environmental science chapter 11 water 11.2 water use and management

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ENVIRONMENTAL ENVIRONMENTAL SCIENCE SCIENCE Chapter 11 Water Chapter 11 Water 11.2 Water Use and 11.2 Water Use and Management Management

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Page 1: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

ENVIRONMENTAENVIRONMENTAL SCIENCEL SCIENCE

Chapter 11 WaterChapter 11 Water

11.2 Water Use and 11.2 Water Use and ManagementManagement

Page 2: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

11.2 Water Use and 11.2 Water Use and ManagementManagement

ObjectivesObjectives Identify patterns of global water use.Identify patterns of global water use. Explain how water is treated so that it can Explain how water is treated so that it can

be used for drinking.be used for drinking. Identify how water is used in homes, in Identify how water is used in homes, in

industry, and in agriculture.industry, and in agriculture. Describe how dams and water diversion Describe how dams and water diversion

projects are used to manage freshwater projects are used to manage freshwater resources.resources.

Identify five ways that water can be Identify five ways that water can be conserved.conserved.

Page 3: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water Use and Water Use and ManagementManagement

When a water supply is polluted or When a water supply is polluted or overused, everyone living downstream overused, everyone living downstream can be affected.can be affected.

A shortage of clean, fresh water is one of A shortage of clean, fresh water is one of the world’s most pressing environmental the world’s most pressing environmental problems.problems.

According to the World Health According to the World Health Organization, more than 1 billion people Organization, more than 1 billion people lack access to a clean, reliable source of lack access to a clean, reliable source of fresh water.fresh water.

Page 4: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Global Water UseGlobal Water Use

There are three major uses for There are three major uses for water: residential use, agricultural water: residential use, agricultural use, and industrial use.use, and industrial use.

Page 5: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Global Water UseGlobal Water Use Most of the fresh water used worldwide is Most of the fresh water used worldwide is

used to irrigate crops.used to irrigate crops. However, patterns of water use are not the However, patterns of water use are not the

same everywhere. same everywhere. The availability of fresh water, population The availability of fresh water, population

sizes, and economic conditions affect how sizes, and economic conditions affect how people use water.people use water.

Industry accounts for about 19 percent of Industry accounts for about 19 percent of the water used in the world, with the the water used in the world, with the highest percent occurring in North America highest percent occurring in North America and Europe. and Europe.

About 8 percent of water is used by About 8 percent of water is used by households.households.

Page 6: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Residential Water UseResidential Water Use There are striking differences in residential There are striking differences in residential

water use throughout the world. water use throughout the world. For example, the average person in the United For example, the average person in the United

States uses about 300 L of water a day. States uses about 300 L of water a day. But in India, the average person uses only 41 L But in India, the average person uses only 41 L

of water everyday.of water everyday. In the U.S., only about half of residential water In the U.S., only about half of residential water

use is for activities inside the home, such as use is for activities inside the home, such as drinking and cooking. drinking and cooking.

The remainder of the water used residentially The remainder of the water used residentially is used for activities outside the home such as is used for activities outside the home such as watering lawns.watering lawns.

Page 7: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Residential Water UseResidential Water Use

Page 8: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water TreatmentWater Treatment

Most water must first be made Most water must first be made potable.potable.

Potable means suitable for drinking.Potable means suitable for drinking. Water treatment removes elements Water treatment removes elements

such as mercury, arsenic, and lead, such as mercury, arsenic, and lead, which are poisonous to humans even which are poisonous to humans even in low concentrations.in low concentrations.

These elements are found in polluted These elements are found in polluted water, but they can also occur water, but they can also occur naturally in groundwater.naturally in groundwater.

Page 9: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water TreatmentWater Treatment

A pathogen is a virus, microorganism, A pathogen is a virus, microorganism, or other substance that causes disease.or other substance that causes disease.

