Test Bank Docx Ch.13 Floods

Natural Disasters, 11e (Abbott)

Chapter 13 Floods

1) Between 1960 and 2009, floods in the United States resulted in an average of ________ deaths per year.

A) 1.4

B) 14

C) 135

D) 1,450

E) 145,000

2) Between 1960 and 2009, floods in the United States produced an average of ________ in damage per year. 

A) $459,000

B) $4.59 million

C) $66.76 million

D) $459 million

E) $6.76 billion

3) Base level ________.

A) is the level below which a stream cannot erode

B) for all streams is sea level

C) is the average annual flow level for a stream

D) is the minimum amount of flow possible for a stream

E) is elevation of the groundwater where the stream is flowing

4) Factor(s) that interact to make streams seek equilibrium include the ________.

A) volume of water discharged by the stream

B) amount of sediment waiting to be moved

C) slope of the stream bottom

D) sinuosity of the stream path

E) All of these choices are correct.

5) United States Geological Survey stream-gauging stations measure all but which of the following?

A) water depths

B) channel width

C) water velocity

D) oxygen isotope ratios

6) If a stream experiences more energetic water flow, the stream ________.

A) responds by increasing the sinuosity of its channel pattern through meandering

B) responds by decreasing the sinuosity of its channel pattern

C) will not change its sinuosity, but will erode sediment

D) will not change its sinuosity, but will deposit sediment

E) will not change its flow path

7) If a stream is choked with sediment and has insufficient water to carry it away ________.

A) the water will pick its way through as a braided stream

B) a peninsula is formed

C) a canyon is formed

D) a flood will occur

E) Any of these choices may happen.

8) If a stream has a meandering section, that section is most likely to be ________.

A) in its upstream section near its source or sources

B) in its downstream section, near its mouth

C) in its upstream section near its source or sources or in its downstream section, near its mouth

D) braided

9) On a given stream, small floods happen ________.

A) with the same frequency as large floods

B) more often than large floods

C) less often than large floods, which explains why we hear about large floods more often in the news

D) sometimes more often, sometimes less often than large floods, depending on long-term climate

10) Statistically, the 100-year flood has a ________ percent chance of occurring any year.

A) 1

B) 10

C) 50

D) 63

E) 2

11) What is the probability that a 100-year flood will occur at least once in 100 years?

A) 1 percent

B) 10 percent

C) 50 percent

D) 63 percent

E) 100 percent

12) Killer floods are caused by ________.

A) local thunderstorms

B) abundant rainfall lasting for days

C) the storm surges of tropical cyclones flooding the coasts

D) the breakup of winter ice on rivers

E) All of these choices are correct.

13) Most flood-related deaths in the United States are caused by ________.

A) flash floods from local thunderstorms

B) regional floods from abundant rainfall lasting for days

C) storm surges of tropical cyclones flooding the coasts

D) ice-jam floods from the breakup of winter ice on rivers

E) collapse of man-made dams

14) About 50% of flash flood deaths are ________.

A) related to people swimming across flooded rivers

B) related to people watching floods from bridges

C) related to people trying to retrieve pets from flooded homes

D) vehicle-related

E) boat-related

15) In the United States about 2.5% of the land is floodplain and home to about ________ percent of the population. 

A) 0.065

B) 0.65 

C) 6.5 

D) 65 

E) No one in the U.S. lives on floodplains because of flood-zoning legislation.

16) Why are floods so common along the Red River of the North (in North Dakota, South Dakota, and Minnesota)?

A) The Red River Valley is geologically young (about 9,000 years old) and has not carved a deep valley.

B) The gradient or slope of the riverbed is very low.

C) River flow increases as winter snow melts and meltwater runs northward into still frozen parts of the river.

D) All of these choices are correct.

17) In the late spring and summer of 1993, the Upper Mississippi River Basin experienced record high floods. However, the floodwater mass did not significantly affect the Lower Mississippi River Basin because ________.

A) the input from the Ohio River flow was low

B) there was a drought in Louisiana

C) the Southern levees were built higher during the summer before the water got there

D) All of these choices are correct.

E) None of these choices are correct.

18) The ________ is reputed to have killed more people than any other natural feature.

A) Huang (Yellow) River in China

B) Mississippi River

C) Nile River in Egypt

D) Red River of the North

E) Amazon River in Brazil

19) Efforts to control rivers include ________.

