Deck 5: Running Water and Groundwater

Question 1

Sediment deposition occurs primarily in what part of a river system?

A)the head waters
B)the drainage divide
C)the trunk stream
D)near the outlet
E)the flood plain

Answer 1

D

Question 2

A stream's turbulence is strongly influenced by its ________.

A)temperature
B)sediment load
C)velocity
D)viscosity
E)sinuosity

Answer 2

C

Question 3

Sediment is neither stored nor produced ________.It is primarily a zone of transport in a river system.

A)in the head waters
B)in the drainage divide
C)in the trunk stream
D)near the outlet
E)in the flood plain

Answer 3

C

Question 4

Water plays an important role in sculpting the landscape of continents because ________.

A)water is a major cause of erosion on land
B)water contributes to plant and animal life that strongly affects the landscape
C)water deposits sediments in areas like the Grand Canyon and Yellowstone National Park where they landscape is changing rapidly
D)water moves through streams that are a major cause of mass wasting
E)ground water causes sinkholes and domes that change the landscape rapidly

Question 5

A ________ stream pattern is developed only on growing mountains like volcanoes or where the land surface is tectonically doming upward.

A)radial
B)dendritic
C)boreal
D)trellis

Question 6

Which of the following is not a significant factor in determining whether precipitation will soak into the ground or run off on the surfaces?

A)steepness of the slope
B)vegetation
C)saturation level
D)lithology
E)amount and duration of precipitation

Question 7

Which of the following is not a factor influencing a stream's flow velocity?

A)channel slope
B)channel sinuosity
C)channel roughness
D)channel width and cross sectional shape
E)the amount of water in the channel

Question 8

The release of water vapor to the atmosphere by plants is called ________.

A)evaporation
B)degassing
C)transpiration
D)infiltration

Question 9

The Trellis drainage pattern shown below develops ________.

A)in areas of relatively uniform surface materials
B)on isolated volcanic cones or domes
C)on highly jointed bedrock
D)in areas of alternating weak and resistant bedrock
E)in areas of folded and fractured domes

Question 10

Laminar flow,where water moves in approximately straight-line paths,characterizes ________.

A)fast-moving streams
B)slow-moving streams
C)the edges of channels
D)the bottoms of channels
E)all of the above

Question 11

The main process that links water in the atmosphere with water on the Earth's surface is ________.

A)transpiration
B)infiltration
C)evaporation
D)condensation
E)wind

Question 12

Which of the following is the correct definition of stream gradient?

A)the distance traveled by water in a channel times a drop in elevation
B)the drop in elevation of a stream divided by the distance the water travels
C)the water pressure at the bottom of the stream divided by the stream's width
D)the increase in discharge of a stream per unit drop in elevation

Question 13

A dendritic (tree-like)drainage pattern develops in regions where the underlying material is relatively uniform so the major control on the water movement is ________.

A)vegetation
B)slope
C)saturation
D)climate
E)sediment load

Question 14

As a stream changes from its headwaters to its mouth,which of the following is not likely to occur?

A)Flow velocity decreases.
B)The channel gets wider downstream.
C)Sediment size gets smaller downstream.
D)The channel gets smoother.
E)The volume of water increases.

Question 15

A stream begins at an elevation of 200 meters and flows a distance of 400 kilometers to the ocean.What is the average gradient?

A)2 m/km
B)2 km/m
C)0)5 m/km
D)0)5 km/in

Question 16

The Mississippi River has an average discharge of 17,300 cubic meters per second but the ________ River discharges 12 times more water than the Mississippi River.

A)Colorado
B)Nile
C)Yangtze
D)Amazon
E)Yukon

Question 17

Sediment production occurs primarily in ________ part of a river system.

A)the head waters
B)the drainage divide
C)the trunk stream
D)the outlet
E)the flood plain

Question 18

Approximately how much of the Earth's water supply is saline?

A)20%
B)43%
C)67%
D)98%
E)100%

Question 19

Which one of the following statements is correct?

