Name _________Justin Powers________________________
Date ______________________
The Water Cycle
http://ga.water.usgs.gov/edu/mwater.html
Where is Earth’s Water?
1. What does it mean that the Earth is a closed system, like a terrarium? All of Earth’s water and resources stay
on Earth, they do not float off into space.
2. How does water the water amount from millions of years ago compare to today’s water amount? It is
the same amount as millions of years ago.
3. Out of all the water on Earth, what percentage is usable by humans? 31.3%
4. Of the water usable by humans, where is the largest percentage of that water found? Groundwater
5. Complete the following diagram:
Atmospheric
water-3%
Freshwater
-2.5%
Groundwa
ter-30.1%
Surface and
other
freshwater1.2%
Ice and snow- 69%
Biological Water.26%
Soil moisture- 3.8%
Rivers- .49%
Oceans96.5%
6.
7.
8.
9.
Glaciers
and ice
caps68.7%
Lakes-20.9%
Swamps and
marshes- 2.6%
Of the freshwater, where is most of the water tied up? Glaciers and ice caps
Of the remaining freshwater, where is the largest majority of that water found? Groundwater
What percentage of freshwater is found as surface water? 21%
Compare the amount of freshwater to the amount of saltwater in cubic kilometers: Salt-1487000000
Fresh-71300000
How Much Water Is There?
1. How much of the Earth’s surface is covered by water? 71%
2. Besides the ocean, where else does water exist? Water vapor, aquifers, lakes, rivers, glaciers, living
things
3. Where does most of the water people and other life on Earth come from? The surface of Earth
4. Compare the amount of groundwater to surface water: There is more surface water than groundwater
5. What term is used for the storage place of groundwater? Aquifer
6. How is groundwater recharged? Water seeps into the ground
7. How does groundwater recharge rivers? It seeps into the rivers
8. In 2005, how much surface water did the United States use? 328 billion gallons
9. In the same time period, how much groundwater did people use? 82.6 billion gallons
The Water Cycle
What is another term used for the water cycle? Hydrologic cycle
Atmosphere
1. Which two processes changes liquid water into vapor which then rises into the atmosphere?
Evaporation and evapotranspiration
2. Which process produces the majority of the vapor in the atmosphere? Evaporation
3. What percentage of vapor does transpiration add to the atmosphere? 10%
4. If all the water in the atmosphere rained down and covered the Earth, how deep would it be?
About 1 inch
Condensation
1. Define condensation: The process by which water vapor in the atmosphere is changed into liquid
water
2. Why is condensation an important part of the water cycle? It creates clouds, which are
important in the weather system
3. Besides clouds, what else can happen due to condensation? Fog can form
Evaporation
1. Define evaporation: The process by which liquid water changes from a liquid to a gas or a vapor
2. Where does most of the evaporated water come from? Oceans, seas, lakes, and rivers
3. What is necessary in order for evaporation to occur? Heat
4. What percentage of the water evaporated from the ocean is transported over land and falls as
precipitation? 10 percent
5. How long does an evaporated water molecule stay in the air? 10 days
Evapotranspiration
1. According to this website, define evapotranspiration: (beneath the diagram)
The sum of evaporation from the Earth’s surface and transpiration from living organisms
2. Define transpiration: When plants leaves release water
3. How much water in the atmosphere is due to transpiration: 10%
4. How does a plant transpire? 3000-4000 gallons a year
5. How much can an oak tree transpire during one day? 40000 gallons a year
Freshwater Storage
1. What bodies of water does surface water include: Lakes, freshwater wetlands, reservoirs and
canals, ponds, streams
2. What processes are included in “inflows” to surface water?
Precipitation, overland runoff, groundwater seepage, and tributary inflows.
