qod calculate how many liters of water are wasted in 1 month by a faucet that leaks 2 drops of water...
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QODCalculate how many liters of water are wasted in 1 month by a faucet that leaks 2 drops of water per second.
(1 liter of water equals about 3500 drops)
How many gallons is this?
(1 liter equals 0.265 gallons)
QODCalculate how many liters of water are wasted in 1 month by a faucet that leaks 2 drops of water per second.
(1 liter of water equals about 3500 drops)
How many gallons is this?
(1 liter equals 0.265 gallons)
Water ResourcesWater Resources
G. Tyler Miller’sLiving in the Environment
13th Edition
Chapter 14
G. Tyler Miller’sLiving in the Environment
13th Edition
Chapter 14
Key ConceptsKey Concepts
The physical properties of water The physical properties of water
Availability of fresh water Availability of fresh water
Methods of increasing freshwater supplies Methods of increasing freshwater supplies
Using water more efficiently Using water more efficiently
Problems associated with flooding Problems associated with flooding
Water’s Unique PropertiesWater’s Unique Properties
Hydrogen bondingHydrogen bonding•Major factor in determining Major factor in determining
water’s unique propertieswater’s unique properties
O
H H+ +
--
O
H H+ +
--O
H H+ +
--
Hydrogen bondsHydrogen bonds
Covalent bondsCovalent bonds
Water’s Unique PropertiesWater’s Unique Properties
Liquid over wide temperature rangeLiquid over wide temperature range• High boiling point 100High boiling point 100°C (212°F)°C (212°F)• Low freezing point 0Low freezing point 0°C (32°F)°C (32°F)
Changes temperature slowlyChanges temperature slowly• Helps protect organismsHelps protect organisms• Moderates the earth’s climateModerates the earth’s climate• Excellent coolantExcellent coolant
High heat of evaporationHigh heat of evaporation• Absorbs heat as it changes into water Absorbs heat as it changes into water
vaporvapor• Releases heat as vapor condensesReleases heat as vapor condenses
Water’s Unique PropertiesWater’s Unique Properties Great dissolving powerGreat dissolving power
• Carries dissolved nutrients into tissueCarries dissolved nutrients into tissue• Flush waste products out of tissueFlush waste products out of tissue• All-purpose cleanserAll-purpose cleanser• Remove and dilute water-soluble Remove and dilute water-soluble
wasteswastes pHpH
• Helps maintain balance between acids Helps maintain balance between acids and basesand bases
Adhesion and cohesionAdhesion and cohesion• Surface tensionSurface tension• Wetting abilityWetting ability
Expands when it freezesExpands when it freezes• Ice floatsIce floats
Water: A Vital ResourceWater: A Vital Resource
Oceans Oceans and and
saline saline lakeslakes
97.4%97.4%
Fresh Fresh WateWater r 2.6%2.6%
Supply of Water ResourcesSupply of Water Resources
FreshwaterFreshwater Readily accessible freshwaterReadily accessible freshwater
Biota0.0001%
Biota0.0001%
Rivers0.0001%Rivers
0.0001%
Atmosphericwater vapor
0.001%
Atmosphericwater vapor
0.001%
Lakes0.007%
Soilmoisture0.005%
Groundwater0.592%
Groundwater0.592%
Ice capsand glaciers
0.1.984%
0.014%0.014%
Surface WaterSurface Water
• Surface runoffSurface runoff– Water flowing off the land into Water flowing off the land into
bodies of waterbodies of water• Reliable runoffReliable runoff
– One-third of world’s annual runoffOne-third of world’s annual runoff– Represents a stable source of Represents a stable source of
waterwater• Watershed (Drainage Basin)Watershed (Drainage Basin)
– Region from which water drainsRegion from which water drains
GroundwaterGroundwater
Evaporation and transpirationEvaporation and transpiration
EvaporationEvaporation
StreamStream
InfiltrationInfiltration
Water tableWater tableInfiltrationInfiltration
Unconfined aquiferUnconfined aquifer
Confined aquiferConfined aquifer
LakeLake
Well requiring a pumpWell requiring a pump
FlowingFlowingartesian wellartesian well
RunoffRunoff
PrecipitationPrecipitation
ConfinedConfinedRecharge AreaRecharge Area
AquiferAquifer
Less permeable materialLess permeable materialsuch as claysuch as clay
Confirming permeable rock layerConfirming permeable rock layer
Ground WaterGround Water Fig. 14-3 p. 315Fig. 14-3 p. 315
Unconfined Aquifer Recharge AreaUnconfined Aquifer Recharge Area
Use of Water ResourcesUse of Water Resources
• AgricultureAgriculture• IndustryIndustry• DomesticDomestic• Power Power
PlantsPlants
Humans use about 50% of reliable runoff Humans use about 50% of reliable runoff
United StatesUnited States
Industry 11%Industry 11%
Public 10%Public 10%
PowerPowercoolingcooling
38%38%
AgricultureAgriculture41%41%
5,500
5,000
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
500
1900 1920 1940 1960 1980 2000
Wat
er u
se (
cub
ic k
ilom
eter
s p
er y
ear) Total use
Agricultural use
Industrial use
Domestic use
Year
Water in the United States
Water in the United States• Average Average
precipitation precipitation (top)(top) in relation in relation to water-deficit to water-deficit regions andregions and
• their proximity their proximity to metropolitan to metropolitan areas areas (bottom).(bottom).
