XIII - Water

Question 1

Freshwater makes up about what percentage of all water?

Answer 1

2.6%

Question 2

Freshwater composition

Answer 2

1. 984% Ice caps & glaciers
2. 592% Groundwater
3. 014% Readily accessible freshwater

Question 3

Readily accessible freshwater breakdown

Answer 3

0. 007% lakes
1. 005% soil moisture
2. 001% atmospheric water vapor
3. 0001% rivers
4. 0001% biota

Question 4

What percentage of Earth’s water is readily accessible freshwater?

Answer 4

0.003%

Question 5

What percent of freshwater is used for agriculture?

Answer 5

69%
(60%–80% wasted)
800 gallons = 1 lb
grain–beef

Question 6

What percent of freshwater is used for industry?

Answer 6

23%
100,000 gallons = 1 car
1,000 gallons = 1 lb of
aluminum

Question 7

What percent of freshwater is used for domestic purposes?

Answer 7

8%

Question 8

surface hydrology

Answer 8

Local precipitation leads to surface runoff, ground infiltration, & evapotranspiration (evaporation + transpiration).

Question 9

Surface water

Answer 9

precipitation that does not infiltrate

the ground or evaporate

Question 10

Watershed

Answer 10

region from which water drains into a

water body

Question 11

Groundwater

Answer 11

water that infiltrates the ground & is

stored in voids between soil particles

Question 12

aquifers

Answer 12

porous, water–saturated layers of soil or

rock through which groundwater flows

Question 13

recharge area

Answer 13

any area of land through which water

passes into an aquifer

Question 14

Unconfined aquifers

Answer 14

have a zone of infiltration
above (unsaturated) & a water table below which
is saturated.

Question 15

Confined aquifers

Answer 15

bounded above & below by
less permeable rock; groundwater in this type of
aquifer is confined under pressure

Question 16

Groundwater moves from

Answer 16

the recharge area
through an aquifer & out to a discharge area (well,
spring, lake, geyser, stream, or ocean)

Question 17

Causes of water shortages

Answer 17

Dry climate
Drought
Desiccation
Water stress

Question 18

Drought

Answer 18

a period in which precipitation is lower &

evaporation is higher than normal

Question 19

Desiccation

Answer 19

drying of the soil as a result of deforestation

& overgrazing

Question 20

Processes involved in groundwater hydrology

Answer 20

Evaporation
Runoff
Precipitation
Transpiration
Infiltration

Question 21

Components involved in groundwater hydrology

Answer 21

Confined aquifer recharge area
Unconfined aquifer recharge area
Confined aquifer
Unconfined aquifer
Flowing artesian well
Stream
Lake

Question 22

Pros of dams & reservoirs

Answer 22

Useful for recreation & fishing
Produce cheap hydro power
Provide year-round irrigation of cropland
Downstream flooding is reduced

Question 23

Cons of dams & reservoirs

Answer 23

Enormous losses of water through evaporation
Expensive to construct
Disrupted fish migration
Downstream cropland deprived of nutrient rich soil
Danger of collapse
Mass of water can cause earthquakes
flooded land destroys forests/ croplands & displace people

Question 24

Ways to supply more water

Answer 24

Dams & reservoirs
Water transfer
Groundwater supplies
Desalination
Reverse Osmosis

Question 25

Dams & reservoirs example

Answer 25

Colorado River

Question 26

Colorado River

Answer 26

system of dams & canals provides electricity & cheap | water for agriculture, industry, & cities

Question 27

Why doesn't the Colorado River make it to the Gulf of California?

Answer 27

• limited water supply must be divided between farmers, | ranchers, cities, Native Americans, Mexico, & wildlife

Question 28

Colorado River conflict

Answer 28

population growth in the lower basin is increasing | demand beyond the allocated supply

Question 29

California Water Project Problem

Answer 29

• most of the rainfall is in northern California • most of the population growth & agriculture is in southern California

Question 30

California Water Project solution

Answer 30

• water transferred to the south via dams, pumps, & | aqueducts

Question 31

California Water Project controversy

Answer 31

• southern California wants more water for growing cities • much of the water transferred is wasted by inefficient irrigation • the north needs the water for fisheries & flushing pollutants out of San Francisco Bay ©

Question 32

Groundwater supplies problems

Answer 32

Groundwater in the U.S. is being withdrawn at about | four times its replacement rate

Question 33

Consequences of this problem

Answer 33

``` • aquifer depletion • aquifer subsidence land sinks when water is withdrawn • saltwater intrusion ```

Question 34

Using water efficiently

Answer 34

``` Increase efficiency of irrigation Use recycled water Fix leaky pipes Water-saving toilets, faucets, & shower heads Xeriscaping ```

Question 35

How to increase efficiency of irrigation

Answer 35

drip irrigation, central–pivot, computer monitoring

Question 36

How to use recycled water

Answer 36

treat gray water from showers, washing machines for | reuse

Question 37

Xeriscaping

Answer 37

plant drought–tolerant vegetation in residential | communities located in arid & semi–arid areas

Question 38

Desalinization

Answer 38

Making fresh water | from salt water

Question 39

How does desalinization work

Answer 39

Boiling salt water-> steam -> collect steam

Question 40

Reverse osmosis

Answer 40

Making freshwater from salt water using hydrostatic and osmotic pressure

Question 41

Flooding

Answer 41

result of heavy, prolonged rain or rapid snowmelt causing water in a river to overflow its channel

Question 42

How can human activities exacerbate flooding?

Answer 42

either increasing the probability of a flood or | increasing the severity of a flood

Question 43

Human activities that | exacerbate flooding

Answer 43

• Removing vegetation, logging, overgrazing, forest fires, mining, urbanization • Destruction of wetlands • Building in floodplains & replacing vegetation with concrete

Question 44

How can destroying wetlands contribute to excess flooding?

Answer 44

wetlands absorb surface runoff & release it | slowly to the river

Question 45

How can replacing vegetation with concrete contribute to excess flooding?

Answer 45

loss of vegetation causes rapid runoff of | rainwater