A) dams

B) levees

C) channelization

D) reducing runoff

E) All of these choices are correct.

20) A hydrograph is a plot of ________.

A) the volume of water or stream-surface height versus time

B) water quality versus time

C) sediment load versus time

D) stream elevation versus distance downstream

E) rainfall versus the drainage area

21) Hydrographs from urban settings ________ rural settings.

A) look like those from

B) show higher rates of runoff than

C) show floods are of shorter duration than in

D) show floods are of longer duration than in

E) show higher rates of runoff and show floods are of shorter duration than in

22) With respect to channelization, straightening the channel ________.

A) increases the gradient of the stream bottom, making the water flow faster

B) decreases the gradient of the stream bottom, making the water flow slower

C) increases the gradient of the stream bottom, making the water flow slower

D) decreases the gradient of the stream bottom, making the water flow faster

E) None of these choices are correct.

23) When ice dams in front of the largest glacial lakes failed, stupendous floods resulted whose passage is still recorded ________.

A) in lake sediments

B) by countryside stripped of all soil and sediment cover

C) by abandoned waterfalls

D) by a system of braided channels, now left mostly dry

E) All of these choices are correct.

24) The most famous of the ice-dam failure floods is preserved in the "channeled scablands" topography in ________.

A) Manitoba

B) Saskatchewan

C) Alberta

D) Iowa

E) Washington State

25) A braided stream has ________.

A) too much sediment to carry

B) too little sediment in suspension, causing erosion in a braided pattern

C) no relationship to the amount of sediment being transported

D) a sediment load equal to the amount of sediment it can transport

26) If a flood has a recurrence interval of ten years, it means that ________.

A) a similar-sized flood will occur once every ten years

B) a similar-sized flood has a greater probability of occurring every tenth year than during any one of the intervening years

C) in any given year a similar flood has a 1/10 chance of occurring

D) the flood must be bigger than any other flood during any given 10-year interval

E) None of these choices are correct.

27) During the great flood of July 1993 in the Upper Mississippi River Basin, the southeastern United States experienced persistent ________. 

A) low atmospheric pressure and a drought

B) high atmospheric pressure and a drought

C) low atmospheric pressure and a flood

D) high atmospheric pressure and a flood

28) The "channeled scablands" of the state of Washington were caused by ________.

A) the gentle, slow melting of glaciers

B) the failure of an ice dam during glacial melting

C) a large rainstorm

D) winds from an ancient volcanic explosion at Mt. St. Helens

E) the avulsion of a major river channel

29) Which of the following conditions led to the 1993 flood in the midcontinental United States?

A) the jet stream moving north and south more rapidly than normal

B) the jet stream locked in place over North-Central Plains for an unusually long time

C) an unusual amount of rainfall caused by the after effects of Hurricane Andrew

D) one unusually large rainstorm over Iowa, Kansas, Nebraska, and Minnesota

E) an El Niño moving over the Upper Midwest

30) The 1993 flood in the central United States was caused by ________.

A) a single large rainstorm over a large area

B) rapid melting of record winter snows during the spring 

C) several storms building up excess moisture over several months over much of the Upper Mississippi River Drainage Basin

D) a series of dam failures after an earthquake

31) Consider a typical flood plotted on a hydrograph, which of following statements is true regarding the rising and falling limb?

A) The falling limb is a mirror image of the rising limb.

B) The falling limb is steeper than the rising limb.

C) The rising limb is steeper than the falling limb.

D) The rising and falling limbs are the shape of a perfect sin wave in natural settings.

E) There is no known pattern in the relative shape of the rising and failing limbs.

32) Upstream and downstream floods differ in that upstream floods ________.

A) cover a smaller area

B) generally cause more economic damage

C) generally kill few people

D) are closer to base level

33) The recurrence interval is equal to (N + 1)/M where N is the number of years of flood records and M is ________.

A) minimum amount of discharge needed to produce a flood

B) mass of water moved in each year's maximum flood

C) the slope of the rising limb on the hydrograph of a 25-year flood

D) the absolute value of the slope of the falling limb on the hydrograph of a 50-year flood

E) the numerical rank of each year's maximum flood discharge

34) ________ are the floors of streams during a flood.

