Let’s Review Let’s Review 1. 1. Which of the following is most likely Which of the following is most likely to be the direct result of lack of to be the direct result of lack of genetic diversity in a food crop such genetic diversity in a food crop such as corn? as corn? a. a. Decreased kernel size Decreased kernel size b. b. Decreased potential yield Decreased potential yield c. c. Decreased dependence on chemical Decreased dependence on chemical fertilizers fertilizers d. d. Increase susceptibility to plant Increase susceptibility to plant disease. disease.
Transcript
Let’s ReviewLet’s Review1.1. Which of the following is most likely to Which of the following is most likely to
be the direct result of lack of genetic be the direct result of lack of genetic diversity in a food crop such as corn?diversity in a food crop such as corn?
c.c. Decreased dependence on chemical Decreased dependence on chemical fertilizersfertilizers
d.d. Increase susceptibility to plant Increase susceptibility to plant disease.disease.
Let’s try one more…Let’s try one more…
2. 2. Which of the following describes a fundamental Which of the following describes a fundamental characteristic of the Green Revolution in food characteristic of the Green Revolution in food resources?resources?
a.a.The application of higher levels of organic fertilizers to The application of higher levels of organic fertilizers to increase rice productionincrease rice production
b.b.Deforestation to provide field crops with increase Deforestation to provide field crops with increase sunlight for photosynthesissunlight for photosynthesis
c.c.The addition of calorie, fat, and fiber percentages to The addition of calorie, fat, and fiber percentages to the information provided on food package labels.the information provided on food package labels.
d.d.The development of new strains of crops with higher The development of new strains of crops with higher yields.yields.
Water ResourcesWater Resources
Chapter 13Chapter 13
Warm-upWarm-up
• Given that there is a fixed amount of Given that there is a fixed amount of fresh water on the planet, what will fresh water on the planet, what will happen to the distribution of water happen to the distribution of water resources as global population grows?resources as global population grows?
• What happens when a fresh water What happens when a fresh water resource is polluted? resource is polluted?
• Why is it important to protect fresh Why is it important to protect fresh water resources from pollution?water resources from pollution?
Why Is Water Important?Why Is Water Important?
• Water covers ¾ of Earth’s surfaceWater covers ¾ of Earth’s surface
• It has helped shape the continentsIt has helped shape the continents
• It moderates our climateIt moderates our climate
• It allows organisms to survive – It allows organisms to survive – humans are composed of about 70% humans are composed of about 70% water by body weightwater by body weight
Distribution of WaterDistribution of Water
• Seawater 97.5%Seawater 97.5%
• Fresh water 2.5%Fresh water 2.5%•Ice caps and glaciers 1.97%Ice caps and glaciers 1.97%
•Groundwater 0.5%Groundwater 0.5%
•Other water (lakes, rivers, soil, Other water (lakes, rivers, soil, moisture, atmosphere ) 0.03%moisture, atmosphere ) 0.03%
Supply of Water ResourcesSupply of Water Resources
• Drip or trickle Drip or trickle irrigationirrigation
• XeriscapeXeriscape
• Reclaimed WaterReclaimed Water
• Potable WaterPotable Water
Water FactsWater Facts
Every day more than 1 billion people make a 83-hour journey on foot just to collect water.
More than 1.2 billion people (25% of the world’s total population) do not have access to a safe and adequate water supply.
Water FactsWater Facts
• 14,000 people die every day from water-14,000 people die every day from water-related illnesses. This includes diseases related illnesses. This includes diseases transmitted via water such as giardia and transmitted via water such as giardia and dysentery, from lack of water (dehydration), dysentery, from lack of water (dehydration), and from parasites that breed in water (e.g. and from parasites that breed in water (e.g. malaria)malaria)
• An average U.S. citizen will spend 0.5% of An average U.S. citizen will spend 0.5% of his/her annual income on water; while a citizen his/her annual income on water; while a citizen of Honduras will spend 25% of his/her annual of Honduras will spend 25% of his/her annual income on water.income on water.
