Quiz 10: Streams and Floods

The interrelationship of the hydrosphere, geosphere, biosphere, and atmosphere is visualized through the hydrogeologic cycle.

Sheetwash is a thin layer of unchanneled water flowing downhill.

Drainage basins are bowl-shaped depressions with a lake in the middle, and all streams in the basin discharge their water and sediment into that lake.

A trellis stream pattern consists of parallel main streams with short tributaries meeting them at right angles.

Stream erosion and deposition are controlled primarily by a river's velocity.

Low stream velocity generally results in erosion and transportation of sediment.

Stream discharge is one of the most important factors that controls stream velocity.

Hydraulic action refers to the ability of flowing water to pick up and move rock and sediment.

A stream reaches its maximum velocity close to the shoreline.

The discharge of a stream is the volume of water that passes a given point in unit of time (for example, 50 cubic meters per second).

A bar in a river channel is a ridge of sediment, usually sand and gravel, deposited in the middle or along the banks of a stream.

Saltation of sand grains begins when they are dissolved.

Braided streams flow in a network of interconnected rivulets around numerous bars.

Point bars are sandbars deposited in the middle of river channels.

A cutoff meander can become an oxbow lake.

Stream-dominated river deltas, like the Mississippi, display the characteristic triangular shape of a delta.

An alluvial fan is a fan- or cone-shaped pile of sediment that forms where a stream emerges from a narrow mountain canyon.

The process of deepening a valley by erosion of the streambed is called downcutting.

Paved areas and storm sewers decrease the rate of surface runoff of water.

A stream can lengthen its valley by headward erosion.

The gravel bed load of a stream moves by _____. A) dissolution B) solution C) suspension D) sliding and rolling E) flotation

________ are low ridges of flood-deposited sediment that form on both sides of a stream channel and thin away from the channel. A) Point bars B) Natural levees C) Oxbows D) Cut banks E) Deltas

The movement and interchange of water between the sea, air and land can be visualized by the ____. A) longitudinal profile of a stream B) channelization procedures C) hydrologic cycle D) hydrosphere interactions such as precipitation E) solar radiation

A(n) ___ stream flows in a network of rivulets (subchannels) around numerous sandbars. A) braided B) meandering C) incised D) channelized E) rilled

A stream can increase its length by _____. A) building a delta B) meandering C) headward erosion D) All of the answers are correct.

A ridge or strip of ground separating one drainage basin from another is termed a ____. A) delta B) neck C) crest D) plateau E) divide

Certain features on the planet Mars resemble _____ on Earth. A) river channels B) hydrologic cycle C) alluvial fans D) deltas E) placer deposits

A(n) __ is the body of sediment deposited at the mouth of a river when the river's velocity decreases. A) apron B) alluvial fan C) bar D) delta E) wart

A "100-year flood" has a _______ percent chance of occurring in any given year. A) 1 B) 100 C) 10 D) 0.1 E) 0.01

Rivers may develop pronounced sinuous (wiggly) curves called a ___ pattern. A) braided B) meandering C) incised D) channelized E) rilled

A cutoff meander may become a crescent-shaped __. A) kettle lake B) moraine lake C) levee lake D) oxbow lake E) Yazoo lake

A _____ is a ridge of sediment built by sedimentation on the middle or banks of a stream channel. A) levee B) flood plain C) meander loop D) channel E) bar

The ______ is the total area drained by a river and its tributaries. A) flow area B) divide C) drainage basin D) domain E) hood

A stream's discharge is __. A) the volume of dissolved mineral matter carried by the stream in a unit of time B) the volume of solid sediment carried by the stream in a unit of time C) the volume of water passing through a specific point along the stream in a unit of time. D) the volume of excess water during flood stage E) the average amount of water in the entire stream system

Movement of cobbles and boulders by rolling, sliding, or dragging in a streambed is called ____ load. A) dissolution B) solution C) suspension D) traction E) saltation

The limit to downcutting of a stream is called the ___ level. A) head B) base C) flow D) stream E) foot

A ____ drainage pattern is one in which streams diverge outward likes spokes on a wheel. A) jointed B) tilted C) compass D) radial E) conical

