Chapter 14 Water-Overview of SurfaceWater (dams, water cycle, etc) NOT aquifer, pollutants, conservation

Chapter 14Chapter 14

Water-Overview of Water-Overview of SurfaceWater (dams, SurfaceWater (dams,

water cycle, etc)water cycle, etc)NOT aquifer, pollutants, NOT aquifer, pollutants,

conservationconservation

Chapter Overview QuestionsChapter Overview Questions

Why is water so important, how much freshwater Why is water so important, how much freshwater is available to us, and how much of it are we is available to us, and how much of it are we using?using?

What causes freshwater shortages, and what can What causes freshwater shortages, and what can be done about this problem?be done about this problem?

What are the advantages and disadvantages of What are the advantages and disadvantages of withdrawing groundwater?withdrawing groundwater?

What are the advantages and disadvantages of What are the advantages and disadvantages of using dams and reservoirs to supply more water?using dams and reservoirs to supply more water?

Chapter Overview Questions Chapter Overview Questions (cont(cont’’d)d)

What are the advantages and disadvantages of What are the advantages and disadvantages of transferring large amounts of water from one transferring large amounts of water from one place to another?place to another?

Can removing salt from seawater solve our Can removing salt from seawater solve our water supply problems?water supply problems?

How can we waste less water?How can we waste less water? How can we use the earthHow can we use the earth’’s water more s water more

sustainably?sustainably? What causes flooding, and what can we do What causes flooding, and what can we do

about it?about it?

Core Case Study: Water Conflicts Core Case Study: Water Conflicts in the Middle East - A Preview in the Middle East - A Preview

of the Futureof the Future

Many countries in Many countries in the Middle East, the Middle East, which has one of which has one of the worldthe world’’s highest s highest population growth population growth rates, face water rates, face water shortages.shortages.

Figure 14-1Figure 14-1

Water Conflicts in the Middle East: Water Conflicts in the Middle East: A Preview of the FutureA Preview of the Future

Most water in this dry region comes from the Most water in this dry region comes from the Nile, Jordan or Tigris rivers.Nile, Jordan or Tigris rivers.

Countries are in disagreement as to who has Countries are in disagreement as to who has water rights.water rights.

Currently, there are no cooperative Currently, there are no cooperative agreements for use of 158 of the worldagreements for use of 158 of the world’’s 263 s 263 water basins that are shared by two or more water basins that are shared by two or more countries.countries.

WATERWATER’’S IMPORTANCE, S IMPORTANCE, AVAILABILITY, AND RENEWALAVAILABILITY, AND RENEWAL

Water keeps us alive, moderates climate, Water keeps us alive, moderates climate, sculpts the land, removes and dilutes sculpts the land, removes and dilutes wastes and pollutants, and moves wastes and pollutants, and moves continually through the hydrologic cycle.continually through the hydrologic cycle.

Only about 0.02% of the earthOnly about 0.02% of the earth’’s water s water supply is available to us as liquid freshwater.supply is available to us as liquid freshwater.

Types of Surface WaterTypes of Surface Water1.1. Lentic- non-flowingLentic- non-flowing

a.a. Lake-larger, more diverse, often more Lake-larger, more diverse, often more oxygenoxygen

b.b. Pond-smaller, less diverse, less oxygen. Pond-smaller, less diverse, less oxygen. Light penetrates entire body of waterLight penetrates entire body of water

2.2. Lotic- flowingLotic- flowing

a.a. River- larger, more volumeRiver- larger, more volume

b.b. Stream- smaller, less volumeStream- smaller, less volume

COLD vs WARM Water and OxygenCOLD vs WARM Water and Oxygen

Cont.Cont.

3.3. Wetlands- terrestrial areas saturated part of Wetlands- terrestrial areas saturated part of the time with water. Can be fresh or saltwater.the time with water. Can be fresh or saltwater.