Hydrologic CycleHydrologic Cycle
Use of Water ResourcesUse of Water Resources
Humans use about 54% of reliable runoff Humans use about 54% of reliable runoff
Agriculture Agriculture
Power plants
Industry
Power plants
Industry
Domestic
Domestic
Fig. 15-4 p. 309Fig. 15-4 p. 309
United States
Industry 11%
Public 10%
Powercooling
38%
Agriculture38%
Water ResourcesWater Resources
• Over the last centuryOver the last century– Human population has increased 3xHuman population has increased 3x– Global water withdrawal has increased Global water withdrawal has increased
7x7x– Per capita water withdrawal has Per capita water withdrawal has
increased 4xincreased 4x– About one-sixth of the world’s people About one-sixth of the world’s people
don’t have easy access to safe waterdon’t have easy access to safe water
Human water needsHuman water needs• A person needs about 1 gallon water/day for A person needs about 1 gallon water/day for
hydrationhydration• In the U.S. each person uses about 188 In the U.S. each person uses about 188
gallons/daygallons/day• An additional 657 gallons/person/day are used An additional 657 gallons/person/day are used
for irrigation, industrial use. for irrigation, industrial use. • Total per capita use is about 2000 Total per capita use is about 2000
gal/person/daygal/person/day• If world’s water supply were 100 liters, the If world’s water supply were 100 liters, the
usable supply would be about 0.5 tspusable supply would be about 0.5 tsp• U.S. has highest per capita water withdrawal, U.S. has highest per capita water withdrawal,
followed by Canada, Australia, Russia, Japanfollowed by Canada, Australia, Russia, Japan
Too Little WaterToo Little Water Dry climate Dry climate
Drought Drought
Desiccation Desiccation
Water stress Water stress
Acute shortage
Adequate supply
Shortage
Metropolitan regions with population greater than 1 million
Fig. 15-6 p. 310Fig. 15-6 p. 310
Evaporation and transpiration
Evaporation
Stream
Infiltration
Water tableInfiltration
Unconfined aquifer
Confined aquifer
Lake
Well requiring a pump
Flowingartesian well
Runoff
Precipitation
ConfinedRecharge Area
Aquifer
Less permeable materialsuch as clay Confirming permeable rock layer
Ground WaterGround Water
Fig. 15-3 p. 308
Groundwater AquifersGroundwater Aquifers
An aquifer is an underground layer of rock An aquifer is an underground layer of rock or soil that contains water. The water is or soil that contains water. The water is held in the spaces between the rock or soil held in the spaces between the rock or soil
particles.particles.
Two Kinds of AquifersTwo Kinds of Aquifers
• A A confined aquiferconfined aquifer is a water supply which is is a water supply which is sandwiched between two layers of soil or rock that sandwiched between two layers of soil or rock that water can not pass through (impermeable layers). water can not pass through (impermeable layers).
• An An unconfined aquiferunconfined aquifer is a water supply that has an is a water supply that has an impermeable layer below it, but not above it. impermeable layer below it, but not above it.
• A confined aquifer that is under pressure is an A confined aquifer that is under pressure is an artesian aquiferartesian aquifer. The pressure can often push water . The pressure can often push water to the surface in a well drilled into an artesian to the surface in a well drilled into an artesian aquifer.aquifer.
• Usually wells need a pump to bring water to the Usually wells need a pump to bring water to the surface from the aquifer they are drilled into surface from the aquifer they are drilled into (confined and unconfined aquifers) (confined and unconfined aquifers)
Use of AquifersUse of Aquifers• We use aquifers as a source of drinking water, to We use aquifers as a source of drinking water, to
irrigate crops, and in industry.irrigate crops, and in industry.
• As with any container of water, pumping from As with any container of water, pumping from the aquifer empties it--or at least decreases the the aquifer empties it--or at least decreases the amount of water it holds. Aquifers are refilled, or amount of water it holds. Aquifers are refilled, or recharged, in areas where they are exposed on recharged, in areas where they are exposed on the surface of the earth. Water can re-enter the the surface of the earth. Water can re-enter the aquifer in these recharge areas.aquifer in these recharge areas.
How Long Does It Take The How Long Does It Take The Water To Move?Water To Move?
What Is Groundwater What Is Groundwater Depletion?Depletion?
Where Does Where Does Groundwater Depletion Groundwater Depletion
Occur In The United Occur In The United States?States?
•Drying up of wells/ water table Drying up of wells/ water table lowering lowering
•Reduction of water in streams and Reduction of water in streams and lakes lakes
•Deterioration of water quality Deterioration of water quality
•Increased pumping costs Increased pumping costs
•Land subsidence Land subsidence
•Saltwater intrusionSaltwater intrusion
What Are Some Effects What Are Some Effects of Ground Water of Ground Water
Depletion?Depletion?
Example Of Ground Water Example Of Ground Water DepletionDepletion
• In the Houston, Texas area extensive In the Houston, Texas area extensive ground-water pumping to support ground-water pumping to support economic and population growth has economic and population growth has caused water-level declines of caused water-level declines of approximately 400 feet, resulting in approximately 400 feet, resulting in extensive land-surface extensive land-surface subsidencesubsidence of of up to 10 feet. up to 10 feet.
Reduction of GroundwaterReduction of GroundwaterPumpingPumping• Improvements to irrigation technology.Improvements to irrigation technology.
