"our Global Environment" Chapter 14

Front 1

Describe how water moves through the planet?

Back 1

-It's called the hydrologic cycle.
-It's a closed system, circulating from one part of the earth to another, changing in form from liquid to solid or gas and back to liquid.
-It remains in constant amount.
-Only a very small % is readily available for human use.

Hint 1

pgs 458-459

Front 2

Discuss the hydrologic cycle?
What are the principal processes involved in it?

Back 2

-It's powered by energy from the sun that causes water to evaporate from the surface of the oceans, rivers, lakes, and soil.
-It's an important factor in the redistribution of heat around the earth, which is involved in weather and climate.

Hint 2

1. Evaporation of water from surface waters and the soil.
2. Transportation of water by plants. (sometimes #1 & 2 are together, called evapotranspiration)
3. Transport of atmospheric water from one place to another as water vapor or as liquid water droplets and ice crystals in clouds.
4. Precipitation when atmospheric water vapor condenses and falls as rain, hail, sleet, or snow.
5. Runoff, whereby water that has fallen finds its way back to the oceans, flowing either on or under the surface of the continents.
pg 458

Front 3

How much water is needed per day?

Back 3

-The human body needs 1-3 liters for digestion of food, transport of nutrients and hormones, and removal of wastes.
-The bare minimum needed is considered 50 liters for drinking, food preparation, cooking, washing, and bathing.
-In most urban areas, sewers will not transport wastes efficiently if per capita water use is less than 100 liters a day.

Hint 3

pg 461

Front 4

Discuss the water problem in rural Third World areas?

Back 4

-The problem may not be lack of water, but rather that the source of water is far from the point of use.
-Women may spend several hours hauling water, leaving little time for more economically productive tasks.
-The physical effort involved in carrying water long distances exerts a toll on rural women.
-When safe water is in short supply, personal hygiene and basic sanitation is neglected.

Hint 4

pgs 461-462

Front 5

Discuss the water problem in urban Third World areas?

Back 5

-Water supply systems are in poor condition or are unreliable.
-The necessity of buying water means less $ for other things.
-When safe water is in short supply, personal hygiene and basic sanitation is neglected.

Hint 5

pgs 461-462

Front 6

Discuss the prospects of desalination and how it's done.

Back 6

-Pressures on the world's freshwater resources are spurring developments that make desalination projects technologically feasible and increasingly common in water-short areas.
-An enormous amount of energy is needed to power the process, making the cost high. It's currently too expensive for irrigation or industrial purposes.
-Traditional fuel-intensive methods involve heating water under pressure then injecting it into a low pressure chamber where it "flashes" into steam which is captured and condensed into pure water.
-Modern (more energy-efficient) methods use reverse osmosis, where seawater is forced under high pressure through semi-permeable membranes that permit passage of water molecules but screen out sodium & chlorine.

Hint 6

pgs 460-461

Front 7

Describe water stress versus water scarce areas?
What problems do these situations cause?

Back 7

-Water stress areas are areas where the amount of renewable freshwater per person is under 1,700 cubic meters annually.
-Water scarce areas have water availability under 1,000 cubic meters per capita annually.

Hint 7

Inadequate water supplies can adversely impact food production, economic development, human health, the provision of sanitary services, and the viability of natural ecosystems.
pg 463

Front 8

What impact does population have on water?

Back 8

-In both water-rich and water-poor areas, pollution is rendering much of the available supply usable without extensive, expensive treatment.
-Water demand is determined by a society's level of affluence and technological development (the largest consumption are in the rich industrial nations).
-The amount of available water in a region is determined by precipitation and is finite, so amount available per capita is determined by population size.

Hint 8

pgs 463-464

Front 9

Discuss one political issue of water?

Back 9

261 large rivers flow between two or more countries, and 80% of available freshwater is in shared river basins, which creates fights over use and pollution.

Hint 9

pg 464

Front 10

Discuss using groundwater as a source of water?

