
  • Causes of water scarcity
    • Dry climate
    • Too many people
  • 1 of 6 people – no regular access to clean water
future trends
Future Trends
  • United Nations Report
    • 2-7 billion people will face water shortages by 2050
  • Effect of global warming?
  • Interconnections
    • Food
    • Economics
    • Social
11 2 how can we increase water supplies
11-2 How Can We Increase Water Supplies?
  • Concept 11-2A Groundwater used to supply cities and grow food is being pumped from aquifers in some areas faster than it is renewed by precipitation.
  • Concept 11-2B Using dams, reservoirs, and transport systems to transfer water to arid regions has increased water supplies in those areas, but has disrupted ecosystems and displaced people.
11 2 how can we increase water supplies18
11-2 How Can We Increase Water Supplies?
  • Concept 11-2C 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.
increasing freshwater supplies
Increasing Freshwater Supplies
  • Withdrawing groundwater
  • Dams and reservoirs
  • Transporting surface water
  • Desalination
  • Water conservation
  • Better use of natural hydrologic cycle
slide24
Major

irrigation

well

Well contaminated

with saltwater

Water

table

Sea level

Saltwater

Fresh

groundwater

aquifer

Seafloor

Interface

Saltwater

intrusion

Interface

Normal

interface

Fig. 11-9, p. 234

groundwater depletion
Groundwater Depletion

Fig. 11-10, p. 234

slide28
Provides

irrigation water

above and

below dam

Flooded land

destroys forests

or cropland and

displaces people

Large losses of

water through

evaporation

Provides water

for drinking

Deprives

downstream

cropland and

estuaries of

nutrient-rich silt

Reservoir useful

for recreation

and fishing

Risk of failure

and devastating

downstream

flooding

Can produce

cheap electricity

(hydropower)

Reduces

downstream

flooding

Disrpupts

migration and

spawning of

some fish

Fig. 11-11a, p. 235

slide30
Powerlines

Reservoir

Dam

Powerhouse

Intake

Turbine

Fig. 11-11b, p. 235

aral sea disaster 1
Aral Sea Disaster (1)
  • Large-scale water transfers in dry central Asia
  • Salinity
  • Wetland destruction and wildlife
  • Fish extinctions and fishing
aral sea disaster 2
Aral Sea Disaster (2)
  • Wind-blown salt
  • Water pollution
  • Climatic changes
  • Restoration efforts
shrinking aral sea
Shrinking Aral Sea

Fig. 11-14, p. 237

removing salt from seawater
Removing Salt from Seawater
  • Desalination
  • Distillation
  • Reverse osmosis
  • 15,000 plants in 125 countries
major problems with desalination
Major Problems with Desalination
  • High cost
  • Death of marine organisms
  • Large quantity of brine wastes
  • Future economics
11 3 how can we use water more sustainably
11-3 How Can We Use Water More Sustainably?
  • Concept 11-3 We can use water more sustainably by cutting water waste, raising water prices, slowing population growth, and protecting aquifers, forests, and other ecosystems that store and release water.
reducing water waste 1
Reducing Water Waste (1)
  • Benefits of water conservation
  • Worldwide – 65-70% loss
    • Evaporation, leaks
  • Water prices, government subsides, waste
reducing water waste 2
Reducing Water Waste (2)
  • Improve irrigation efficiency
  • Improve collection efficiency
  • Use less in homes and businesses
slide42
Center pivot

(efficiency 80% with low-pressure

sprinkler and 90–95% with LEPA sprinkler)

Drip irrigation

(efficiency 90–95%)

Gravity flow

(efficiency 60% and 80% with surge valves)

Water usually pumped from underground and sprayed from mobile

boom with sprinklers.

Above- or below-ground pipes or tubes deliver water to individual plant roots.

Water usually comes from an aqueduct system or a nearby river.

Fig. 11-15, p. 240

reducing water waste
Reducing Water Waste

Fig. 11-17, p. 241

sustainable water use
Sustainable Water Use

Fig. 11-18, p. 242

what can you do
What Can You Do?

Fig. 11-19, p. 242

11 4 how can we reduce the threat of flooding
11-4 How Can We Reduce the Threat of Flooding?
  • Concept 11-4 We can improve flood control by protecting more wetlands and natural vegetation in watersheds and by not building in areas subject to frequent flooding.
benefits of floodplains 1
Benefits of Floodplains (1)
  • Highly productive wetlands
  • Provide natural flood and erosion control
  • Maintain high water quality
  • Recharge groundwater
benefits of floodplains 2
Benefits of Floodplains (2)
  • Fertile soils
  • Nearby rivers for use and recreation
  • Flatlands for urbanization and farming
dangers of floodplains and floods
Dangers of Floodplains and Floods
  • Deadly and destructive
  • Human activities worsen floods
  • Failing dams and water diversion
  • Hurricane Katrina and the Gulf Coast
    • Removal of coastal wetlands
case study floodplains of bangladesh
Case Study: Floodplains of Bangladesh
  • Dense population
  • Located on coastal floodplain
  • Moderate floods maintain fertile soil
  • Increase frequency of large floods
  • Development in the Himalayan foothills
  • Destruction of coastal wetlands
slide55
Oxygen