Pathogens are found in water Pathogens are found in water contaminated by sewage or animal contaminated by sewage or animal feces, but can be removed with water feces, but can be removed with water treatment.treatment.

There are several methods of treating There are several methods of treating water to make it potable. water to make it potable.

A common method includes both A common method includes both physical and chemical treatment.physical and chemical treatment.

Page 10: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Drinking-Water Drinking-Water TreatmentTreatment

Page 11: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

http://www.cas.vanderbilt.edu/bsci111a/microbiology/supplemental.htm

Page 12: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Industrial Water UseIndustrial Water Use

Industry Industry accounts for 19 accounts for 19 percent of water percent of water used in the used in the world. world.

Water is used to Water is used to manufacture manufacture goods, to goods, to dispose of dispose of wastes, and to wastes, and to generate power.generate power.

Page 13: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Industrial Water UseIndustrial Water Use Most of the water that is used in Most of the water that is used in

industry is used to cool power plants.industry is used to cool power plants. Power-plant cooling systems usually Power-plant cooling systems usually

pump water from a surface water source pump water from a surface water source such as a river or a lake, carry the water such as a river or a lake, carry the water through pipes in a cooling tower, and through pipes in a cooling tower, and then pump the water back into the then pump the water back into the source.source.

The water that is returned is usually The water that is returned is usually warmer than the source, but is generally warmer than the source, but is generally clean and can be used again.clean and can be used again.

Page 14: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Agricultural Water UseAgricultural Water Use

Agriculture accounts Agriculture accounts for 67 percent of the for 67 percent of the water used in the water used in the world. world.

Plants require a lot Plants require a lot of water to grow, of water to grow, and as much as 80 and as much as 80 percent of the water percent of the water used in agriculture used in agriculture evaporates.evaporates.

Page 15: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

IrrigationIrrigation Irrigation is a method of providing plants with Irrigation is a method of providing plants with

water from sources other than direct water from sources other than direct precipitation. precipitation.

Many different irrigation techniques are used Many different irrigation techniques are used today. today.

For example, some crops are irrigated by For example, some crops are irrigated by shallow, water filled ditches. shallow, water filled ditches.

In the U.S., high-pressured overhead sprinklers In the U.S., high-pressured overhead sprinklers are the most common form of irrigation. are the most common form of irrigation.

However, this method is inefficient because However, this method is inefficient because nearly half the water evaporates and never nearly half the water evaporates and never reaches the plant roots. reaches the plant roots.

Page 16: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

http://thidaa.wordpress.com/2010/07/13/pivot-irrigation/

http://ucmanagedrought.ucdavis.edu/corn.cfm

Page 17: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water Management Water Management ProjectsProjects

People often prefer to live in areas where People often prefer to live in areas where the natural distribution of surface water is the natural distribution of surface water is inadequate.inadequate.

Water management projects, such as Water management projects, such as dams, are designed to meet these needs.dams, are designed to meet these needs.

Water management projects can have Water management projects can have various goals, such as brining in water to various goals, such as brining in water to make a dry area habitable, creating a make a dry area habitable, creating a reservoir for drinking water, or generating reservoir for drinking water, or generating electric power, which then allows people electric power, which then allows people to live and grow crops in desert areas.to live and grow crops in desert areas.

Page 18: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water Diversion ProjectsWater Diversion Projects To supply dry regions with water, all or To supply dry regions with water, all or

part of a river can be diverted into canals part of a river can be diverted into canals that carry water across great distances.that carry water across great distances.

The Colorado River begins as a glacial The Colorado River begins as a glacial stream in the Rocky Mountains and quickly stream in the Rocky Mountains and quickly grows larger as other streams feed into it. grows larger as other streams feed into it.

As the river flows south, it is divided to As the river flows south, it is divided to meet the needs of 7 states.meet the needs of 7 states.

So much of the river’s water is diverted for So much of the river’s water is diverted for irrigation and drinking water that the river irrigation and drinking water that the river runs dry before it reaches the Gulf of runs dry before it reaches the Gulf of California.California.

