Deck 8: The Hydrologic Cycle

Question 1

Describe the components of the hydrologic cycle. In what ways would global warming effect the cycle?

Answer 1

The hydrologic cycle, also known as the water cycle, is the continuous movement of water on, above, and below the surface of the Earth. The main components of the hydrologic cycle include evaporation, condensation, precipitation, and runoff.

Evaporation occurs when water from bodies of water, soil, and vegetation is heated by the sun and turns into water vapor. This water vapor then rises into the atmosphere. Condensation occurs when the water vapor in the atmosphere cools and forms clouds. Precipitation happens when the condensed water vapor in the clouds falls to the Earth's surface in the form of rain, snow, sleet, or hail. Runoff refers to the movement of water from the land surface into rivers, streams, and eventually into larger bodies of water such as lakes and oceans.

Global warming can have several effects on the hydrologic cycle. As temperatures rise, evaporation rates may increase, leading to more water vapor in the atmosphere. This can result in more frequent and intense precipitation events, as the atmosphere can hold more moisture. Additionally, changes in precipitation patterns can lead to altered runoff and water storage in rivers and lakes. This can result in more frequent and severe flooding in some areas, and droughts in others. Overall, global warming can disrupt the delicate balance of the hydrologic cycle, leading to changes in weather patterns and water availability.

Question 2

DDT, a toxic organochloride pesticide, was largely banned from North America in the 1970s. However, DDT is still detected in natural reservoirs today. Why is this? What can be done to expedite the removal of compounds such as DDT from the environment more quickly?

Answer 2

DDT is still detected in natural reservoirs today because it has a long half-life and can persist in the environment for decades. Additionally, DDT is still being used in some parts of the world for disease vector control, and it can be transported through air and water currents to areas where it has been banned.

To expedite the removal of compounds such as DDT from the environment more quickly, it is important to continue implementing and enforcing regulations that restrict the use of these chemicals. Additionally, investing in research and development of alternative pest control methods that are less harmful to the environment can help reduce the reliance on toxic pesticides. Furthermore, efforts to clean up contaminated sites and promote sustainable agricultural practices can also contribute to the reduction of DDT and similar compounds in the environment. It is also important to support international efforts to phase out the use of DDT and other persistent organic pollutants. By addressing the sources of contamination and implementing proactive measures, we can work towards a cleaner and healthier environment.

Question 3

The __________ cycle describes the fluxes of water between the various reservoirs of the hydrosphere.

Answer 3

hydrologic

Question 4

__________ is a key component of an array of biogeochemical cycles that control the composition of the atmosphere and influence all living creatures on Earth.

Question 5

Heat from the Sun causes of water from the ocean and land surfaces.

Question 6

With changing atmospheric conditions, some of the water vapor in the atmosphere undergoes __________ , changing from a vapor back into a liquid or solid state.

Question 7

Water's dipolar character also results in __________ in which water molecules moving through a small tube are strongly attracted to the sides of the tube.

Question 8

Streams that have no base flow dry up seasonally and are said to be __________ .

Question 9

A stream with many interlacing channels and bars is called a __________ stream.

Question 10

The bed load generally amounts to between __________ and __________percent of the total sediment load of most streams.

Question 11

The muddy character of many streams results from particles of __________ and clay carried in suspension.

Question 12

__________ are surface water bodies that are intermittently or seasonally wet.

Question 13

A __________ occurs when a stream's discharge becomes so great that it exceeds the capacity of the channel.

Question 14

During a flood, scientists record the passage of water on a __________ , a graph that indicates the stream discharge as a function of time.

Question 15

If we wish to find a reliable supply of groundwater, we search for an __________, a body of rock or regolith sufficiently porous and permeable to store and conduct significant quantities of groundwater.

Question 16

__________ is a measure of how easily a solid allows fluids to pass through it.

Question 17

A __________ is a flow of groundwater emerging naturally at the ground surface.

Question 18

A __________ will form when circulating groundwater slowly dissolves and removes carbonate rock, leaving an underground void.

Question 19

The __________ Sea, located along the border between Kazakhstan and Uzbekistan, was once the world's fourth-largest inland water body.

Question 20

Contaminated surface water bodies can often be cleaned up, or __________ , where sufficient political will and finances are available.

Question 21

The hydrologic cycle is not related to the rock cycle, rather, just to components of the atmosphere and biosphere.

Question 22

The unique properties of water allow it to play a central role in physical, chemical, and biological processes in the Earth system.

Question 23

The largest reservoir in the hydrosphere is the Antarctic ice sheet.

Question 24

The hydrologic cycle is powered by the Sun's heat, and flow within the cycle is controlled by gravity.

Question 25

A stream is water that flows down slope through a clearly defined natural channel.

