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1 | |
The change in elevation of a stream per unit length is called _________________. |
| | A) | base level |
| | B) | gradient |
| | C) | velocity |
| | D) | discharge |
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2 | |
The lowest level to which a stream may erode is called __________________. |
| | A) | base level |
| | B) | gradient |
| | C) | velocity |
| | D) | discharge |
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3 | |
As the discharge in a stream increases, load usually _________________. |
| | A) | increases |
| | B) | decreases |
| | C) | stays the same |
| | D) | none of the above |
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4 | |
A stream with too much bed load will usually have what type of channel pattern? |
| | A) | straight |
| | B) | meandering |
| | C) | braided |
| | D) | dendritic |
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5 | |
Which of the following is not a characteristic of a braided stream? |
| | A) | branching channels |
| | B) | high gradient |
| | C) | abundant bed load |
| | D) | constant discharge |
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6 | |
Usually the largest floods in a stream occur _________________. |
| | A) | very frequently, several times in one year |
| | B) | frequently, every few years |
| | C) | rarely, about every ten years |
| | D) | rarely, or once every few hundred years |
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7 | |
A 100-year flood has what percentage chance of occurring each year? |
| | A) | 1 |
| | B) | 5 |
| | C) | 10 |
| | D) | 50 |
| | E) | Cannot be determined from the information given. |
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8 | |
The cumulative probability of a 100-year flood occurring at least once in 100 years is _________________. |
| | A) | 10% |
| | B) | 33% |
| | C) | 63% |
| | D) | 100% |
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9 | |
If a dam is removed, then upstream from the former dam the river responds by _______________. |
| | A) | downcutting (lowering its bed) |
| | B) | raising its bed |
| | C) | avulsion |
| | D) | becoming a braided stream |
| | E) | decreasing its discharge |
| | F) | making no change |
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10 | |
Which of the following measurements is not needed to estimate stream discharge? |
| | A) | stream velocity |
| | B) | width of stream |
| | C) | bed load of stream |
| | D) | depth of stream |
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11 | |
Which of the following floods is not an example of a flash flood? |
| | A) | Antelope Canyon, Arizona, 1997 |
| | B) | Big Thompson Canyon, Colorado, 1976 |
| | C) | Rapid Creek, Black Hills South Dakota, 1972 |
| | D) | Red River, North Dakota, 1997 |
| | E) | none of the above (all of the above are examples of flash floods) |
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12 | |
If there was a 100-year flood on the You-Name-It River in 1960, then the next 100-year flood will occur in _________. |
| | A) | never |
| | B) | 2059 |
| | C) | 2060 |
| | D) | 2061 |
| | E) | next year |
| | F) | It’s impossible to say. |
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13 | |
Which is not a characteristic of a regional flood? |
| | A) | An extended rise of river elevation for weeks to months. |
| | B) | Large storm systems or an extended period of rainfall. |
| | C) | A small drainage basin. |
| | D) | Floodplains covered with floodwaters. |
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14 | |
Most of the damage done by floods in the U.S. occurs ______________. |
| | A) | on floodplains |
| | B) | in small tributaries |
| | C) | in delta regions |
| | D) | on uplands along major rivers |
| | E) | in deserts |
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15 | |
The process of avulsion causes ________________. |
| | A) | downcutting of the riverbed |
| | B) | wider floodplains for the river |
| | C) | slow shifting of the river's channel |
| | D) | formation of a new course for the river channel |
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16 | |
The process of avulsion is caused by _______________. |
| | A) | erosion of the river channel |
| | B) | buildup of sediment in the river channel |
| | C) | widening of the channel |
| | D) | destruction of natural levees |
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17 | |
Urbanization usually results in an increase in flood frequency because _____________. |
| | A) | less water is able to runoff in streams |
| | B) | less water is able to infiltrate into the ground, so instead is discharged rapidly into streams |
| | C) | more water is used by humans and then discharged to streams |
| | D) | rainfall is greater in urban areas than in rural areas |
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18 | |
Channelization of streams is designed to reduce flooding by _________________. |
| | A) | speeding the passage of floodwaters |
| | B) | reducing bank erosion |
| | C) | slowing down river velocity so as to reduce damage |
| | D) | increase the meandering of streams |
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19 | |
Dams are designed to reduce flooding by _______________. |
| | A) | protecting river banks from erosion |
| | B) | providing storage for flood water |
| | C) | increasing the downstream velocity of flood water |
| | D) | trapping sediment behind the dam so it can't be deposited downstream |
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20 | |
The biblical story of the great flood may have its origin in _______________. |
| | A) | floods in ancient Mesopotamia |
| | B) | initial flooding of the Black Sea region during sea level rise following the last global glaciation |
| | C) | the epic of Gilgamesh |
| | D) | all of the above |
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21 | |
The largest floods in prehistoric times were probably the result of _______________. |
| | A) | very heavy rainfall |
| | B) | hurricanes |
| | C) | ice dam failures |
| | D) | meteorite impacts |
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