Page 19: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

http://crc.nv.gov/index.asp?m=maps

http://en.wikipedia.org/wiki/The_Colorado

Page 20: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Dams and ReservoirsDams and Reservoirs A dam is a structure that is built across a A dam is a structure that is built across a

river to control a river’s flow.river to control a river’s flow. A reservoir is an artificial body of water that A reservoir is an artificial body of water that

usually forms behind a dam. usually forms behind a dam. Water from a reservoir can be used for flood Water from a reservoir can be used for flood

control, drinking water, irrigation, control, drinking water, irrigation, recreation, and industry.recreation, and industry.

Hydroelectric dams use the power of flowing Hydroelectric dams use the power of flowing water to turn a turbine that generates water to turn a turbine that generates electrical energy. electrical energy.

About 20 percent of the world electrical About 20 percent of the world electrical energy is generated using this method.energy is generated using this method.

Page 21: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

http://www.defence.pk/forums/china-far-east/90375-chinese-economy-news-updates-29.html

http://serc.carleton.edu/eslabs/drought/8b.html

Hoover Dam near Las Vegas, NV

Page 22: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

http://www.gamineral.org/point-a-dam.html

http://www.fws.gov/southeast/SHC/stories/SHCMobileRiverBasin.html

Point A Dam near Andalusia, AL

Millers Ferry Lock and Dam near Camden, AL

Page 23: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Dams and ReservoirsDams and Reservoirs But, interrupting a river’s flow can have But, interrupting a river’s flow can have

consequences. consequences. For example, when the land behind a dam For example, when the land behind a dam

is flooded, people are displaced, and is flooded, people are displaced, and entire ecosystems can be destroyed.entire ecosystems can be destroyed.

Fertile sediment also builds up behind a Fertile sediment also builds up behind a dam instead of enriching the land farther dam instead of enriching the land farther down the river, and farmland below may down the river, and farmland below may be less productive.be less productive.

Dam failure can be another problem. Dam failure can be another problem. If a dam bursts, the people living along If a dam bursts, the people living along

the river below may be killed.the river below may be killed.

Page 24: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water ConservationWater Conservation

As water sources become depleted, As water sources become depleted, water becomes more expensive.water becomes more expensive.

This is because wells must be dug This is because wells must be dug deeper, water must be piped greater deeper, water must be piped greater distances, and polluted water must distances, and polluted water must be cleaned up before it can be used.be cleaned up before it can be used.

Water Conservation is one way that Water Conservation is one way that we can help ensure that everyone we can help ensure that everyone will have enough water at a will have enough water at a reasonable price.reasonable price.

Page 25: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water Conservation in Water Conservation in AgricultureAgriculture

Most of the water loss in agriculture comes Most of the water loss in agriculture comes from evaporation, seepage, and runoff, so from evaporation, seepage, and runoff, so technologies that reduce these problems technologies that reduce these problems go a long way toward conserving water.go a long way toward conserving water.

Drip irrigation systems offer a promising Drip irrigation systems offer a promising step toward conservation. step toward conservation.

They deliver small amounts of water They deliver small amounts of water directly to plant roots by using perforated directly to plant roots by using perforated tubing. tubing.

Water is released to plants as needed and Water is released to plants as needed and at a controlled rate. at a controlled rate.

Page 26: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

http://ourfoodtech.blogspot.com/2012/06/daniel-hillel-wins-2012-world-food.html

http://environment.nationalgeographic.com/environment/photos/water-infrastructure/

Page 27: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water Conservation in Water Conservation in IndustryIndustry

In industry today, the most widely used water In industry today, the most widely used water conservation practices involve the recycling of conservation practices involve the recycling of cooling water and wastewater. cooling water and wastewater.

Instead of discharging used water into a Instead of discharging used water into a nearby river, businesses often recycle water nearby river, businesses often recycle water and use it again.and use it again.