Back 10

-Over half of Americans and many people worldwide rely on groundwater for their drinking water.
-Most rivers receive much of their flow from groundwater seepage, and may dry up or be reduced if too much water is pumped from groundwater supplies.
-Groundwater is usually cleaner and purer than most surface water sources because it is filtered through soil (removes bacteria, materials, and other contaminants).
-Evaporation is usually nil and seasonal fluctuations in supply are small so they are dependable year-round.
-The expense of digging a well is less than piping water to a source.

Hint 10

pg 466

Front 11

What is the zone of saturation?

Back 11

-The water table from which we get groundwater is the upper limit of it.
-It is an area where the spaces between rock particles are completely filled with water (these moisture-laden strata are called aquifers).
-It extends downward until it is limited by an impermeable layer of rock.

Hint 11

pg 467

Front 12

What is the zone of aeration?

Back 12

-It is above the zone of saturation.
-It's an area where some soil moisture may be found useful for plants but incapable of being pumped out by humans.

Hint 12

pg 467

Front 13

What determines the amount of water that any given aquifer can hold?

Back 13

-Its porosity (the ratio of the spaces between the rock particles to the total volume of rock).
-Sand and gravel aquifers are examples of rocks with high porosity.
-The rate of water movement through an aquifer varies with the type of rock it contains.
-Good aquifers have many pores and cracks.

Hint 13

pg 468

Front 14

What is challenging about groundwater pollution?
What kinds of users are particularly vulnerable to them?

Back 14

-Groundwater pollution is out of sight and difficult to detect without sophisticated chemical analyses.
-Many pollutants in groundwater are colorless, odorless, and tasteless.
-Chemical pollutants will not be flushed out of an aquifer for many years after the source of contamination is cut off due to the very slow rate of groundwater flow.
-Cleanup of a polluted aquifer is expensive and time-consuming, so protection strategies focus on preventing pollution in the first place instead of cleaning up after damage is done.

Hint 14

Private wells
pgs 468, 470

Front 15

What are the most significant sources of contamination?

Back 15

-Waste storage, treatment, or disposal facilities.
-Septic systems
-Pipes, materials transport, transfer operations.
-Nonpoint sources of pollution

Hint 15

pgs 468, 470

Front 16

Discuss the groundwater polluter of waste storage, treatment, or disposal facilities.

Back 16

-Unplanned seepage from open dumps, landfills, waste ponds, underground storage tanks, tailing piles.
-This is a severe threat if these facilities are improperly sited.
-In the US, petroleum products that leak from underground storage tanks constitute the leading source of groundwater pollution, with landfill seepage close behind.

Hint 16

pgs 468-470

Front 17

Discuss the groundwater polluter of septic systems.

Back 17

On-site disposal facilities constitute the third most commonly reported source of groundwater contamination in the US.

Hint 17

pg 470

Front 18

Discuss the groundwater polluter of pipes, materials transport, and transfer operations.

Back 18

Unintentional leakage from sewers or oil pipelines or accidental spills during transport or transfer of hazardous substances can be another significant source.

Hint 18

pg 470

Front 19

Discuss the groundwater polluter of nonpoint sources of pollution.

Back 19

Are substances discharged as a result of other activities, such as irrigation practices, mine drainage, field application of farm chemicals or manures.

Hint 19

pg 470

Front 20

What are some causes and consequences of groundwater depletion?

Back 20

Over-pumping is causing a rapid decline in the water table in regions where people are dependent on groundwater.

Hint 20

-It can permanently deplete the groundwater supply, or render it uneconomical to exploit.
-Aquifer depletion can precipitate the drying up of many surface lakes and streams, especially in dry climates.
-In coastal areas, it has resulted in migration of seawater into depleted aquifers, contaminating existing freshwater supplies.
-Land subsidence is occurring, along with formation of fissures, faults, and huge sinkholes.
-Thousands of acres of irrigated lands are being abandoned.
pgs 471-472

Front 21

What is "fossil" water and where is an example of it?