A)Sea level drops when water is stored in expanding ice sheets and continental glaciers.
B)Sea level rises when water is added to the oceans through increased rainfall and increased inflow from rivers.
C)Sea level drops when evaporation rates increase over the oceans and when this extra atmospheric moisture falls on land as rain.
D)Sea level rises when water is stored in expanding ice sheets and continental glaciers.

Question 20

Which of the following is not part of the water cycle?

A)water evaporating from a lake
B)water infiltrating into the soil and bedrock
C)calcium carbonate dissolving in soil water and groundwater
D)water moving into creeks and streams following a rainstorm

Question 21

________ are characteristics of downcutting streams and a youthful stage of valley evolution.

A)Rapids and lots of whitewater
B)Wide floodplains
C)U-shaped,cross-valley profiles
D)Meandering channels and natural levees

Question 22

People learned by trial and error years ago how to paddle a canoe upstream in meandering rivers,knowing where the strongest currents were located.Assuming you don't want to go backwards,what is the best paddling route to maximize your speed upstream?

A)Keep on the outside bends,near the cut banks,as much as possible.
B)Stay in midchannel.
C)Stay on the inside bend of meanders,crossing over whenever the meander turns so you can stay on the inside bend.
D)Always stay close to one bank or the other,regardless of how the river bends.

Question 23

The suspended load of a stream ________.

A)is deposited before the bed load
B)is highly soluble substances
C)moves along the bottom
D)usually consists of fine particles

Question 24

A natural,meandering,river channel is modified into a more or less straight and smooth,canal-like channel.Which of the following statements is correct?

A)The natural channel had a lower gradient and less friction than the modified channel.
B)The straight channel has a higher gradient and more friction than the natural channel.
C)The natural channel had a lower gradient and higher friction than the straight channel.
D)All of the above statements are true.

Question 25

If you just want to go for a swim in a meandering river and want to find a sandy beach,where is the best place to look for your swimming hole?

A)a point bar on the inside bend of a meander
B)outside bend of the meander loops
C)straight stretches between meander loops
D)It isn't easy to predict,you'll just have to look around.

Question 26

________ generally constitutes the highest percentage of the annual sediment load moved by a stream.

A)Bed load
B)Dissolved load
C)Suspended load
D)Saltation load

Question 27

The single most important erosional agent is ________.

A)running water
B)wind
C)ice
D)waves

Question 28

The main power of water in a channel is related to its ________.

A)velocity and temperature
B)viscosity and velocity
C)discharge and viscosity
D)slope and discharge
E)slope and temperature

Question 29

________ make up the suspended loads of most rivers and streams.

A)Dissolved ions and sand
B)Dissolved salts
C)Silt and clay-sized,detrital grains
D)Sand and gravel that move during floods

Question 30

At a bend in a river,the main erosion is ________.

A)on the outside of the bend
B)on the inside of the bend
C)both outside and inside the bend
D)at an oxbow lake

Question 31

The Platte River crosses the Nebraska sandhills and carries little silt and clay,but moves large amounts of sand.What kind of stream would you predict from this characteristic?

A)meandering stream
B)braided stream
C)bedrock stream
D)none of the above

Question 32

Assuming rivers of comparable discharge,which type of stream would most likely be crossable by wading rather than having to swim?

A)braided stream
B)meandering stream
C)bedrock stream
D)There would be no difference.

Question 33

The Mississippi River today is a classic meandering river.20,000 years ago the Mississippi River was a major outwash channel for the Laurentide ice sheet,and was characterized by dramatic variations in flow with huge discharge during summer ice melt and a dramatic falloff in discharge during the winter.The river also carried coarser sediment than today,with abundant sand and even gravel in its upper reaches.What does this suggest about the ancient Mississippi?

A)It probably looked similar to the river today,but was characterized by more dramatic summer floods that occurred every year.
B)It probably resembled modern rivers in Alaska with a broad braided stream valley that dried up during the winter months,producing winter dust storms.
C)It was probably a lush heavily vegetated valley due to the nutrients brought down by the glacial meltwater,producing a swampy landscape with numerous channels.
D)It is impossible to predict what the river might have looked like.

Question 34

The main source of the dissolved load in a stream is ________.