Question 26

Streams and their channels are controlled by the interplay between the stream's cross-sectional area, gradient, average flow velocity, discharge, and sediment load.

Question 27

The maximum velocity of water flowing along a straight channel segment is along the banks.

Question 28

A stream's coarse bed load moves along the bottom of the stream by saltation.

Question 29

Floodplains result from the deposition of coarse sediment as a bed load overflows the banks of a stream.

Question 30

Continental divides usually coincide with the crests of great mountain ranges.

Question 31

A river is a body of inland water with an open surface, occupying a depression.

Question 32

Floods are normal and expected events; they transport and deposit sediment and replenish the mineral content of soils.

Question 33

More than 1 percent of the fresh water in the hydrosphere is groundwater.

Question 34

Immediately beneath the surface is the aerated zone, in which pore spaces contain some water and some air.

Question 35

Permeability is a measure of the interconnectedness of pore spaces and thus controls how readily a rock or sediment will transmit fluids.

Question 36

Water flows from areas where the water table is low toward areas where it's high.

Question 37

An aquifer is a body of rock or regolith sufficiently porous and permeable to store and conduct significant quantities of groundwater.

Question 38

Caves form when circulating groundwater slowly dissolves and carries away carbonate rock, leaving underground voids.

Question 39

The number of countries experiencing water stress is expected to decrease in the next few decades, partly as a result of climate change.

Question 40

Thousands of potentially harmful contaminants can enter water via the processes of the hydrologic cycle.

Question 41

Where is the largest reservoir for water in the hydrologic cycle?

A) Glacial ice.
B) Lakes and rivers.
C) Ground water.
D) The oceans.

Question 42

To prevent the long-pollution of ground water, it is in our best interest to protect which of the following areas?

A) Lakes.
B) The oceans.
C) Springs.
D) The recharge zone.

Question 43

Most of the fresh water on Earth is found in

A) Steams.
B) Ground water.
C) Rivers.
D) The ocean.

Question 44

An aquifer which flows due to the difference in pressure between the water table in the recharge area and the level of the well intake is called an

A) Acidic aquifer.
B) Alkaline aquifer.
C) Artesian aquifer.
D) Archimedes aquifer.

Question 45

Which of the following forms as a result of the dissolution of pure limestone?

A) Lakes.
B) Cave terrains.
C) Karst terrains.
D) Carbonate rivers.

Question 46

What is the primary force that dictates the downward migration of groundwater?

A) Gravity.
B) Atmospheric pressure.
C) Heavy rainfall.
D) None of these

Question 47

"Residence time" is the average time that water stays in a reservoir. There are a number of variables to residence time. Which of the following is a true statement?

A) Residence time in large-volume reservoirs are longer than in small-volume reservoirs.
B) Residence time in large-volume reservoirs are shorter than in small-volume reservoirs.
C) Residence time in large-volume reservoirs are the same as in small-volume reservoirs.
D) Large-volume versus small-volume reservoirs are not important to residence time.

Question 48

Which of the following is not a 'pathway' in the hydrologic cycle?

A) Transpiration.
B) Evaporation.
C) Condensation.
D) Precipitation.
E) None of the above. They are all pathways.

Question 49

Which of the following is not a factor that controls stream behavior?

A) The sediment load.
B) The average width and depth of the channel.
C) The channel gradient.
D) The average velocity of the water.
E) None of the above. They are all factors.

Question 50

Use the following data to calculate the discharge of a stream ("discharge" is the quantity of water passing a point on a stream bank during a given interval of time): Stream width = 10 meters. Stream average depth = 5 meters. Average flow velocity = 2 meters per second.

A) 50 square meters per second.
B) 100 square meters per second.
C) 10 square meters per second.
D) 1000 square meters per second.

Question 51

If you were traveling in an airplane and spotted a very straight segment of a stream channel, how would you interpret it?

A) The stream is flowing down a low-gradient slope.
B) The stream is flowing down a steep-gradient slope.
C) The stream is flowing down a low-gradient slope and then immediately up a steep-gradient slope.
D) Need more information.

Question 52

If a stream water is red, which of the following would best describe why the water is red?

A) The sediment load in the stream is rich in pollen.
B) The sediment load in the stream is rich in wind-blown dust from the desert.
C) The sediment load in the stream is rich in iron oxide (i.e., rust).
D) The sediment load in the stream is rich in red seaweed.

Question 53

Assume you see a meandering stream. Which of the following is a correct statement regarding the location of sediment along the bed?

A) The coarsest sediment is associated with the zone of highest velocity, which is on the outside of the bend.
B) The coarsest sediment is associated with the zone of highest velocity, which is on the inside of the bend.
C) The finest sediment is associated with the zone of highest velocity, which is on the inside of the bend.
D) The finest sediment is associated with the zone of highest velocity, which is on the outside of the bend.