released by

vegetation

Diverse

ecological

habitat

Evapotranspiration

Trees reduce soil

erosion from heavy

rain and wind

Agricultural

land

Tree roots stabilize soil

Vegetation releases water

slowly and reduces flooding

Forested Hillside

Fig. 11-21a, p. 244

slide57
Tree plantation

Evapotranspiration decreases

Roads

destabilize

hillsides

Overgrazing accelerates soil

erosion by water and wind

Winds remove

fragile topsoil

Agricultural land

is flooded and

silted up

Gullies and

landslides

Heavy rain erodes topsoil

Silt from erosion fills rivers and reservoirs

Rapid runoff

causes flooding

After Deforestation

Fig. 11-21b, p. 244

reducing flood damage
Reducing Flood Damage

Fig. 11-22, p. 245

11 5 how can we best deal with water pollution 1
11-5 How Can We Best Deal with Water Pollution? (1)
  • Concept 11-5A Streams can cleanse themselves of many pollutants if we do not overload them.
  • Concept 11-5B Preventing water pollution usually works better and costs less than trying to clean it up.
11 5 how can we best deal with water pollution 2
11-5 How Can We Best Deal with Water Pollution? (2)
  • Concept 11-5C Reducing water pollution requires preventing it, working with nature in treating sewage, cutting resource use and waste, reducing poverty, and slowing population growth.
water pollution sources
Water Pollution Sources
  • Water pollution
  • Point sources
    • Discharge at specific locations
    • Easier to identify, monitor, regulate
  • Nonpoint sources
    • Runoff of chemicals and sediment
    • Agriculture
    • Control is difficult and expensive
stream pollution
Stream Pollution
  • Natural recovery processes
  • Oxygen sag curve
  • Effect of regulations in the U.S.
  • Continuing problems
  • Problems in developing countries
slide65
Normal clean water organisms(Trout, perch, bass,mayfly, stonefly)

Trash fish (carp, gar,

leeches)

Fish absent, fungi, sludge

worms,

bacteria (anaerobic)

Trash fish (carp, gar,

leeches)

Normal clean water organisms

(Trout, perch, bass,

mayfly, stonefly)

8 ppm

Types of organisms

8 ppm

Dissolved oxygen (ppm)

Clean Zone

Biological

oxygen demand

Recovery Zone

Septic Zone

Decomposition Zone

Clean Zone

Fig. 11-23, p. 247

lake pollution 1
Lake Pollution (1)
  • Dilution less effective than with streams
    • Stratification
    • Low flow
  • Lakes are more vulnerable than streams
  • Eutrophication – natural aging process
    • Oligotrophic
lake pollution 2
Lake Pollution (2)
  • Cultural eutrophication
    • Cause
    • Prevention
    • Cleanup
groundwater pollution 1
Groundwater Pollution (1)
  • Sources
  • Slow flow, dilution, dispersion
  • Low dissolved oxygen
  • Fewer bacteria
  • Cooler temperatures
groundwater pollution 2
Groundwater Pollution (2)
  • Longtime scale for natural cleansing
    • Degradable wastes – organic matter
    • Slowly degradable wastes – DDT
    • Nondegradable wastes – lead, arsenic, fluoride
slide72
Polluted air

Hazardous waste

injection well

Pesticides

and fertilizers

Deicing

road salt

Coal strip

mine runoff

Buried gasoline

and solvent tanks

Cesspool,

septic tank

Gasoline station

Pumping

well

Water

pumping well

Waste lagoon

Sewer

Landfill

Leakage

from faulty

casing

Accidental

spills

Discharge

Confined

aquifer

Unconfined freshwater aquifer

Groundwater

flow

Confined freshwater aquifer

Fig. 11-25, p. 249

extent of groundwater pollution
Extent of Groundwater Pollution
  • Global scale – not much known
  • Monitoring is very expensive
  • Underground fuel tank leakage
    • MTBE
  • Arsenic
  • Protecting groundwater – prevention is best!
ocean pollution
Ocean Pollution
  • Coastal areas – highly productive ecosystems
    • Occupied by 40% of population
    • Twice that population by 2050
    • About 80% marine pollution originates on land
  • Deep ocean waters
    • Some capacity to dilute, disperse, degrade pollutants
    • Ocean dumping controversies
    • Assimilative capacity?
slide77
Industry

Nitrogen oxides

from autos and

smokestacks,

toxic chemicals,

and heavy metals in

effluents flow into

bays and estuaries.