• Controlling human development andControlling human development and
population growth. population growth.
• Shifting cropping patterns from water Shifting cropping patterns from water
intensive vegetation.intensive vegetation.
– – Examples include: rice, alfalfa, and Examples include: rice, alfalfa, and
Low flow rates Low flow rates Few bacteria Few bacteria Cold
temperatures Cold
temperatures
Coal strip mine runoff
Pumping well
Waste lagoon
Accidental spills
Groundwater flow
Confined aquifer
Discharge
Leakage from faulty casing
Hazardous waste injection well
Pesticides
Gasoline station
Buried gasoline and solvent tank
Sewer
Cesspool septic tank
De-icing road salt
Unconfined freshwater aquifer
Confined freshwater aquifer
Water pumping well Landfill
Low oxygen
Low oxygen
Fig. 22-9 p. 502
Groundwater Pollution Groundwater Pollution • >70,000 chemicals are used; effects of many >70,000 chemicals are used; effects of many
are not known (synergism and antagonism?)are not known (synergism and antagonism?)• Each year another 700-800 new chemicals Each year another 700-800 new chemicals
are producedare produced• 55 million tons of hazardous chemical wastes 55 million tons of hazardous chemical wastes
are produced in the US each yearare produced in the US each year• The 20 most abundant compounds in The 20 most abundant compounds in
groundwater at industrial waste disposal groundwater at industrial waste disposal sites include TCE, benzene, vinyl chloride…sites include TCE, benzene, vinyl chloride…all are carcinogens, and also affect liver, all are carcinogens, and also affect liver, brain, and nervous systembrain, and nervous system
A Few Solutions to A Few Solutions to GroundwaterGroundwaterProblems Problems • Improving irrigation efficiency.Improving irrigation efficiency.
• Household water efficiency.Household water efficiency.
• Reduction of groundwater pumping.Reduction of groundwater pumping.
• Desalination.Desalination.
• Restoration of flood plains. Restoration of flood plains.
• Increase the use of drip irrigation.Increase the use of drip irrigation.
• Use center pivot low pressure Use center pivot low pressure sprinklers.sprinklers.
• Use time controlled irrigation valves.Use time controlled irrigation valves.
• Use soil moisture detectors.Use soil moisture detectors.
• Allow farmers to sell their water Allow farmers to sell their water rightsrights
Desalinization Desalinization Fresh Water From Salt WaterFresh Water From Salt Water
DesalinationDesalination
• This can provide potable water to coastalThis can provide potable water to coastal
areas in arid climates such as Southernareas in arid climates such as Southern
California and Florida.California and Florida.
• Drawbacks include:Drawbacks include:
– – Using large amounts of electricity.Using large amounts of electricity.
– – Financially expensive.Financially expensive.
– – The process produces large amounts ofThe process produces large amounts of
wastewater that can be toxic.wastewater that can be toxic.
Household Water EfficiencyHousehold Water Efficiency• Landscaping using native or drought Landscaping using native or drought
resistant vegetation.resistant vegetation.
• Fixing leaking faucets, toilets, or Fixing leaking faucets, toilets, or irrigationirrigation
systems.systems.
• Replacing older less efficient toilets, Replacing older less efficient toilets, showerheads, and washing machines showerheads, and washing machines with water conserving models.with water conserving models.
• Collection of rain water for irrigation Collection of rain water for irrigation purposespurposes
Restoration of Historic Flood Restoration of Historic Flood PlainsPlains• Restore rivers and streams to their Restore rivers and streams to their
naturalnatural
flow patterns.flow patterns.
• Restricting urban growth in these floodRestricting urban growth in these flood
plains will accomplish the following:plains will accomplish the following:
– – Provide urban park space.Provide urban park space.
Pollution of LakesPollution of LakesEutrophication Eutrophication
Fig. 22-7 p. 499
Case Study: The Great Case Study: The Great LakesLakes
Minamata DiseaseMinamata Disease
Mercury Poisoning
Lead PoisoningLead Poisoning
Sources Sources of Water Pollutionof Water Pollution
Point Sources Point Sources Non Point Sources
Point and Nonpoint SourcesPoint and Nonpoint Sources
NONPOINT SOURCES
Urban streets
Suburban development
Wastewater treatment plant
Rural homes
Cropland
Factory
Animal feedlot
POINT SOURCES
Fig. 22-4 p. 494
Love CanalLove Canal• Landfill near Niagara Falls, NYLandfill near Niagara Falls, NY• Hooker Chemicals and Plastics Corporation Hooker Chemicals and Plastics Corporation
put wastes in abandoned canal, covered it, put wastes in abandoned canal, covered it, deeded 16 acres to Niagara Falls Board of deeded 16 acres to Niagara Falls Board of Education in 1953.Education in 1953.
