Landforms Quiz 5

19. Which of the following is incorrect regarding floodplains? a. They are formed by recurrent flooding in the area adjacent to the stream. b. Natural levees on either side of a stream are formed during times when the stream is at flood stage and overflows the bank. c. They are generally low-lying areas. d. They are characterized by rapids and low waterfalls.

d. They are characterized by rapids and low waterfalls.

7. A squeeze-and-release action works to loosen and lift rocks in a stream channel. This is an example of a. deposition. b. hydraulic action. c. abrasion. d. suspension.

b. hydraulic action.

6. Which of the following channel characteristics adjusts in response to changes in energy of flow and sediment load in the channel? a. channel slope b. channel width and depth c. both channel slope and channel width and depth d. None of these-river channel form is controlled exclusively by the type of rock or sediment through which the river flows

c. both channel slope and channel width and depth

8. Stream transport involves all of the following except a. saltation. b. bed load. c. traction. d. sheet flow.

d. sheet flow.

30. The Colorado River, which carved the Grand Canyon, no longer reaches the sea because of water extraction. a. True b. False

a. True

16. A cutoff on a meandering stream results in the formation of a. an oxbow lake. b. a levee. c. a point bar. d. a terrace. e. a braided stream.

a. an oxbow lake.

. The largest material that can be carried by a stream is carried as a. bed load. b. suspended load. c. dissolved load. d. truck load.

a. bed load.

26. Erosion of the walls of a channel normally occurs on the outside curve of a meander. a. True b. False

a. True

28. Deforestation in the headwater regions of a river can cause the river to flood more frequently in downstream areas. a. True b. False

a. True

20. Natural levees are created during a. floods. b. normal flow conditions. c. low flow conditions. d. None of these-all levees are manmade

a. floods.

27. The Amazon River, the world's largest in stream discharge, has built an enormous arcuate delta into the Atlantic. a. True b. False

b. False

29. Rivers make excellent political boundaries given that they are obvious, clearly defined landform features. a. True b. False

b. False

15. If you wanted to build a structure on a river bank-especially one that flows through unconsolidated sediments-you should build the structure __________ to maximize its lifetime. a. along the cutbank b. above the point bar c. in a delta d. Any of these is equally safe.

b. above the point bar

3. Watersheds are defined by a. continental divides. b. drainage divides. c. stream orders. d. fluvial units.

b. drainage divides.

12. The downstream portion of a river a. generally becomes more sluggish. b. generally is of higher velocity, although it is masked by reduced turbulence. c. features greater hydraulic action than do upstream portions. d. has lower discharges than do upstream portions.

b. generally is of higher velocity, although it is masked by reduced turbulence.

4. Which of the following is incorrectly matched? a. rills - small-scale grooves in the land surface b. drainage divides - ridges that control the direction of drainage c. Allegheny and Missouri rivers - form the Monongahela at Pittsburgh d. Delaware River basin - comprised of parts of five states

c. Allegheny and Missouri rivers - form the Monongahela at Pittsburgh

23. The effect of urbanization on a typical stream hydrograph is to a. create a base flow. b. increase lag time between storm peak and peak stream discharge. c. decrease runoff. d. decrease lag time between storm peak and peak stream discharge.

d. decrease lag time between storm peak and peak stream discharge

24. Which of the following is true of New Orleans and the passage of Hurricane Katrina? a. Only one levee was breached. b. The flood protection features failed only after their design-failure limits were reached. c. Sections of New Orleans are below sea level. d. Six investigations found that the protection system was flawless.

c. Sections of New Orleans are below sea level.

21. When a river reaches a base level, its forward velocity rapidly decelerates as it enters a larger body of standing water and __________ is formed. a. an estuary b. an alluvial terrace c. a delta d. a stream terrace

c. a delta

13. If the capacity of a stream is exceeded, __________ will occur. a. downcutting b. erosion of valley walls c. aggradation d. both downcutting and erosion of valley walls

c. aggradation

14. The construction of a dam across a river is likely to cause __________ upstream and __________ downstream. a. erosion; aggradation b. erosion; erosion c. aggradation; erosion d. aggradation; aggradation

c. aggradation; erosion

2. The ultimate base level is a. a drainage divide. b. a dam. c. sea level. d. All of these.

c. sea level.

22. Over the past 5000 years, the Mississippi River has produced how many distinct deltaic formations? a. only the present formation has existed b. two c. seven d. fifteen

c. seven

17. Which is typical of a rejuvenated system? a. entrenched meanders b. oxbow lakes c. increased downcutting d. terraces e. entrenched meanders, increased downcutting, and terraces only

e. entrenched meanders, increased downcutting, and terraces only

25. Rivers have played a relatively minor role in the geography of human history. a. True b. False

b. False

11. The suspended load of a stream consists of particles that are a. rolled and bounced along the stream bed. b. held aloft in the stream flow. c. dragged along the stream bed. d. dissolved in solution.

b. held aloft in the stream flow.

5. Steep slopes and some relief generally produce which drainage pattern? a. dendritic b. deranged c. parallel d. annular

c. parallel

18. An interruption in a stream's graded profile of equilibrium is called a a. gradation. b. longitudinal interruption. c. base level. d. nickpoint.

d. nickpoint.

1. Which of the following lists of processes are in the correct sequence as to their occurrence in nature? a. deposition, erosion, transport, weathering b. weathering, erosion, deposition, transport c. weathering, deposition, erosion, transport d. weathering, erosion, transport, deposition

d. weathering, erosion, transport, deposition

10. Bed load is moved by a. saltation. b. traction. c. suspension. d. All of these. e. saltation and traction only.

e. saltation and traction only.