A)material along the sides of the stream channel
B)material along the bottom of the stream channel
C)groundwater
D)salt flats
E)cut bank soil

Question 35

The type and amount of material carried in the suspended load of a stream depends on ________.

A)turbulence and viscosity
B)source accessibility and slope
C)ground cover and channel shape
D)flow velocity and discharge
E)settling and flow velocities

Question 36

________ describes the total sediment load transported by a stream.

A)Capacity
B)Discharge
C)Competence
D)Hydro-load factor

Question 37

As stream discharge increases ________.

A)velocity,width,and depth increase
B)only velocity increases
C)velocity,width,and depth decrease
D)only depth increases

Question 38

You are in a boat and concerned about shallow water in a meandering river.Where should you aim your boat to find the deepest water?

A)along the inside of the curve
B)midchannel
C)on the outside of the curve,close to the cut bank
D)It doesn't matter,as long as you remain a meter or two from either bank

Question 39

________ is an abandoned,cutoff,meander loop.

A)A bulltrail
B)An oxbow
C)A cowhock
D)A gatorback

Question 40

If you were to examine the profile of a typical river,you would probably find that the gradient is ________.

A)steepest near the mouth
B)steepest near the head
C)the same at both the head and mouth
D)none of these

Question 41

Which of the following is not a form of artificial flood control?

A)levee construction
B)dam construction
C)channel cutoff to form oxbow lakes during a flood
D)forced levee breaks to deflect flood waters

Question 42

Over time as erosion lowers the landscape a river valley will typically ________.

A)deepen into a bigger and bigger canyon,like the Grand Canyon
B)become steeper and discharge increases in the streams
C)become narrower but with a lower gradient,entrenching meanders
D)become broader and lower gradient

Question 43

A river is flowing in a broad,alluvial valley and the river is silt-laden but also moves sand and a small amount of gravel.The government decides to build a dam across the valley for power and flood control.What will happen to the river,upstream of the dam?

A)The river will downcut.
B)The river will start to deposit sand and gravel,frequently spilling out of its channel.
C)The river will not change.
D)The river will respond to the new temporary base level and cut laterally outside its valley,widening the valley.

Question 44

________ is the volume of voids or open space in a rock or unconsolidated material.

A)Permeability
B)Space yield
C)Porosity
D)Saturation index

Question 45

An alluvial fan ________.

A)is another name for a small delta forming along a beach
B)a fan-shaped mass of sediment deposited at the base of a mountain front due to an abrupt change in stream gradient
C)a fan-shaped sediment mass generated by a distributary channel
D)a plant that grows in deltas and is diagnostic of a delta

Question 46

A meandering river is flowing in a broad,alluvial valley and the river is silt-laden but also moves sand and a small amount of gravel.The government decides to build a dam across the valley for power and flood control.What will happen to the river downstream of the dam?

A)The river will start to deposit sand and gravel,frequently spilling out of its channel.
B)The river will not change.
C)The river will respond to the new temporary base level and cut laterally outside its valley,widening the valley.
D)The trapping of silt in the reservoir will change the river to a braided stream because it will only have sand and gravel in its sediment load.

Question 47

Downcutting (also known as rejuvenation)of a stream may be due to ________.

A)rising of sea level
B)uplift of land
C)a decreased gradient
D)thermal expansion

Question 48

Which of the following must result in a lower base level for rivers and streams?

A)sea level drops; land subsides
B)sea level falls; land rises
C)sea level rises; land subsides
D)sea level rises; land rises

Question 49

The city of New Orleans is in the delta of a great river.During hurricane Katrina most of the city flooded but the area along the river,like the French Quarter,did not.Why didn't these areas flood?

A)The army corps of engineers must have dredged the river and built these areas up before the city was built.
B)These areas were natural levees of the river,and were higher in elevation than adjacent areas.
C)The water couldn't flow fast enough to cover these areas and was halted before it could flood these areas.
D)The river flowed away from these areas into other parts of the city when it broke the levees,and these areas just happened to be spared.

Question 50

In 2011 snow melt and heavy rains in the upper Missouri River drainage basin produced record runoff that led to extensive flooding in lower Missouri River valley,despite the construction of numerous large flood control dams built on the river in the mid 20th century.What type of failure in an artificial flood control system is this an example of?