In North America, the ___ separates streams that flow into the Pacific Ocean from those that flow into the Atlantic Ocean and Gulf of Mexico. A) Appalachian Mountain Range B) Mississippi River C) Continental Transect D) Sierra Nevada Mountain Range E) Continental Divide

_____ are low ridges of flood deposited sediment that form on either side of a stream channel and thin away from the channel. A) Point bars B) Natural levees C) Incised meanders D) Deltas E) Oxbow lakes

___ influences the velocity of a river along with gradient. A) Direction of flow B) Channel shape and roughness C) Temperature of the water D) Chemistry of the water E) Latitude of the river

A river's velocity is faster ____. A) along the inside of a meander loop near the point bar B) along the center line of the stream channel, exactly halfway between point bar and cut bank C) along the outside of a meander loop near the cut bank D) at the water's surface, in contact with the atmosphere E) along the channel bed at the very deepest part of the channel

A stream can lengthen itself by ____. A) headward erosion B) deposition of a delta C) meander-loop cut-off D) stream discharge E) Headward erosion and deposition of a delta are both correct, but meander-loop cut-off and stream discharge are incorrect.

The ______ load is sediment light enough to remain lifted indefinitely above the bottom by water turbulence. A) dissolution B) solution C) saltation D) suspension E) segregation

The delta of the ______ River is a wave-dominated delta that resembles the Greek letter delta and is the origin of the name. A) Mississippi B) Nile C) Amazon D) Colorado E) Ganges

_____ refers to sand grain movement in a series of short leaps or bounces off the bottom. A) Jumping B) Floating C) Saltation D) Hopping E) Vaulting

_____ meanders are meanders that retain their sinuous pattern as they cut vertically downward below the level at which they originally formed. A) Incised B) Excised C) Excavated D) Concentrated E) Superposed

A graded stream can be deepening its channel by down cutting while part of its energy is also widening its valley by ______ erosion. A) downward B) longitudinal C) lateral D) distal E) proximal

A(n) ___ is a step-like landform found above a stream and its floodplain. It is a remnant of an older flood plain or river-eroded flat surface. A) levee B) incised meander C) cut bank D) stream terrace E) upland plateau

A(n) ____ stream is one that exhibits a delicate balance between its transporting capacity and the sediment load available to it. A) graded B) ephemeral C) consequent D) incised E) beheaded

Flood control structures along the Mississippi River surrounding New Orleans are predominantly _____. A) upstream dams B) riprap lining C) bypasses D) artificial levees E) All of the answers are correct.

The process of deepening of a valley by erosion of a streambed is called __. A) lateral erosion B) down cutting C) faulting D) aggradation E) subsidence

A(n) ___ drainage pattern of a river resembles a tree. A) dendritic B) trellis C) bush D) arbor E) leaf

___ is/are sudden localized floods of large volume and short duration, often triggered by heavy rainstorms. A) Sheetwash B) Dry flooding C) Flash floods D) Channel erosion E) Stream piracy

_______ deposits are found in streams where running water has mechanically concentrated heavy sediment such as gold. A) Placer B) Lag C) Granular D) Pebble E) Agglomerated

Streams erode rock and sediment by ___. A) hydraulic action B) solution C) abrasion D) All answers are correct. E) None of the answers are correct.

On large alluvial fans, the _____ sediment is deposited near the mountains. A) finest B) clay C) coarsest D) quartz E) best sorted

Floods are described by ____, the average time between floods of a given size. A) discharge B) forecasting C) calendar year D) recurrence interval E) lunar month

Deltas may be river dominated, tide dominated or _____. A) tsunami dominated B) wave dominated C) glacier dominated D) wind dominated E) plate tectonic dominated

___ beds form the main body of a delta with angles of inclination up to 20 to 35 degrees in small sandy deltas. A) Turbidite B) Foreset C) Backset D) Bottomset E) Topset

Discharge is the product of average stream width times average stream depth times ___. A) stream velocity B) stream sinuosity C) stream elevation D) stream gradient E) stream temperature