Question 54

What nation contains nearly half of the world's lakes?

A) The United States.
B) Canada.
C) Brazil.
D) China.

Question 55

What is "hard water"?

A) Water rich in fine grain sediment.
B) Water with little dissolved matter and no appreciable calcium.
C) Water rich in coarse grain sediment.
D) Water rich in dissolved calcium and magnesium bicarbonates.

Question 56

Regarding the flow of groundwater, the time required along various pathways depends on what factors?

A) The distance traveled only.
B) The permeability of the rock or regolith only.
C) The permeability of the rock or regolith and the distance traveled.
D) The rate of gravity at the given location.

Question 57

What is "hydrostatic pressure"?

A) The pressure due to the weight of underlying sediment at lower levels in the zone of saturation.
B) The pressure due to the weight of underlying water at lower levels in the zone of saturation.
C) The pressure due to the weight of overlying sediment at higher levels in the zone of saturation.
D) The pressure due to the weight of overlying water at higher levels in the zone of saturation.

Question 58

If there is a layer of sediment with all of the sediment being roughly the same size, what is the approximate porosity of the layer?

A) 10%
B) 15%
C) 30%.
D) 50%

Question 59

What is an example of a material that can have high porosity but low permeability?

A) Sand.
B) Clay.
C) Cobble.
D) Pebbles.

Question 60

The United Nations estimates that by 2050 as many as 54 countries with a combined total of people could face water stress.

A) 2 million.
B) 4 million.
C) 2 billion.
D) 4 billion.

Question 61

The mighty Mississippi River flows into the Gulf of Mexico. The zone where the Mississippi River enters in the Gulf is known as the "dead zone". Here, few (if any) animals are able to live. Why is this?

A) The area has an overload of nutrients from the river, creating an algae bloom. When the algae die, their breakdown causes oxygen depletion.
B) The area has an overload of pesticides from agriculture. The pesticides kill everything in this zone.
C) The discharge of the river into the Gulf is so strong that animals are unable to leave there.
D) All of these.

Question 62

Where does the majority of precipitation go after it falls?

A) Base flow
B) Overland flow and storm flow.
C) Evaporation and transpiration.
D) Infiltration into groundwater.

Question 63

Why is water considered a "dipolar" molecule?

A) Because it has a positive and negative end.
B) Because the hydrogen molecules are positive and the oxygen molecule is neutral.
C) Because its molecular structure looks like the shape of a magnet.
D) None of these.

Question 64

If there is excessive pumping of well water, what is most likely to happen?

A) The excessive pumping will lower the water table.
B) Salt water will be sucked into coastal wells.
C) The excessive pumping will cause subsidence.
D) All of these

Question 65

Where is the water table in a swamp?

A) Well above the surface.
B) Well below the surface.
C) At the surface.
D) Generally, 2 miles below the surface.

Question 66

Which of the following rivers do not drain into the Mississippi River?

A) Ohio River.
B) Missouri River.
C) Arkansas River.
D) Red River.
E) Colorado River.

Question 67

What is the release of water vapor to the atmosphere by plants called?

A) Condensation.
B) Evaporation.
C) Infiltration.
D) Transpiration.

Question 68

What will happen to sea levels when large amounts of water is stored in ice sheets and continental glaciers?

A) Sea level will rise.
B) Sea level will drop.
C) Sea level will stay the same.

Question 69

With regards to a meandering stream or river, where will the majority of erosion occur?

A) On the inside of the bend.
B) On the outside of the bend
C) Equally on the outside and the inside of the bend.

Question 70

If a stream begins at an elevation of 600 meters and flows a distance of 200 kilometers to the ocean, what is the average gradient?

A) 3 meters per kilometer.
B) 12 meters per kilometer.
C) 0.33 meters per kilometer.
D) 6 meters per kilometer.

Question 71

Which of the following would have the largest capacity to naturally remove sewage pollutants from groundwater?

A) Granite.
B) Limestone.
C) A mixture of clay and sand.
D) Coarse gravel.

Question 72

The most important variable to erosion is

A) Ice.
B) Wind.
C) Running water.
D) Wave motion.

Question 73

Which of the following is a cutoff, meander loop?

A) An ellipse.
B) An oxbow.
C) A dogbow.
D) A rainbow.

Question 74

How does deforestation effect the hydrologic cycle?

A) The lack of vegetation alters the porosity of the soil thereby effecting infiltration.
B) The removal of plants lessens transpiration thereby effecting water source.
C) The lack of vegetation alters the permeability of the soil thereby effecting infiltration.
D) All of these.