A) Flats

B) Floodplains

C) Braids

D) Meanders

E) Avulsions

35) The discharge of a stream (Q) is calculated by multiplying a stream's ________.

A) cross-sectional area (A) by its velocity (V)

B) sinuosity (S) by its cross-sectional area (A)

C) bed load (B) by its velocity (V)

D) cross-sectional area (A) by the force of gravity (g)

E) slope (S) by the force of gravity (g)

36) Streams return to equilibrium by triggering ________.

A) positive-feedback mechanisms

B) negative-feedback mechanisms

C) status quo forcing

D) hydrological forcing

E) hydrostatic forces

37) During floods a stream may leave its current channel and take a new lower-elevation course and form a new channel in a process known as ________.

A) delusion

B) braiding

C) avulsion

D) riveting

E) funneling

38) Rivers start to overflow the banks of rivers in the ________ flood stage.

A) action

B) minor

C) moderate

D) major

E) levee

39) Flood duration is not related to size of the drainage basin in which the flood is occurring.

40) The largest flood known in an area is likely to be exceeded someday by a larger one, even in an area with a long history.

41) A longitudinal cross section of a stream will show a lower gradient near the stream source and a higher gradient near the stream mouth.

42) Streams change dependent variables (e.g., channel pattern) in response to excesses in stream discharge or stream-sediment load.

43) A meandering stream lengthens its flow path, lowering the stream's gradient, and thus increasing the speed of its water flow.

44) Ignoring scale, the fact that most natural streams worldwide have the same longitudinal cross section is a testimony to the effectiveness of their negative-feedback mechanisms.

45) Statistically speaking, the larger the floods, the shorter are the recurrence times between them.

46) A specific set of criteria must be met during a flood before the President of the United States can make a Presidential Disaster Declaration under the Disaster Relief and Emergency Assistance Act.

47) It is possible to estimate the flow volume of a 100-year flood on a stream that has only 25 years of flow records.

48) When designing roads, bridges, and buildings, it is possible to save large amounts of money on initial construction costs by considering only smaller floods, but in the long run, it is commonly cheaper to build with large floods in mind.

49) Even though a "150-year flood" may occur one year, it is still possible for another of the same size to come again in the following year, or even in the same year.

50) Most flood-related deaths in the United States are caused by flash floods, and about 50 percent of these deaths are vehicle-related.

51) Large floods due to ice-dam collapses are thought to have the potential to affect global climate, due to the massive influx to the ocean of cold water, which can disrupt deep-ocean circulation.

52) The weather pattern was remarkably similar for the big floods of 1927, 1973, and 1993 in the Upper Mississippi River Basin.

53) When a flood crest passes downstream, stream level falls more rapidly than it rose.

54) The biggest floods known on Earth within the past two million years occurred during the melting of the continental ice sheets.

55) Flood frequency can be accurately predicted with only a few years of stream discharge measurements.

56) The probability that a 100-year flood will occur at least once in 100 years is 100%.

57) The probability that a 100-year flood will occur at least once in 100 years is 1%.

58) An effective mitigation strategy against flooding is to construct many sewers, gutters, and drainage channels to remove precipitation from city streets and get it to streams as quickly as possible.

59) If a dam is removed from a river, the river will respond by eroding sediment deposited in the former reservoir and transporting it downstream.

60) Between 2010-2016, flash floods and river floods combined in the United States averaged about ________ deaths per year.

A) 82

B) 95

C) 110

D) 142

61) Between 2010-2016, the United States averaged about ________ deaths per year from people driving vehicles into water associated with flooded roadways.

A) 16

B) 112

C) 37

D) 49

62) Long, narrow transient bands of warm air carrying huge volumes of water vapor are known as ________.

A) atmospheric rivers

B) pirated rivers

C) braided rivers

D) meandering rivers

63) In 1926, there were ________ if levees averaging 6 m (20 ft) along the Mississippi River.

A) 190 km

B) 290 km

C) 2900 km

D) 1500 km

64) Houses, commercial buildings, and towns are moved out of flood prone areas through a process called ________.

A) regional retreat

B) managed retreat

C) floodplain retreat

D) ordered retreat

65) ________ family members were killed by a flash flood in 2017 in Arizona due to heavy rains 8 miles upstream.

A) 4

B) 6

C) 8

D) 10