Question 1

Which of the following is obvious when standing on a stream bank?

Accepted Answer

A)  channel depth 
B)  channel slope 
C)  flow velocity 
D)  channel outline

Question 2

Drainage basins are separated from one another by

Accepted Answer

A)  divides. 
B)  tributaries. 
C)  headwaters. 
D)  playa.

Question 3

________ would not increase the intensity of a flash flood.

Accepted Answer

A)  Steep slopes 
B)  Paved ground 
C)  A narrow bedrock canyon 
D)  A broad alluvial fan

Question 4

Why would we want to know the 100-year flood recurrence interval?

Accepted Answer

The answer of Why would we want to know the...

Question 5

________ has the most rivers with high sediment loads.

Accepted Answer

A)  North America 
B)  South America 
C)  Southeast Asia/China 
D)  Europe/Russia

Question 6

What would happen if you used data from a very dry set of years to compute the recurrence interval calculations?

Accepted Answer

The answer of What would happen if you used data...

Question 7

Name some purposes of dams.

Accepted Answer

The answer of Name some purposes of dams....

Question 8

Why is a stream able to pick up a grain of sand, but not a smaller grain of silt?

Accepted Answer

A)  Gravity forces the silt to remain on the ground. 
B)  Certain patterns of water flow work better for larger particles. 
C)  Adhesion keeps the silt particles attached to the rock below. 
D)  Cohesion keeps the silt particles attached to each other.

Question 9

A ________ of sea-level causes a lowering of base-level and ________ in the lower part of a stream valley that terminates in the ocean.

Accepted Answer

A)  rising, incision 
B)  rising, sedimentation 
C)  lowering, sedimentation 
D)  lowering, incision

Question 10

Based on observations, geologists have determined that this factor does not help to determine whether a stream will have a meandering or braided pattern.

Accepted Answer

A)  bank stability 
B)  stream power per stream bed area 
C)  discharge variability 
D)  channel slope

Question 11

How is stream power calculated?

Accepted Answer

A)  multiply average flow velocity and volume of flow 
B)  multiply shear stress and average flow velocity 
C)  divide shear stress by average flow velocity 
D)  divide average flow velocity by volume of flow

Question 12

Sediment is deposited in a stream when

Accepted Answer

A)  stream power is less than required to move the sediment carried in from upstream. 
B)  stream power is equal to bedload. 
C)  bedload is greater than stream power. 
D)  stream power is greater than required to move the sediment carried in from upstream.

Question 13

Why does water released from a dam erode the streambed so much more than it would have before the dam existed?

Accepted Answer

A)  It has a greatly increased velocity. 
B)  It has more stream power than it would have had before the dam. 
C)  The dry stream bed below the dam weakens while it is left dry. 
D)  The stream power now exceeds the sediment load by a great amount.

Question 14

Which of the following is not a reason that grain size of sediment tends to decrease downstream?

Accepted Answer

A)  gravity 
B)  abrasion 
C)  decreasing shear force 
D)  rounding

Question 15

Figure 16.28 
-Using Figure 16.28 in your textbook, a flood level that occurred five times in 50 years is known as

Accepted Answer

A)  a 5-year flood. 
B)  a 10-year flood. 
C)  a 25-year flood. 
D)  a 50-year flood.

Question 16

Judge the following sentence according to the criteria given below. Sediment loads are largest in areas of steep relief because river slopes are steeper and steep valley walls are more prone to mass movement.

Accepted Answer

A)  The assertion and the reason are both correct, and the reason is valid. 
B)  The assertion and the reason are both correct, but the reason is invalid. 
C)  The assertion is correct but the reason is incorrect. 
D)  The assertion is incorrect but the reason is correct. 
E)  Both the assertion and the reason are incorrect.

Question 17

A stream increases its channel slope as it moves downstream. If the water depth remains the same or decreases slightly, this stream will

Accepted Answer

A)  deposit some of its sediment load due to a decrease in shear stress. 
B)  erode additional sediment load due to an increase in shear stress. 
C)  continue to carry the same sediment load as there is no change in shear stress. 
D)  deposit some of its sediment load due to a increase in shear stress. 
E)  erode additional sediment load due to an decrease in shear stress.

Question 18

If two streams undergo the same downstream drop in elevation of 300 meters, which stream would have the lowest channel slope?

Accepted Answer

A)  highly sinuous stream 
B)  moderately sinuous stream 
C)  straight channel 
D)  not enough information provided

Question 19

The area where the flow is faster and deeper around the outside of a channel bend is called

Accepted Answer

A)  a cutbank. 
B)  a meander. 
C)  a point bar. 
D)  a braid.

Question 20

Streams preferentially erode ________ and ________ valleys where rock is most easily eroded.

Accepted Answer

A)  deep, wide 
B)  deep, narrow 
C)  shallow, wide 
D)  shallow, narrow

Exam 16: Streams: Flowing Water Shapes the Landscape