Too Little WaterToo Little Water
1)1) Dry climateDry climate• Air circulation Air circulation
patternspatterns
2)2) DroughtDrought• 21 days+21 days+• Precipitation <70%Precipitation <70%• Increased Increased
evaporationevaporation
3)3) DesiccationDesiccation• Drying of the soilDrying of the soil
4)4) Water stressWater stress• Low per capita Low per capita
availabilityavailability• Caused by Caused by
increased increased populationpopulation
• Limited runoff levelsLimited runoff levels
Acute shortage
Adequate supply
ShortageMetropolitan regions with population greater than 1 million
Water stressedWater stressed – – reliable runoff per reliable runoff per person below 1700 person below 1700 cu meters per yearcu meters per year
Water scarcityWater scarcity – per – per capita availability capita availability below 1000 cu below 1000 cu meter per yearmeter per year
500 million people live in 500 million people live in countries that are either countries that are either water stressed or water water stressed or water
scarcescarce• limited access (live far away)limited access (live far away)• arrives during short periodsarrives during short periods• hydrological povertyhydrological poverty
–Collect water from unsafe Collect water from unsafe sourcessources–Purchase from private vendorPurchase from private vendor
Increasing Fresh Water SuppliesIncreasing Fresh Water Supplies
1.1. Build dams and reservoirs to Build dams and reservoirs to store runoffstore runoff
2.2. Bring surface water from another Bring surface water from another areaarea
3.3. Withdraw groundwater.Withdraw groundwater.4.4. Convert salt water to fresh waterConvert salt water to fresh water5.5. Waste less waterWaste less water6.6. Import food to reduce water useImport food to reduce water use
Using Dams and Reservoirs to Supply More
Water
(To Dam or Not To Dam)
Using Dams and Reservoirs to Supply More
Water
(To Dam or Not To Dam)
Fig. 14-13a, p. 317
Provides water for year-round irrigation of cropland
Flooded land destroys forests or cropland and displaces people
Large losses of water through evaporation
Provides water for drinking Downstream
cropland and estuaries are deprived of nutrient-rich silt
Reservoir is useful for recreation and fishing
Risk of failure and devastating downstream flooding
Can produce cheap electricity (hydropower)
Downstream flooding is reduced
Migration and spawning of some fish are disrupted
• • Deliver nutrients to the sea which Deliver nutrients to the sea which helps to sustain coastal fisherieshelps to sustain coastal fisheries
• • Deposit silt that maintains deltasDeposit silt that maintains deltas
• • Purify waterPurify water
• • Renew and nourish wetlandsRenew and nourish wetlands
• • Provide habitats for aquatic lifeProvide habitats for aquatic life
• • Conserve species diversityConserve species diversity
Ecological Services of RiversEcological Services of Rivers
RUSSIA
MONGOLIA
CHINA
NEPAL BHUTAN
INDIABANGLADESH
BURMA LAOS
VIETNAM PACIFICOCEAN
Beijing
CHINA
JailingRiver
Chongquing
YichangWunan
YangtzeRiver
Shanghai
YELLOWSEA
EASTCHINASEA
ThreeGorges
Dam
Reservoir
China’s Three Gorges DamChina’s Three Gorges Dam
Case Study: The Colorado Basin – an Overtapped Resource
Case Study: The Colorado Basin – an Overtapped Resource
• Lake Powell, is Lake Powell, is the second the second largest reservoir largest reservoir in the U.S.in the U.S.