Wetland ServicesWetland Services

a.a. BiodiversityBiodiversity

b.b. Water Trap (flood control)Water Trap (flood control)

c.c. Carbon Dioxide TrapCarbon Dioxide Trap

d.d. Pollutant TrapPollutant Trap


Some precipitation infiltrates the ground and Some precipitation infiltrates the ground and is stored in soil and rock (groundwater).is stored in soil and rock (groundwater).

Water that does not sink into the ground or Water that does not sink into the ground or evaporate into the air runs off (surface evaporate into the air runs off (surface runoff) into bodies of water.runoff) into bodies of water.– The land from which the surface water drains The land from which the surface water drains

into a body of water is called its into a body of water is called its watershedwatershed or or drainage basindrainage basin..

Fig. 14-3, p. 308

Unconfined Aquifer Recharge Area

Precipitation Evaporation and transpiration Evaporation

Confined Recharge Area

Runoff

Flowing artesian well

Recharge Recharge Unconfined Unconfined AquiferAquifer

Stream Well requiring a pumpInfiltration Water

table LakeInfiltration

Unconfined aquifer

Confined aquiferConfining impermeable rock layer Confining impermeable rock layer

Less permeable Less permeable material such as claymaterial such as clay


We currently use more than half of the worldWe currently use more than half of the world’’s s reliable runoff of surface water and could be reliable runoff of surface water and could be using 70-90% by 2025.using 70-90% by 2025.

About 70% of the water we withdraw from rivers, About 70% of the water we withdraw from rivers, lakes, and aquifers is not returned to these lakes, and aquifers is not returned to these sources.sources.

Irrigation is the biggest user of water (70%), Irrigation is the biggest user of water (70%), followed by industries (20%) and cities and followed by industries (20%) and cities and residences (10%).residences (10%).

Water in the Water in the United StatesUnited States

Average Average precipitation (top) precipitation (top) in relation to in relation to water-deficit water-deficit regions and their regions and their proximity to proximity to metropolitan areas metropolitan areas (bottom).(bottom).


Case Study: Freshwater Case Study: Freshwater Resources in the United StatesResources in the United States

17 western states 17 western states by 2025 could face by 2025 could face intense conflict over intense conflict over scarce water scarce water needed for urban needed for urban growth, irrigation, growth, irrigation, recreation and recreation and wildlife.wildlife.


TOO LITTLE FRESHWATERTOO LITTLE FRESHWATER

About 41% of the worldAbout 41% of the world’’s population lives in s population lives in river basins that do not have enough river basins that do not have enough freshwater.freshwater.

Many parts of the world are experiencing:Many parts of the world are experiencing:– Rivers running dry.Rivers running dry.– Lakes and seas shrinking.Lakes and seas shrinking.– Falling water tables from overpumped aquifers.Falling water tables from overpumped aquifers.

Left off here 10-8-2014Left off here 10-8-2014

Stress on the WorldStress on the World’’s River s River BasinsBasins

Comparison of the amount of water available Comparison of the amount of water available with the amount used by humans.with the amount used by humans.


Case Study: Who Should Own Case Study: Who Should Own and Manage Freshwater and Manage Freshwater

ResourcesResources

There is controversy over whether water There is controversy over whether water supplies should be owned and managed by supplies should be owned and managed by governments or by private corporations.governments or by private corporations.

European-based water companies aim to European-based water companies aim to control 70% of the U.S. water supply by buying control 70% of the U.S. water supply by buying up water companies and entering into up water companies and entering into agreements with cities to manage water agreements with cities to manage water supplies.supplies.

How Would You Vote?How Would You Vote?

Should private companies own or manage most of Should private companies own or manage most of the world's water resources?the world's water resources?

How Would You Vote?How Would You Vote?

Should private companies own or manage most of Should private companies own or manage most of the world's water resources?the world's water resources?– a. No. Democratically elected governments, which are a. No. Democratically elected governments, which are

accountable to the voters, should own and manage accountable to the voters, should own and manage water resources.water resources.

– b. Qualified yes. Governments should own the water, b. Qualified yes. Governments should own the water, but expert private companies should manage it.but expert private companies should manage it.

– c. Depends. Each case must be decided independently. c. Depends. Each case must be decided independently. The record on private versus public ownership is mixed.The record on private versus public ownership is mixed.