A)Insufficient levee construction downstream of the dams
B)A flood outside the design capabilities of the dam system overwhelmed the capacity of the reservoirs forcing opening of flood gates,exacerbating the downstream impact of the flooding
C)Bad planning by the water managers who cared more about power production than downstream flooding
D)It was not a failure; the dam system worked as planned.It was poor planning by the downstream government agencies.

Question 51

A natural levee is ________.

A)an erosional feature
B)a depositional feature
C)essentially parallel to its stream channel
D)both a depositional feature and essentially parallel to its stream channel

Question 52

A stream meanders across a broad,flat valley with numerous swamps and lakes.This stream is ________.

A)running well above base level
B)running at base level or below base level
C)running on bedrock
D)responding to a fall in base level

Question 53

Caves most commonly form in ________.

A)limestone
B)sandstone
C)quartzite
D)shale

Question 54

The water table is ________.

A)a boundary between unsaturated bedrock and an underground river
B)a boundary between unsaturated bedrock below and saturated bedrock above
C)an underground mass of partly saturated rock
D)a boundary between saturated rock below and unsaturated rock above

Question 55

At the head of a delta,the major channel splits into smaller channels that follow different paths to the sea.These smaller channels are known as ________.

A)endotributaries
B)exotributaries
C)distributaries
D)cotributaries

Question 56

A river emerges from a valley onto a flat plain,but the river itself lies in a narrow,shallow canyon as it crosses the plain,then plunges into a steep sided canyon as it flow past the plain.A geologist floating down the canyon headed for the whitewater in the canyon notices the river is flowing through lake deposits as it flows across the plain.What happened in this area?

A)The river is at base level throughout its trace and has been for a long time.
B)The river used to flow into a lake,which formed a temporary base level,but in recent geologic time the lakes dam broke,and the river is now downcutting in response to the change in local base level.
C)The river has cut a deep canyon that crossed through a lake,and this process has been continuous for a long time.
D)The geologist can't be right; this is an impossible scenario.

Question 57

Which of the following features characterize meandering streams and valleys?

A)natural levees; broad floodplains
B)rapids; channel bed potholes
C)waterfalls; entrenched meanders
D)V-shaped valley cross sections

Question 58

When a stream is in a v-shaped valley running on bedrock,the stream is ________.

A)well above base level
B)at base level
C)below base level
D)responding to a rise in base level

Question 59

Permeable rock strata or sediment that transmit groundwater freely are called ________.

A)perched water tables
B)aquitards
C)springs
D)aquifers

Question 60

A ________ flood occurs when heavy rain strikes a mountainous area.

A)regional
B)flash
C)monsoon
D)quick

Question 61

________ would have the largest capacity to naturally remove sewage pollutants.

A)Fractured granite
B)Well-sorted,coarse gravel
C)Slightly clayey sand
D)Limestone with solution channels and caverns

Question 62

When water is pumped from a well,a depression is often produced in the water table.Such a depression is a(n)________.

A)perched water table
B)pumping dimple
C)cone of depression
D)artesian well

Question 63

Hot springs are most numerous in which region of the United States?

A)Southeast
B)Midwest
C)West
D)Northeast

Question 64

Which of the following best describes how geysers erupt?

A)Water suddenly boils in disconnected voids and cracks above the water table,causing the aquifer to explosively fragment.
B)Water slowly boils in a network of vertical cracks above the water table,sending up a plume of steam and hot water.
C)Water below the water table slowly boils in a vertical crack or natural conduit,causing a plume of condensed water vapor to rise above the vent.
D)With a slight reduction in pressure,water in a saturated,natural conduit suddenly boils,sending a plume of steam and hot water into the air above the vent.

Question 65

The term karst topography was first used in ________.