In an innovative program, Denver, Colorado In an innovative program, Denver, Colorado pays small businesses to introduce water pays small businesses to introduce water conservation measures. conservation measures.

This not only saves money for the city and the This not only saves money for the city and the business but also makes more water available business but also makes more water available for agricultural and residential use.for agricultural and residential use.

Page 28: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water Conservation at Water Conservation at HomeHome

People can conserve water by changing a People can conserve water by changing a few everyday habits and by using only the few everyday habits and by using only the water that they need. water that they need.

Water-saving technology, such as low-flow Water-saving technology, such as low-flow toilets, can also help reduce household toilets, can also help reduce household water use.water use.

To conserve water, many people water To conserve water, many people water their lawns at night to reduce the amount their lawns at night to reduce the amount of evaporation. of evaporation.

Another way some people conserve water Another way some people conserve water outside the home is by xeriscaping, or outside the home is by xeriscaping, or designing a landscape that requires designing a landscape that requires minimal water use.minimal water use.

Page 29: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Water Conservation at Water Conservation at HomeHome

Waterless Urinalhttp://www.plumbinghelp.ca/waterless_urinal.php

Page 30: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

http://www.landscapevirginia.com/xeriscaping/

Page 31: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Solutions for the FutureSolutions for the Future

In some places, conservation alone is In some places, conservation alone is not enough to prevent water not enough to prevent water shortages, and as populations grow, shortages, and as populations grow, other sources of fresh water need to other sources of fresh water need to be developed.be developed.

Two possible solutions are:Two possible solutions are: DesalinationDesalination Transporting Fresh WaterTransporting Fresh Water

Page 32: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

DesalinationDesalination Desalination is the process of removing Desalination is the process of removing

salt from ocean water.salt from ocean water. Some countries in drier parts of the world, Some countries in drier parts of the world,

such as the Middle East, have built such as the Middle East, have built desalination plants to provide fresh water. desalination plants to provide fresh water.

Most desalination plants heat salt water Most desalination plants heat salt water and collect the fresh water that and collect the fresh water that evaporates.evaporates.

Because desalination consumes a lot of Because desalination consumes a lot of energy, the process is too expensive for energy, the process is too expensive for many nations to consider.many nations to consider.

Page 33: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

http://lmsblogs.org/blog/2012/01/31/waiter-waiter-theres-salt-in-my-water/

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Transporting WaterTransporting Water

In some areas of the world where In some areas of the world where freshwater resources are not adequate, freshwater resources are not adequate, water can be transported from other water can be transported from other regions.regions.

For example, ships regularly travel from For example, ships regularly travel from the mainland to the Greek islands towing the mainland to the Greek islands towing enormous plastic bags full of fresh enormous plastic bags full of fresh water. water.

The ships anchor in port, and fresh The ships anchor in port, and fresh water is then pumped onto the islands.water is then pumped onto the islands.

Page 35: ENVIRONMENTAL SCIENCE Chapter 11 Water 11.2 Water Use and Management

Transporting WaterTransporting Water This bag solution is also being considered This bag solution is also being considered

in the United States, where almost half of in the United States, where almost half of the available fresh water is in Alaska.the available fresh water is in Alaska.

Because 76 percent of the Earth’s fresh Because 76 percent of the Earth’s fresh water is frozen in icecaps, icebergs are water is frozen in icecaps, icebergs are another potential freshwater source.another potential freshwater source.

For years, people have considered towing For years, people have considered towing icebergs to communities that lack fresh icebergs to communities that lack fresh water. water.

But an efficient way to tow icebergs is yet But an efficient way to tow icebergs is yet to be discovered.to be discovered.

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http://www.watersafe.co.za/2010/05/06/innovations-needed-as-climate-change-sees-water-supplies-dwindle-andrew-muir/

http://frozenfly.edublogs.org/2010/11/07/icebergs-vs-glaciers/