Geology Quiz 4- Streams

Occurs when a stream exceeds channel capacity

Flooding

Concentrated flows of water in channels

Streams and rivers

Stream flow begins as

Scattered runoff

Tributaries

Small streams

Trunks

Large streams

Tributaries join together to form...

Trunks

Configuration of _____ and _____ defines the drainage network

Tributaries; Trunk

Area of land that drains into a stream

Watershed

Ridges and peaks separate

drainage basins

What drainage pattern is this?

Parallel

Defining factor of parallel drainage patterns

Parallel streams

What drainage pattern is this?

Dendritic

Defining factor of dendritic drainage patterns

Irregular branching

What drainage pattern is this?

Radial

Defining factor of radial drainage patterns

Outward from a central peak

What drainage pattern is this?

Rectangular

Defining factor of rectangular drainage patterns

90-degree bends

What drainage pattern is this?

Trellis

Defining factor of trellis drainage patterns

Nearly parallel, joined by short perpendicular streams

Separates drainages that flow to different water bodies

Continental divides

The amount of water flowing in a channel

Discharge

Discharge equation

Area*velocity

Twisting, swirling motion of a fluid

Turbulence

Velocity of turbulent water

Uneven velocity

Irregularities in the bank and bottom cause...

turbulance

Objects in the water cause...

turbulance

Steep gradients in streams cause...

turbulance

Turbulence helps to...

breaks, abrades, and dissolves materials

Turbulent water picks up and moves sediment is called....

scouring

Turbulent water that rapidly moves water is called...

breaking and lifting

The "sandblasting" of rock by particles moving in fast-moving water is called..

abrasion

Gravel swirling makes potholes into bedrock through...

abrasion

Running water that dissolves soluble minerals is called...

dissolution

The material moved by running water load is called...

sediment load

Ions from chemical weathering are this kind of sediment load...

dissolved loads

Fine particles (silt and clay) in the water are this kind of sediment load...

Suspended load

Large particles roll, slide, and bounce along the bottom are this kind of sediment load...

Bed load

The maximum clast size transported is...

competence

The total quantity of sediment carried is...

capacity

Capacity and competence change with...

discharge

High discharge moves what kind of sediments?

Large cobbles and boulders

Low discharge moves what kind of sediments?

Smaller grains

Deposits that are transported by streams

Fluvial deposits

Common term for stream sediments

Alluvium

Source of the stream

Headwaters

Gradient near the headwaters

Steep

Discharge near the headwaters

Low

Competence (max sediment size) near the headwaters

high/course

Channel shape near the headwaters

straight

Lowest elevation of a channel

Base level

Gradient near the base level

Nearly flat

Discharge near the base level

High

Competence (max sediment size) near base level

Low/fine

Channel shape near base level

Meandering

Stream gradient equation

Change in elevation/

change distance

Describes the changes in a streams channel's elevation from mouth to headwater

Longitudinal profile

Velocity at base level

zero

Ultimate base level

sea level

Temporary base level example

Lake, ledge of hard rock (waterfall), rapids

Turbulent flow of water causes...

rapids

Steep gradient and/or high friction results in...

rapids

When base level rises/drops it creates...

terreces

Raised base level, slow flow, more sediment is a....

valley

Lower base level, quick flow, less sediment is...

canyon

Stream terraces mark former...

floodplains

What kind of channel morphology is this?

Braided stream

Sediment load in a braided stream is..

very high

Channel level in a braided stream is...

very shallow

Braided streams occur after...

flooding

What kind of channel morphology is this?

Meandering Streams

Gradient in a meandering stream

Low

Streams with sinuous, looping curves

Meandering streams

Meandering streams evolve during...

flooding

Floodplains are bounded by...

bluffs

Ridge formations that are parallel to the channel

Natural levees

Water overflowing the channel onto adjacent land

Floodplain

Floods that occur during "wet season"

Seasonal floods

Wet season examples

Heavy precipitation, monsoon season, snow melt

Water rises rapidly with little warning

Flash floods

Intense rainfall or dam failure causes...

flash floods

Average number of year between floods of a particular size

Recurrence interval

Two types of walls to prevent overflow of floodplains

Man-made levees, flood walls

Artificial lakes that store excess water and release it in a controlled manner

Flood control reservior

Area of woodlands helps to slow down runoff and absorb more water

Reforestation

Areas of low or no development that are allowed to flood

Floodways