• Elementary school built on site; houses built Elementary school built on site; houses built around schoolaround school
• 1976—chemicals leaking into basements1976—chemicals leaking into basements• Environmental emergency declared in 1978Environmental emergency declared in 1978• State and federal gov’ts bought >500 State and federal gov’ts bought >500
contaminated houses in 1980; 1989 people contaminated houses in 1980; 1989 people began to returnbegan to return
Solutions: Preventing and Solutions: Preventing and Reducing Surface Water PollutionReducing Surface Water Pollution
Nonpoint SourcesNonpoint Sources Point SourcesPoint Sources
Reduce runoff Reduce runoff
Buffer zone vegetation
Buffer zone vegetation
Reduce soil erosion Reduce soil erosion
Clean Water Act Clean Water Act
Water Quality Act Water Quality Act
Monitoring water qualityMonitoring water quality
• Number of colonies of fecal coliform Number of colonies of fecal coliform bacteriabacteria
Using Macroinvertebrates to Using Macroinvertebrates to determine water qualitydetermine water quality
Guess Who!Guess Who!
Solutions
Water Pollution
•Prevent groundwater contamination
•Greatly reduce nonpoint runoff
•Reuse treated wastewater for irrigation
•Find substitutes for toxic pollutants
•Work with nature to treat sewage
•Practice four R's of resource use
(refuse, reduce, recycle, reuse)
•Reduce resource waste
•Reduce air pollution
•Reduce poverty
•Reduce birth rates
Federal Water LegislationFederal Water Legislation
• Federal Water and Pollution Control Act of Federal Water and Pollution Control Act of 19561956
• Fish and Wildlife Coordination Act of 1958Fish and Wildlife Coordination Act of 1958consider wildlife in water projectsconsider wildlife in water projects
• National Environmental Policy Act of 1969National Environmental Policy Act of 1969require environmental impact require environmental impact
statementsstatements
Legislation, continuedLegislation, continued• Water Quality Improvement Act of 1970Water Quality Improvement Act of 1970
----control of oil pollution; work to eliminate control of oil pollution; work to eliminate acid mine drainage, pollution of Great Lakesacid mine drainage, pollution of Great Lakes
• CLEAN WATER ACT OF 1972CLEAN WATER ACT OF 1972----billions of $ to clean up nation’s waters; billions of $ to clean up nation’s waters; modern sewage treatment plants—huge modern sewage treatment plants—huge affectaffect
• Comprehensive Environmental Response, Comprehensive Environmental Response, Compensation, and Liability Act of 1980 Compensation, and Liability Act of 1980 (CERCLA)(CERCLA)---superfund!---superfund!
More legislationMore legislation
• Hazardous and Solid Waste Amendments Hazardous and Solid Waste Amendments to CERCLA of 1984to CERCLA of 1984--regulates underground storage tanks--regulates underground storage tanks
• Water Quality Act of 1987Water Quality Act of 1987----national policy for controlling nonpoint national policy for controlling nonpoint sources of water pollutionsources of water pollution
• Safe Drinking Water Act of 1996Safe Drinking Water Act of 1996--risk-based water quality standards, --risk-based water quality standards, consumer awarenessconsumer awareness
Ocean PollutionOcean Pollution
Fig. 22-11 p. 504
Dumping wastes in the Dumping wastes in the oceansoceans• Dumping industrial wastes off US coasts has Dumping industrial wastes off US coasts has
stopped, but dredge products are legally stopped, but dredge products are legally dumped at 110 sites in Atlantic, Pacific, and dumped at 110 sites in Atlantic, Pacific, and Gulf CoastsGulf Coasts
• US has banned dumping sewage sludge in US has banned dumping sewage sludge in ocean since 1992ocean since 1992
• 50 countries rep ~80% of world’s shipping 50 countries rep ~80% of world’s shipping fleet have agreed not to dump sewage and fleet have agreed not to dump sewage and garbagegarbage
• London Dumping Convention of 1972; 1994London Dumping Convention of 1972; 1994
Chemical cleanup methods: coagulants and dispersing agents
Chemical cleanup methods: coagulants and dispersing agents
Exxon ValdezExxon Valdez
• 1989; contaminated about 1500 km of 1989; contaminated about 1500 km of coastline; Prince William Soundcoastline; Prince William Sound
• $8 billion cost to Exxon$8 billion cost to Exxon
• 2006—17 years later, still toxic 2006—17 years later, still toxic patches of oil along some parts of patches of oil along some parts of shorelineshoreline
• Still—largest source of oil pollution is Still—largest source of oil pollution is runoff from land!runoff from land!