A)the Republic of Slovenia,a province of the former Yugoslavia
B)eastern Canada in areas of fractured igneous and metamorphic rocks
C)India,near the southern foothills of the Himalayan Mountains
D)Australia for the extremely dry interior area near Ayres Rock and Alice Springs

Question 66

A small town in New Mexico discovers that a chemical plant outside of town recently learned that one of their underground pipelines had broken without their knowledge and had been leaking a toxic organic compound for over a month.The spill occurred 5m below the surface in a sandstone above a thin shale bed in the local bedrock.The beds are flat lying and this shale crops out 200m from the chemical plant.The town gets is water from deep wells,about 300m deep.What should the town worry about from this spill?

A)There is an immediate threat of contamination of the city water supply.
B)There is a threat by the company to move because they do not want to clean up the damage.
C)There is no immediate worry,but in the long term their city water will almost certainly be contaminated.
D)There is no threat to the city water,but there is a likely health threat when the chemical moves to the surface outcrops of the layers the spill occurred in.

Question 67

gradient velocity capacity discharge

Question 68

Bed load Cap load Dissolved load Suspended load

Question 69

Which one of the following concerning artesian wells is not true?

A)The well penetrates an aquifer overlain by an aquitard.
B)The well penetrates an aquifer underlain by an impermeable bed.
C)The aquifer is generally inclined,and it is saturated to an elevation above the point where the well penetrates the aquifer.
D)When the well penetrates the aquifer,the water rises to the bottom of the aquitard above the aquifer.

Question 70

artificial levees dams floodplains channelization

Question 71

Farmer Brown lives in a semi-arid part of the United States with numerous small lakes associated with glacial deposits of sand and gravel.He decides he needs to irrigate part of his land and drills a shallow well 100m from his property line with Farmer Smith who has a small lake just across the property line,and he depends on this lake to water his cattle.By late summer,Farmer Smith goes out to his lake and discovers it is dry.What happened?

A)Farmer Brown's well produced a sinkhole that swallowed up Farmer Smith's lake.
B)There must have been a drought or Farmer Brown wouldn't have needed to irrigate,so it must be natural.
C)Farmer Brown has been secretly pumping water from Farmer Smith's lake,and now Farmer Smith is going to come out at night with a shotgun.
D)Farmer Browns well has dropped the water table in the well's cone of depression,and the well has led to the lake drying up.

Question 72

An artesian well is one in which ________.

A)the water is warm,fairly saline,and recharged by an affluent stream
B)pressurized groundwater rises from a deep,unsaturated aquifer
C)water rises above the top of the aquifer without any pumping
D)the well is horizontal and the water table is perched

Question 73

porosity permeability aquitard aquifer

Question 74

Much of the city of New Orleans is below sea level,yet it was not an ocean when the city was first settled.How did it get below sea level?

A)Drainage canals and groundwater withdrawal produced subsidence that dropped the land below sea level.
B)The area was dredged to build levees,and so it was left below sea level.
C)Oil production withdrew oil and produced land subsidence.
D)Sea level is just rising.

Question 75

stalagmite soda straw sinkhole stalactite

Question 76

In the canyonlands of Utah and Arizona,canyon walls often support "hanging gardens" in which plants cling to sandstone cliffs and these hanging gardens are typically along shale beds in the sandstone.These areas are deserts,so what might explain these features?

A)The shales hold the water better than the sandstone,so plants preferentially grow in them.
B)The shales form better soils than the sand,so the plants grow there.
C)The shales form aquitards in the sandstone acquifer,trapping groundwater along the shale horizons that helps aid plant growth.
D)The shales are more fractured than the sandstones so the plants have an easier time starting in the shale.

Question 77

Which of the following is associated with areas of karst topography?

A)sinkholes
B)soluble rock
C)caverns
D)all of these

Question 78

A ________ is the icicle-like speleothem that grows down from the roof of a cavern.

A)stalandite
B)stalactite
C)stalagmite
D)slagdite

Question 79

Sinkholes and karst topography are a clear indication that ________.

A)the groundwater is moving through cracks in the rock
B)the groundwater is moving through a limestone and forming caves that periodically collapse
C)the area has been subjected to past meteorite bombardments and groundwater is moving through the fractured rock
D)there is nothing unusual; these features occur everywhere there is fast motion of groundwater in the subsurface

Question 80

cut bank point bar natural levee delta