3. What processes are included in “outflows” of surface water? Movement of water into groundwater,
and withdrawals by people, evaporation
Groundwater Discharge
1. Describe why groundwater is an important part of the water cycle: It contributes to flow of rivers
and streams and provides stability in wetlands habitats and environments
2. Where is the majority of groundwater found? In between rock and subsurface material
3. When are aquifers formed? When the spaces between rock and soil particles can be totally filled
with water
4. Explain how water becomes part of the groundwater: After it is precipitated, water infiltrates into
the ground and continues to travel down into the zone of saturation
5. What percentage of freshwater is groundwater? 30.1%
Groundwater Storage
1. Where does most of the water in groundwater come from? Precipitation that percolates into the
ground
2. Describe the difference between the saturated zone and the unsaturated zone: In the unsaturated
zone, water is present but doesn’t completely fill the zone, but in the saturated zone the soil is
completely full of water
3. What is the water table? The border between the zone of aeration and saturation
4. To what level would you have to dig to find water? The top of the water table
4. Label the diagram below:
Precipitation
Soil Zone
Recharge to water
table
Unsaturated zone
Water table
Saturated zone
Ice, Snow, and Glaciers
1. What is meat by storage, in relation to the water cycle? When water is going to stay in the state
that it is in for a long time
2. Where is the 90% of Earth’s ice mass found? Antarctica
3. Where is the rest of it found? The Greenland ice cap
4. What majority of freshwater is held in ice caps and glaciers? 68.7%
Infiltration
1. What is happening to water during infiltration? It is seeping into the ground and moving downward
towards the zone of saturation
2. What happens to water that infiltrates the shallow soil layer? It will move horizontally and vertically
over time
3. What happens to the water that infiltrates deeper? It will recharge groundwater aquifers
4. What is the greatest factor affecting infiltration? Precipitation
5. What happens to rain, once the soil is saturated? It moves as runoff
Oceans
1. What percentage of water is found in the ocean? 96.5
2. What percentage of evaporated water comes from the ocean? 90%
Precipitation
1. What forms of water can precipitation take? Rain, freezing rain, sleet, snow, hail
2. How does most precipitation fall? Rain
3. What has to happen before water can fall as precipitation? It has to condensate in clouds
4. How do water droplets grow? Additional condensation when particles collide
5. Draw how raindrops actually look up to 3 mm:
Snowmelt Runoff
1. In what type of climates does snowmelt runoff play a significant role in streamflow? Colder
climates
2. What percentage of freshwater in the western states comes from snowmelt runoff? 75%
Springs
1. What are springs a result of? When the surface fills with water because the soil underneath is
saturated with water
Streamflow
1. How does USGS define streamflow? The amount of water flowing in a river
2. What is a stream? Flowing water bodies
3. Why do rivers exist? Gravity moves water from higher elevation to lower elevation
4. Where does water generally seek to flow? Downhill
5. What percentage of freshwater is found in rivers? .006%
Sublimation
1. What is sublimation? Conversion between solid and gaseous states without a liquid medium
2. What is sublimation, in relation to the water cycle? Snow and ice changing into water vapor without
melting into water
3. When does sublimation occur? When there is low humidity and dry winds
4. Where on Earth does sublimation happen a lot? High altitudes
5. What is a Chinook Wind and where do they occur? Dry winds that have the moisture sucked
from them over the ocean and they occur in dry and sometimes mountainous areas
Surface Runoff
1. What is surface runoff? Runoff from the land surface
2. When does runoff occur? When rain hits saturated or impervious ground and continues to flow
Place the letter from the diagram above in the space provided next to its associated term in
the lists below:
[ I] Condensation
[ K] Evapotranspiration
[ E] Groundwater discharge
[ D] Infiltration
[ C] Snowmelt runoff to streams
[ N] Streamflow
[ Q] Surface runoff
[ A] Water storage in ice and snow
[ M] Desublimation [ R ] Plant uptake
[ H] Evaporation
[ P] Freshwater storage
[ F] Groundwater storage
[ B] Precipitation
[ O] Spring
[ L] Sublimation
[ J] Water storage in the atmosphere
[ G] Water storage in oceans