Back 21

It is a non-renewable resource, deposited millions of years ago but due to changes in geology and/or climate, replenishment is not possible.

Hint 21

The Ogallala Aquifer
pg 471

Front 22

How is groundwater replenished?
What can affect this process?

Back 22

They are recharged by moisture filtering downward from the surface or by seepage from a lake or stream.

Hint 22

Urban sprawl strips land of vegetation and covers land with buildings and asphalt, reducing the amount of precipitation that can penetrate the soil.
pg 472

Front 23

What is the recharge area?
What are some of its features.

Back 23

The area of land that is the main source of the groundwater inflow.

Hint 23

-It has permeable soils.
-May be many miles from the point at which the water is pumped from the ground.
-A major threat to quality and quantity of groundwater is the growth of industrial, commercial, and residential development within the recharge area.
pg 472

Front 24

What is water conservation and why is it used?

Back 24

Refers to "demand management" of water resources, and can include reducing overall use, reducing waste, and recycling used water so it can be used for other purposes.

Hint 24

Managing demand shows more promise for ensuring adequate water resources than does increasing supply.
pg 476

Front 25

Discuss agriculture's role in water consumption.

Back 25

-Worldwide, it accounts for the most water use.
-Irrigation water is almost always priced far below its true value, so farmers have little incentive to invest in more efficient irrigation technologies, wasting about 60% of the water applied.
-Use of water-saving irrigation is used on less than 1% of crops.

Hint 25

pgs 476-477

Front 26

Discuss industry's role in water consumption.

Back 26

-Worldwide, it is the second-largest user of water.
-Huge amounts of water are needed by factories and power plants.
-Industrial water use can be reduced by recycling the water into other uses, since it's not "consumed."
-Increasingly stringent federal mandates requiring treatment of industrial wastewater prior to discharge, along with the escalating costs of waste treatment and disposal, have given incentive to industry to start reducing use.

Hint 26

pgs 476-477

Front 27

Discuss households' role in water consumption.

Back 27

-Account for a very small percentage of water usage.
-Municipal efforts to restrict residential water use has started recently.

Hint 27

pg 478

Front 28

Discuss using rational water pricing as an effective conservation program.

Back 28

-Imposing higher unit costs on water use above a specified level encourages conservation.
-The failure of cities to meter homes discourages water conservation because consumers are unable to see a connection between the amount of water they use and the price they pay.

Hint 28

pg 478

Front 29

Discuss using leak detection/correction as an effective conservation program.

Back 29

It's a substantial way to reduce water use.

Hint 29

pg 478

Front 30

Discuss using installation of water-saving plumbing devices as an effective conservation program.

Back 30

The Energy Pollution Act of 1992 established mandatory nationwide water efficiency standards for all toilets, urinals, faucets, and shower heads installed in the US after 1997.

Hint 30

pg 482

Front 31

Discuss using altered landscape practices an effective conservation program.

Back 31

Some communities have enacted legislation restricting the amount of yard space property owners can devote to grass.

Hint 31

pg 483

Front 32

Discuss the use of dams, like the Yangtze Megadam.

Back 32

-Dam-building is done to ensure adequate supply of water for irrigating crops to control flooding.
-Third World leaders view large dams as symbols of modernity and a highly visible source of national pride.
-There are serious environmental and social impacts, including adverse effects of fish, periodic flooding that washes away small islands and critical habitat, high rates of erosion, extensive tree removal, loss of high-quality agricultural land and small villages, and diminished ability to flush human and industrial wastewater downstream so pollution will be worsened in the river.
-An added challenge is relocation of people who are currently living in areas that will be flooded.

Hint 32

pgs 474-475

Front 33

Discuss the international sale of water.

Back 33

-Involves the idea that water should be regarded as a product, to be bought & sold.
-Large-scale trans-border commerce in bulk water is unlikely, due mostly to the expense.

Hint 33

pgs 480-481