• It hosts one of It hosts one of the hydroelectric the hydroelectric plants located on plants located on the Colorado the Colorado River.River.
Dam
Aqueductor canal
Upper Basin
Lower Basin
IDAHO
WYOMING
UTAH
Salt Lake City
Las Vegas
CALIFORNIA
Boulder City
Los Angeles Palm
Springs
San DiegoMexicali
Yuma
Phoenix
Tucson
LOWERBASIN
ARIZONA
GrandCanyon
UPPERBASIN
Grand Junction
Denver
COLORADO
NEW MEXICO
Albuquerque
MEXICO
LakePowell
GlenCanyonDam
All-AmericanCanal Gulf of
California
0
0
100 mi.
150 km
The The ColoradColorado River o River BasinBasin
Transferring Water from One Place to AnotherTransferring Water from One Place to Another
North BayAqueductNorth BayAqueduct
South BayAqueductSouth BayAqueduct
California AqueductCalifornia Aqueduct
CALIFORNIANEVADA UTAH
MEXICO
Central ArizonaCentral ArizonaProjectProject
Colorado RiverAqueduct
Los AngelesAqueduct
Shasta Lake
Sacramento
Fresno
Phoenix
Tucson
ARIZONA
ColoradoRiver
SacramentoRiverSacramentoRiver
San FranciscoSan Francisco
Los AngelesLos Angeles
San DiegoSan Diego
Watershed transferWatershed transfer
California California Water ProjectWater Project
Central Central Arizona ProjectArizona Project
James Bay James Bay (Canada)(Canada)
Increasing Fresh Water SuppliesIncreasing Fresh Water Supplies
1.1. Build dams and reservoirs to Build dams and reservoirs to store runoffstore runoff
2.2. Bring surface water from another Bring surface water from another areaarea
3.3. Withdraw groundwater.Withdraw groundwater.
Tapping GroundwaterTapping Groundwater
•AdvantagesAdvantages– Year-round useYear-round use– No evaporation lossesNo evaporation losses– Often less expensiveOften less expensive
•Potential Problems!Potential Problems!– ManyMany
Problems with Using GroundwaterProblems with Using Groundwater
1)1)Water Table LoweringWater Table Lowering
Initial water table
Cone ofdepression
Originalwater table
Loweredwater table
Problems with Using Groundwater
Problems with Using Groundwater
2)2) Aquifer depletionAquifer depletion• Ogalala AquiferOgalala Aquifer
WYOMING SOUTH DAKOTA
NEBRASKA
COLORADO
KANSAS
OKLAHOMA
NEW MEXICO
TEXAS
0 100Miles
Kilometers
Less than 61 meters (200 ft)
61-183 meters (200-600 ft)
More than 183 meters (600 ft)(as much as 370 meters or 1,200 ft.in places)
0 160
Problems with Using GroundwaterProblems with Using Groundwater
3)3) SubsidenceSubsidence– Sinking of land when groundwater is Sinking of land when groundwater is
withdrawnwithdrawn
Other Effects of Groundwater OverpumpingOther Effects of Groundwater Overpumping
• SinkholesSinkholes form form when the roof of when the roof of an underground an underground cavern collapses cavern collapses after being after being drained of drained of groundwater.groundwater.
Problems with Using GroundwaterProblems with Using Groundwater
4)4) Saltwater Saltwater intrusionintrusion
Major irrigationwell
Well contaminatedwith saltwater
SaltwaterIntrusion
NormalInterface
Freshgroundwater
aquifer
Interface Interface
Saltwater
Sea LevelWater table
Fig. 14-11, p. 315
Major irrigation well
Well contaminated with saltwater
Water tableFresh
groundwater aquifer
Sea level
Saltwater
InterfaceSeaflo
or
Saltwater intrusion
Interface
Normal interface
Problems with Using GroundwaterProblems with Using Groundwater
5)5)Chemical contaminationChemical contamination
6)6)Reduced stream flowReduced stream flow
• Tragedy of the commonsTragedy of the commons
Converting Salt Water to Fresh WaterConverting Salt Water to Fresh Water
• DesalinationDesalination – removing dissolved – removing dissolved salts from ocean water or brackish salts from ocean water or brackish water.water.