– d. Yes. Private companies have more expertise and d. Yes. Private companies have more expertise and experience in managing water resources than most experience in managing water resources than most government bureaucrats. government bureaucrats.

TOO LITTLE FRESHWATERTOO LITTLE FRESHWATER

Cities are outbidding farmers for water Cities are outbidding farmers for water supplies from rivers and aquifers.supplies from rivers and aquifers.

Countries are importing grain as a way to Countries are importing grain as a way to reduce their water use.reduce their water use.

More crops are being used to produce More crops are being used to produce biofuels.biofuels.

Our water options are:Our water options are:– Get more water from aquifers and rivers, Get more water from aquifers and rivers,

desalinate ocean water, waste less water.desalinate ocean water, waste less water.

USING DAMS AND USING DAMS AND RESERVOIRS TO SUPPLY RESERVOIRS TO SUPPLY

MORE WATERMORE WATER

Large dams and reservoirs can produce cheap Large dams and reservoirs can produce cheap electricity, reduce downstream flooding, and electricity, reduce downstream flooding, and provide year-round water for irrigating cropland.provide year-round water for irrigating cropland.

But they also displace people and disrupt aquatic But they also displace people and disrupt aquatic systems. (silt build-up, nutrient removal, systems. (silt build-up, nutrient removal, temperature change, migration, habitat temperature change, migration, habitat degradation and fragmentation)degradation and fragmentation)


Case Study: The Colorado Basin Case Study: The Colorado Basin – an Overtapped Resource– an Overtapped Resource

The Colorado River has so many dams The Colorado River has so many dams and withdrawals that it often does not and withdrawals that it often does not reach the ocean.reach the ocean.– 14 major dams and reservoirs, and canals.14 major dams and reservoirs, and canals.– Water is mostly used in desert area of the U.S.Water is mostly used in desert area of the U.S.– Provides electricity from hydroelectric plants Provides electricity from hydroelectric plants

for 30 million people (1/10for 30 million people (1/10 thth of the U.S. of the U.S. population).population).

Case Study: The Colorado Basin Case Study: The Colorado Basin – an Overtapped Resource– an Overtapped Resource

Lake Powell, is the Lake Powell, is the second largest second largest reservoir in the reservoir in the U.S.U.S.

It hosts one of the It hosts one of the hydroelectric hydroelectric plants located on plants located on the Colorado the Colorado River.River.


The Colorado River BasinThe Colorado River Basin

The area The area drained by this drained by this basin is equal basin is equal to more than to more than one-twelfth of one-twelfth of the land area of the land area of the lower 48 the lower 48 states.states.


How Would You Vote? How Would You Vote? Do the advantages of large dams Do the advantages of large dams

outweigh the disadvantages?outweigh the disadvantages?

– a. No. Large dams inflict extensive a. No. Large dams inflict extensive environmental damage and humans must learn environmental damage and humans must learn to meet their needs without them.to meet their needs without them.

– b. Yes. Dams are critical in providing water and b. Yes. Dams are critical in providing water and electricity for people, especially in developing electricity for people, especially in developing countries. countries.

Case Study: Case Study: ChinaChina’’s Three Gorges Dams Three Gorges Dam

There is a debate over whether the advantages There is a debate over whether the advantages of the worldof the world’’s largest dam and reservoir will s largest dam and reservoir will outweigh its disadvantages.outweigh its disadvantages.– The dam is 1.4 miles long- 400 mile lake.The dam is 1.4 miles long- 400 mile lake.– The electric output will be that of 18 large coal-The electric output will be that of 18 large coal-

burning or nuclear power plants.burning or nuclear power plants.– It facilitates ship travel reducing transportation costs.It facilitates ship travel reducing transportation costs.– Dam displaced 1.3 million people.Dam displaced 1.3 million people.– Dam is built over seismic fault and already has small Dam is built over seismic fault and already has small

cracks. cracks.