Cities

Toxic metals and

oil from streets and

parking lots pollute

waters; sewage

adds nitrogen and

phosphorus.

Urban sprawl

Bacteria and viruses from

sewers and septic tanks

contaminate shellfish beds

and close beaches; runoff of

fertilizer from lawns adds

nitrogen and phosphorus.

Construction sites

Sediments are washed into

waterways, choking fish and plants,

clouding waters, and blocking sunlight.

Farms

Runoff of pesticides, manure, and

fertilizers adds toxins and excess

nitrogen and phosphorus.

Red tides

Excess nitrogen causes

explosive growth of toxic

microscopic algae,

poisoning fish and

marine mammals.

Closed

shellfish beds

Closed

beach

Oxygen-depleted

zone

Toxic sediments

Chemicals and toxic metals

contaminate shellfish beds,

kill spawning fish, and

accumulate in the tissues

of bottom feeders.

Oxygen-depleted zone

Sedimentation and algae

overgrowth reduce sunlight,

kill beneficial sea grasses, use

up oxygen, and degrade habitat.

Healthy zone

Clear, oxygen-rich

waters promote growth

of plankton and sea

grasses,and support fish.

Fig. 11-27, p. 251

slide79
Missouri River

Mississippi

River Basin

Ohio River

Mississippi River

Depleted oxygen

Stepped Art

Fig. 11-A, p. 252

case study chesapeake bay
Case Study: Chesapeake Bay
  • Largest estuary in the U.S.
  • Large drainage basin
    • Pollution sink
  • Cultural eutrophication
    • Oxygen depletion
  • Chesapeake Bay Program
oil pollution in oceans
Oil Pollution in Oceans
  • Crude and refined petroleum
  • Tanker accidents – Exxon Valdez
  • Urban and industrial runoff
effects of oil pollution on ocean ecosystems
Effects of Oil Pollution on Ocean Ecosystems
  • Volatile organic hydrocarbons
    • Kill larvae
    • Destroys natural insulation and buoyancy
  • Heavy oil
    • Sinks and kills bottom organisms
    • Coral reefs die
oil cleanup methods
Oil Cleanup Methods
  • Current methods recover no more than 15%
  • Prevention is most effective method
    • Control runoff
    • Double haul tankers
preventing nonpoint source pollution 1
Preventing Nonpoint Source Pollution (1)
  • Mostly agricultural waste
  • Use vegetation to reduce soil erosion
  • Reduce fertilizer use
preventing nonpoint source pollution 2
Preventing Nonpoint Source Pollution (2)
  • Use plant buffer zones around fields and animal feedlots
  • Keep feedlots away from slopes, surface water and flood zones
  • Integrated pest management
laws for reducing point source pollution
Laws for Reducing Point Source Pollution
  • Clean Water Act
  • Water Quality Act
  • Discharge trading controversies
sewage treatment systems
Sewage Treatment Systems
  • Rural and suburban areas – septic tank
  • Urban areas – wastewater treatment plants
    • Primary treatment – physical process
    • Secondary treatment – biological process
    • Chlorination – bleaching and disinfection
slide90
Primary

Secondary

Chlorine

disinfection tank

Bar screen

Grit chamber

Settling tank

Aeration tank

Settling tank

To river, lake,

or ocean

Sludge

Raw sewage

from sewers

(kills bacteria)

Activated sludge

Air pump

Disposed of in

landfill or ocean or applied to cropland,

pasture, or rangeland

Sludge digester

Sludge drying bed

Fig. 11-29, p. 255

improving sewage treatment
Improving Sewage Treatment
  • Systems that exclude hazardous waste
  • Nonhazardous waste substitutes
  • Composting toilet systems
science focus ecological wastewater treatment
Science Focus: Ecological Wastewater Treatment
  • Working with nature to treat sewage
  • Living machines
  • Tanks with increasingly complex organisms
  • Artificially created wetlands
  • Scientific principles of sustainability
reducing water pollution from point sources in the u s
Reducing Water Pollution from Point Sources in the U.S.
  • Impressive achievements
  • Bad news – 2006 survey
    • 45% of lakes and 40% of streams too polluted for fishing and swimming
    • Runoff polluting 7 of 10 rivers
    • Fish caught in 1/4 of waterways unsafe to eat
should the clean water act be strengthened
Should the Clean Water Act be Strengthened?
  • Yes – environmentalists
  • No – farmers and developers
  • State and local officials want more discretion
drinking water quality
Drinking Water Quality
  • Purification of urban drinking water
  • Developed versus developing countries
is bottled water the answer
Is Bottled Water the Answer?
  • 120 to 7,500 times the cost of tap water
  • About 1/4 is ordinary tap water
  • About 40% of bottled water contaminated
  • Water testing
  • Water purifiers
what can we do
What Can We Do?

Fig. 11-31, p. 258

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