Chapter 10: Water: Hydrolic Cucle and Human Use Flashcards
1
Q
How much volume did the Aral Sea lose?
A
90%
2
Q
How many feet did the Aral Sea water level drop by?
A
53 feet
3
Q
What percent of all water is salt water?
A
97.5%
4
Q
Fresh water
A
contains < 0.1% salt
5
Q
What percent of fresh water is bound up in ice caps and glaciers?
A
67%
6
Q
What contains water?
A
- streams
- rivers
- ponds
- lakes
- swamps
- estuaries
- groundwater
- bays
- oceans
- atmosphere
7
Q
What have humans constructed to control water?
A
huge infastructures
8
Q
What will challenge water management infastructure?
A
Increasing population
9
Q
What will affect the hydrologic cycle?
A
Climate change
10
Q
Hydrologic (water) cycle
A
the cycling of water through the Earth
11
Q
Evaporation
A
water molecules leave liquid state and enter gaseous state
12
Q
Transpiration
A
loss of water vapor from plants through leaf pores
13
Q
Condensation
A
the collecting of water molecules in the gaseous state to form the liquid state
14
Q
Precipitation
A
water returns to the land and oceans
15
Q
Green water
A
water in vapor form
16
Q
Blue water
A
water in liquid form
17
Q
Humidity
A
amount of water vapor in air
18
Q
Relative humidity
A
the amount of water vapor as a percent of what the air can hold at a particular temperature
19
Q
What is the opposite of evaporation
A
Condensation
20
Q
Aerosols
A
microscopic liquid or solid particles
21
Q
What happens when condensing intensifies?
A
Droplets become larger, gravity pulls them to Earth as precipitation
22
Q
Trade winds
A
Earth’s rotation deflects winds east and west
23
Q
Rain shadow
A
the dry region downwind of a mountain range
24
Q
Where do deserts occur on mountains?
A
The leeward side
25
Infiltration-runoff ratio
the amount of water that soaks into the ground compared with the amount that runs off
26
Watershed
all the land area contributing to a stream or river
27
Surface waters
ponts, lakes, streams, rivers, etc. on the Earth's surface
28
Capillary water
held in the soil, according to the soil's capacity
29
Evapotranspiration
the combination of evaporation and transpiration
30
Gravitational water
is not held in the soil
31
Percolation
trickling of water through pores or cracks in the soil under the pull of gravity
32
Groundwater
water accumulated in the earth
33
Water table
the upper surface of groundwater
34
What does groundwater lie on top of?
an impervious layer of rock or clay
35
Aquifers
layers of porous material through which groundwater moves
36
Recharge area
the area where water enters an aquifer
37
Seep
water flows out in a wide area
38
Spring
water flows from a small opening
39
Four categories of human impacts on the hydrologic cycle
1. changes to Earth's surface
2. changes to Earth's climate
3. Atmospheric pollution
4. Withdrawls for human use
40
What is water's largest use for?
Irrigation, then industry and direct human use
41
What are most increases in withdrawl of water due to?
Increases in agriculture
42
How much does irrigation account for of freshwater consumption in the U.S.?
65%
43
What percent of domestic water comes from groundwater sources?
37%
44
What percent of demestic water comes from surface water?
63%
45
Where do rural people in developing nations get water?
Wells, rivers, lakes, rainwater
| - women often have to walk long distances
46
Whater in developing nations is often...
polluted with waste
47
How many people use polluted water?
1.1 billion
48
How many people die each year due to polluted water?
1.6 million (mostly children
49
Millennium Development Goal 7
increase access to safe drinking water
50
The Ogallala aquifer
supplies water to seven U.S. states (20% of the irrigated land in the U.S.)
51
How much have the water tables in the Ogallala aquifer dropped and how much does it continue to drop a year?
30-60 m (100-200ft)
| 6ft/year
52
What does sustainability depend on?
balancing withdrawal rates with recharge rates
53
Land subsidence
gradual setting of the land
54
Sinkhole
another kind of land subsidence
55
What five possibilities exist to meet the future water needs?
1. Capture more runoff water
2. Tapping more groundwater
3. Desalting seawater
4. Using less water
5. Making food production more efficient
56
How can more runoff water be captured?
New dams
57
How many new dams become operational each year?
260
58
What river was China's Three Gorges Dam constructed across?
Yangtze River
59
The centerpiece of the Chinese government's efforts to industrialize
Three Gorges Dam
60
The largest hydroelectric project in the world
Three Gorges Dam
61
Groundwater depletion
the greatest threat to irrigated agriculture
62
What else is polluting groundwater?
fertilizers, pesticides, animal waste, and industrial chemicals
63
Desalination
desalting of seawater for domestic use
64
Most people in the U.S. can afford...
desalinized water
65
How many gallons/person/day do people in developing nations use?
1
66
How much water do people in the U.S. use per day?
100 gallons per day (380 liters)
67
Instead of thinking about how much water is available and where we get it, what should we be thinking?
How much water is available and how we can best use it
68
Why has the rate of water use dropped?
Conservation
69
Current flood or center-pivot irrigation...
wastes huge amounts of water
70
What does the drip irrigation method use?
pipes with holes to drip water at the base of each plant
71
What does the drip irrigation method do?
wastes less water, retards salination, increases yields
72
Why don't farmers switch to drip irrigation?
It's cheaper to use traditional method than switch
73
How does the government try to get people to switch to drip irrigation?
it pays $400 per acre in subsidies
74
What would reducing subsidies do?
encourage water conservation through using more efficient irrigation technologies
75
Who cannot afford irrigation?
Rural poor in developing countries
76
What do low-cost treadle pumps allow farmers to do?
irrigate fields
77
How does the dreadle work?
like a step exercise machine
78
Xerscaping
planting plants that don't require watering
79
50 million U.S. low-flow toilets save...
600 million gallons/day
80
Gray water
slightly dirtied water from sinks, showers, tubs, and laundry
81
What does conservation tillage enhance?
rainfall retention and soil fertility
82
What does conservation tillage decrease?
erosion
83
Water wars
conflicts between using water for drinking and using it for agricutlure
84
What does the U.S. need?
A water policy to collect data on water resources and problems and issue recommendations
85
What must be the primary strategy for meeting future needs
Water efficiency
86
Water subsidies
must be reduced or eliminated
87
Polluters
must be charged according to their effluents
88
Dams
must be operated to maintain river flow that simulates natural flow regimes
89
The U.S. must provide...
international development aid