– Distillation desalinationDistillation desalination•Heating salt water until it Heating salt water until it evaporates.evaporates.
– Reverse osmosis desalinationReverse osmosis desalination•Salt water is pumped at high Salt water is pumped at high pressure through a thin membranepressure through a thin membrane
Converting Salt Water to Fresh WaterConverting Salt Water to Fresh Water
• DesalinationDesalination – removing – removing dissolved salts from ocean dissolved salts from ocean water or brackish water.water or brackish water.
– Desalination is Desalination is very expensivevery expensive• Larger amounts of energy neededLarger amounts of energy needed
– Desalination produces Desalination produces large large quantities of wastewaterquantities of wastewater • waste disposal problemwaste disposal problem
Making it RainMaking it Rain
• Cloud SeedingCloud Seeding– Water condensation nucleiWater condensation nuclei– Silver iodide particlesSilver iodide particles
• Limited SuccessLimited Success– Not useful in dry areasNot useful in dry areas– Potential pollution from cloud Potential pollution from cloud
seeding chemicalsseeding chemicals– Legal disputes: ownership of Legal disputes: ownership of
cloudsclouds
Using Water More EfficientlyUsing Water More Efficiently
• Reduce losses due to leakageReduce losses due to leakage– 60 to75% of water people use is 60 to75% of water people use is
lost!lost!
• Causes of wasteCauses of waste– Water subsidy policyWater subsidy policy
• Artificially low cost of waterArtificially low cost of water• False sense of abundanceFalse sense of abundance
Using Water More EfficientlyUsing Water More Efficiently
• Causes of waste cont.Causes of waste cont.– Water lawsWater laws
• Doctrine of riparian rightsDoctrine of riparian rights (East) (East)– Anyone owning land adjoining stream Anyone owning land adjoining stream
has right to water has right to water
• Principle of prior appropriationPrinciple of prior appropriation (West)(West)
– First-come, first-servedFirst-come, first-served
• Common lawCommon law governs governs groundwatergroundwater– Subsurface water belongs to whoever Subsurface water belongs to whoever
owns the land above itowns the land above it
– Fragmented watershed Fragmented watershed managementmanagement
Fig. 14-18, p. 325
Center pivotCenter pivot
Drip irrigationDrip irrigation
Gravity flowGravity flow(efficiency 60% and
80% with surge valves)
Above- or below-ground pipes or tubes deliver water to individual plant roots.
Water usually comes from an aqueduct system or a nearby river.
(efficiency 90–95%)
(efficiency 80%–95%)
Water usually pumped from underground and sprayed from mobile boom with sprinklers.
Too Much Water: FloodsToo Much Water: Floods
Natural phenomena• heavy rain, melting snow
Natural phenomena• heavy rain, melting snow
Floodplain
Levee Floodwall
Dam
Reservoir
Renew and replenishRenew and replenish
Aggravated by human activities
Aggravated by human activities
Solutions: Achieving a More Sustainable Water FutureSolutions: Achieving a More Sustainable Water Future
Efficient irrigationEfficient irrigation
Water-saving technologiesWater-saving technologies
Improving water managementImproving water management
What Can You Do?Water Use and Waste
• Use water-saving toilets, showerheads, and faucet aerators.
• Shower instead of taking baths, and take short showers.
• Stop water leaks.
• Turn off sink faucets while brushing teeth, shaving, or washing.
• Flush toilets only when necessary.
• Wash only full loads of clothes or use the lowest water-level for smaller loads.
• Use recycled (gray) water for lawn, gardens, house plants, car washing.
• Wash a car from a bucket of soapy water, and use the hose for rinsing only.
• If you use a commercial car wash, try to find one that recycles its water.
• Replace your lawn with native plants that need little if any watering and decorative gravel or rocks.
• Water lawns and gardens in the early morning or evening.
• Sweep or blow off driveways instead of hosing off with water.
• Use drip irrigation and mulch for gardens and flowerbeds.
2002 Free Response Question #2