Will have cost 30 over billion dollars at completionWill have cost 30 over billion dollars at completion Lack of waste disposalLack of waste disposal Cultural lossCultural loss Biodiversity lossBiodiversity loss Ecosystem issuesEcosystem issues

http://www.nytimes.com/2011/05/20/world/asia/20gorges.html?scp=3&sq=three+gorges+dam&st=nyt




Dam RemovalDam Removal

Some dams are being removed for ecological Some dams are being removed for ecological reasons and because they have outlived their reasons and because they have outlived their usefulness.usefulness.– In 1998 the U.S. Army Corps of Engineers In 1998 the U.S. Army Corps of Engineers

announced that it would no longer build large dams announced that it would no longer build large dams and diversion projects in the U.S.and diversion projects in the U.S.

– The Federal Energy Regulatory Commission has The Federal Energy Regulatory Commission has approved the removal of nearly 500 dams.approved the removal of nearly 500 dams.

– Removing dams can reestablish ecosystems, but Removing dams can reestablish ecosystems, but can also re-release toxicants into the environment.can also re-release toxicants into the environment.

TRANSFERRING WATER FROM TRANSFERRING WATER FROM ONE PLACE TO ANOTHERONE PLACE TO ANOTHER

Transferring water can make unproductive Transferring water can make unproductive areas more productive but can cause areas more productive but can cause environmental harm.environmental harm.– Promotes investment, jobs and strong economy.Promotes investment, jobs and strong economy.– It encourages unsustainable use of water in It encourages unsustainable use of water in

areas water is not naturally supplied.areas water is not naturally supplied.

Case Study: The California Case Study: The California ExperienceExperience

A massive A massive transfer of water transfer of water from water-rich from water-rich northern northern California to California to water-poor water-poor southern southern California is California is controversial.controversial.


Case Study: The Aral Sea DisasterCase Study: The Aral Sea Disaster

The Aral Sea was once the worldThe Aral Sea was once the world’’s fourth s fourth largest freshwater lake.largest freshwater lake.


http://www.orexca.com/aral_sea.shtmlhttp://www.orexca.com/aral_sea.shtml

p://www.mapsofworld.com/tajikistan/shrinking-p://www.mapsofworld.com/tajikistan/shrinking-aral-sea-map.htmlaral-sea-map.html

Case Study: The Aral Sea DisasterCase Study: The Aral Sea Disaster Diverting water from the Aral Sea and its two Diverting water from the Aral Sea and its two

feeder rivers mostly for irrigation has created feeder rivers mostly for irrigation has created a major ecological, economic, and health a major ecological, economic, and health disaster.disaster.– About 85% of the wetlands have been About 85% of the wetlands have been

eliminated and roughly 50% of the local bird and eliminated and roughly 50% of the local bird and mammal species have disappeared.mammal species have disappeared.

– Since 1961, the seaSince 1961, the sea’’s salinity has tripled and the s salinity has tripled and the water has dropped by 22 meters most likely water has dropped by 22 meters most likely causing 20 of the 24 native fish species to go causing 20 of the 24 native fish species to go extinct.extinct.

FloodingFlooding

TOO MUCH WATERTOO MUCH WATER Heavy rainfall, rapid snowmelt, removal of Heavy rainfall, rapid snowmelt, removal of

vegetation, and destruction of wetlands vegetation, and destruction of wetlands cause flooding.cause flooding.

Floodplains, which usually include highly Floodplains, which usually include highly productive wetlands, help provide natural productive wetlands, help provide natural flood and erosion control, maintain high water flood and erosion control, maintain high water quality, and recharge groundwater.quality, and recharge groundwater.

To minimize floods, rivers have been To minimize floods, rivers have been narrowed with levees and walls, and narrowed with levees and walls, and dammed to store water.dammed to store water.

TOO MUCH WATERTOO MUCH WATER

Comparison of St. Louis, Missouri under Comparison of St. Louis, Missouri under normal conditions (1988) and after severe normal conditions (1988) and after severe flooding (1993).flooding (1993).


Documents

Chapter 14 Water-Overview of SurfaceWater (dams, water cycle, etc) NOT aquifer, pollutants, conservation