pearson elemental geosystems ch 11

The general term for clay, silt, and sand deposited by running water is ANSWER: dirt. mud. soil. alluvium.

alluvium

As a stream's carrying capacity decreases, which of the following sizes of sediments will be deposited last? ANSWER: silt gravel clay sand

clay

Watersheds are defined by ANSWER: drainage divides. fluvial units. continental divides. stream orders.

drainage divides.

Which of the following stream channel forms is likely to develop when aggradation greatly exceeds erosion? ANSWER: -meandering channels -V-shaped valleys -braided channels -straight, steep-walled channels

-braided channels

Natural levees are created during ANSWER: -low flow conditions. -normal flow conditions. -floods. -None of the above-all levees are manmade.

-floods.

Rivers east of the continental divide in the Rockies drain into the ANSWER: Pacific drainage. Gulf/Atlantic drainage. Hudson Bay/Arctic drainage. interior West drainage.

Gulf/Atlantic drainage.

The construction of a dam across a river is likely to cause ________ upstream and ________ downstream. ANSWER: aggradation; aggradation erosion; erosion erosion; aggradation aggradation; erosion

aggradation; erosion

Stream drainage patterns are determined by which of the following? ANSWER: slope differing rock resistance climatic and hydrologic variability all of these

all

A cutoff on a meandering stream results in the formation of ANSWER: a terrace. a levee. an oxbow lake. a point bar.

an oxbow lake.

An interruption in a stream's graded profile of equilibrium is called a ANSWER: base level. longitudinal interruption. nickpoint. gradation.

nickpoint.

A central peak, or a dome of a volcanic mountain, generally produces ________ drainage patterns. ANSWER: annular trellis parallel radial

radial

The effect of urbanization on a typical stream hydrograph is to ANSWER: -increase lag time between storm peak and peak stream discharge. -create a base flow. -decrease lag time between storm peak and peak stream discharge. -decrease runoff.

decrease lag time between storm peak and peak stream discharge.

As base level is approached by a stream, the ability of a stream to erode its bed ANSWER: remains constant. decreases. increases.

decreases

Of the world's largest rivers, which has the greatest discharge? -Chang Chiang (Yangtze) of Asia -Amazon River -Zaire (Congo) River -Missouri-Ohio-Mississippi river system

-Amazon River

John Wesley Powell put forward the idea of base level, which refers to ANSWER: -an imagined surface that extends inland from sea level, and is inclined gently upward. -a level below which a stream cannot erode its valley. -flat plateaus. -an evolutionary cycle of landscape development. -Both A and B are correct.

-Both A and B are correct.

Which of the following is true of the longitudinal profile of most rivers? ANSWER: -It is convex in shape. -It is concave in shape. -It always changes at a constant rate from the headwater region to the sea. -It is gentle upstream and steep downstream.

-It is concave in shape.

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

-They are characterized by rapids and low waterfalls.

Which of the following is true regarding the flooding of New Orleans in 2005? ANSWER: -The city is almost entirely below the level of the Mississippi, with parts actually below sea level. -Because the levees provide 100-year flood protection, it will not flood for another 100 years. -No one could have predicted that it would flood. -The repairs included ending the subsidence of the city.

The city is almost entirely below the level of the Mississippi, with parts actually below sea level.

Which of the following is likely to occur if the gradient of a stream increases? (Assume that the discharge and sediment load remain unchanged.) ANSWER: -The amount of aggradation in the channel will increase. -The amount of bed load transport will decrease. -The stream will begin to erode its channel and/or its banks. -The stream will begin to deposit more of its load.

The stream will begin to erode its channel and/or its banks.

As the discharge of a stream increases, which of the following also happens? ANSWER: -The rate of flow decreases. -Channel width increases but channel depth decreases. -Stream channels narrow, become shallower, and lose velocity. -Width, depth, and velocity all increase.

Width, depth, and velocity all increase.

The maximum velocity line in a stream is ANSWER: -near the bottom. -near the inside of a meander. -at the center and near the surface, corresponding with the shallowest parts of the stream channel. -at the center and near the surface, corresponding with the deepest parts of the stream channel.

at the center and near the surface, corresponding with the deepest parts of the stream channel.

The degradation of a landscape by weathering, erosion, and transportation has an ultimate "goal" of reducing the landscape down to ANSWER: -the mountain tops. -valley level. -base level, namely sea level. -continental shelf.

base level, namely sea level.

The largest material that can be carried by a stream is carried as ANSWER: truck load. bed load. dissolved load. suspended load.

bed load

The total possible load a stream can transport is its ________, whereas a stream's ability to move particles of specific size is its ________. ANSWER: bed load; sediment load discharge; competence competence; capacity capacity; competence

capacity; competence

Which of the following stream channel types is likely to develop on gently sloping surfaces composed of rocks or sediments with approximately the same resistance to erosion? (Also assume that there are no structural controls on the pattern's development.) ANSWER: deranged annular radial dendritic

dendritic

The glaciated shield regions of Canada and northern Europe have disrupted surface drainage patterns that are called ________ patterns. ANSWER: trellis annular parallel deranged

deranged

Rectangular drainage patterns form as a result of ________. ANSWER: -domal uplift -differential resistance to erosion -flow through a faulted landscape -flow through anticlinal and synclinal topography

flow through a faulted landscape

Stream-related processes are termed -hydrological. -geomorphological. -fluvial. -erosion.

fluvial

The suspended load of a stream consists of particles that are ANSWER: -in solution. -held aloft in the stream flow. -rolled and bounced along the stream bed. -dragged along the stream bed.

held aloft in the stream flow.

The ultimate base level is ANSWER: an interior basin. sea level. a dam. all of these

sea level.

Stream transport involves all of the following except ANSWER: traction. sheet flow. saltation. bed load.

sheet flow

Stream capture refers to ANSWER: -the merging of two streams flowing in the same valley. -the legal process by which a state secures rights to the waters of a river basin. -the process by which one channel erodes through a drainage divide and captures the headwater regions of another stream. -the illegal withdrawal of water from a river.

the process by which one channel erodes through a drainage divide and captures the headwater regions of another stream.

Which of the following landforms is incorrectly matched with a drainage pattern? ANSWER: -folded mountain belt trellis -topographically disrupted areas. parallel -eroded dome. annular volcano radial

topographically disrupted areas - parallel

Which drainage pattern is controlled by rock structures of variable resistance and folded strata? ANSWER: radial trellis dendritic deranged

trellis

Which of the following lists of processes are in the correct sequence as to their occurrence in nature? ANSWER: -weathering, erosion, deposition, transport -weathering, deposition, erosion, transport -weathering, erosion, transport, deposition -deposition, erosion, transport, weathering

weathering, erosion, transport, deposition

If you live in an area that was flooded by the 100-year flood last year, you can conclude that ANSWER: -you do not have to worry about another flood of that size during your lifetime. -the next 100-year flood will occur in exactly 99 years. -the next 100-year flood will occur in exactly 100 years. -you could be flooded by the 100-year flood again this year.

you could be flooded by the 100-year flood again this year.