The Flow of Fresh Water Chapter 11. 11-1 The Active River Water Cycle Erosion The removal and transport of surface material Can occur from wind, rain,

The Flow of Fresh Water

Chapter 11

11-1 The Active RiverWater Cycle

ErosionThe removal and

transport of surface material

Can occur from wind, rain, ice, and snow

Cause of the Grand Canyon and MN’s lakes

11-1 The Active RiverWater Cycle

The continuous movement of water from water sources

Lakes/OceansAir LandInto Ground Lakes/Oceans

EvaporationOccurs when liquid water from the Earth’s surface and from

living organisms changes into water vaporCondensation

Occurs when water vapor cools and changes into liquid water droplets that form clouds in the atmosphere

PrecipitationRain, snow, sleet, or hail that falls from clouds onto the

Earth’s surface

11-1 The Active RiverWater Cycles

RunoffWater that flows across land and collects in rivers,

streams, and eventually the oceanInfiltration

The movement of water into the ground due to the pull of gravity

PercolationThe downward movement of water through pores

and other spaces in soil due to gravity

11-1 The Active River

11-1 The Active RiverRiver Systems

TributariesSmaller streams or

rivers that flow into larger ones

Make up a network to drain and area of land

11-1 The Active RiverRiver Systems

Drainage BasinsThe land drained by

a river systemIncludes the main

river and all tributaries

U.S.’s main basin is the MississippiExtends from the

Rocky Mts. to Appalachian Mts.

11-1 The Active RiverRiver Systems

DividesSeparates drainage

basinsUsually an area of

higher ground than the basin it separates

11-1 The Active RiverStream Erosion

ChannelThe path that a

stream followsStart out small and

steepBecomes wider and

deeper the longer they go

11-1 The Active RiverStream Erosion

GradientThe measure of the

change in elevation over a certain distance

High gradient has more energy to erode rock and soil

(Elevation)/(Distance)= Gradient

11-1 The Active RiverIf a river starts at an elevation of 4,900

meters and travels 450 km downstream to a lake that is at an elevation of 400 meters, what is the stream’s gradient?

4,900 m – 400 m = 4,500 m4,500 m / 450km = 10 m/km

11-1 The Active RiverStream Erosion

DischargeAmount of water a

stream or river carries in a given amount of time

With an increase, the energy, speed, and load increases

11-1 The Active RiverStream Erosion

LoadMaterials carried in a stream’s waterAffected by the stream’s speed

Faster the speed the larger the loadBed Load

Large materials like pebbles and boulders

11-1 The Active RiverStream Erosion

LoadSuspended Load

Small rocks and soil in suspensionCauses river to look muddy

Dissolved LoadMaterials dissolved in the water

11-1 The Active RiverStages of a River

Youthful RiversErodes its channel

deeper rather than wider

Water flows quicklySides of channel are

steep and straightFew tributaries

11-1 The Active RiverStages of a River

Mature RiversErodes its channel

wider rather than deeper

Gradient is not as steep as a youthful river

Fewer falls and rapidsFed by many

tributariesHas more discharge

than a younger river

11-1 The Active RiverStages of a River

Old RiversLow gradientLow erosive powerDeposits sediments

in its channelHas wide flood plainsHas fewer tributaries

than a mature river because tributaries have merged

11-1 The Active RiverStages of a River

Rejuvenated RiversOccur where the land

is raised by tectonic forcesSteepens the

gradientTerraces often

form on both sides of the stream valley

11-2 Stream and River DepositsDeposition

Process by which material is dropped or settles out of a solution

Soils and rocks drop out of rivers and deposit in the river bed

Will change the shape of the river

11-2 Stream and River DepositsDeposition in Water

AlluviumRock and soil

deposited by streams

Occurs at places where the speed of the current decreases

Placer DepositWhere heavy

minerals, like gold, are deposited

11-2 Stream and River DepositsDelta

A fan shaped deposit at the end of a river

Occurs where the river enters a large body of water

11-2 Stream and River DepositsDeposition on Land

Alluvial FanOccurs where

alluvium meets a flat plain

A fan shaped deposit that is on dry land

Flood PlainThe land that an over

flowing river will coverWill leave a layer of

alluviumVery fertile soils

11-3 Water UndergroundGround Water

Water located within the rocks below the Earth’s surface

Zone of AerationUsually filled with

water only after a rain storm

Zone of SaturationWhere water

accumulates in spaces between rock particles

11-3 Water UndergroundGround Water

Water TableUnderground

boundary where the two zones meet

Rises during wet seasons

Drops during dry seasons

11-3 Water UndergroundAquifers

A rock layer that stores and allows a flow of ground water

PorosityThe amount of open

space between individual rock particles

Aquifer must be porousPermeability

Rock’s ability to let water pass through it

11-3 Water UndergroundAquifers

Best are formed of sandstone, limestone, or layers of sand and gravel

Cover large underground areas

Important source of water for cities and agriculture

11-3 Water UndergroundAquifers

Recharge zonesGround surface

where water enters an aquifer

Restricted to areas where the rock is permeable

Depend of the water cycle to maintain a constant flow of water

11-3 Water UndergroundSprings

Where water will flow out of the ground

Important source of drinking water

Artesian SpringSprings that form

where cracks occur naturally in the cap rock

Pressurized water in the aquifer flows through cracks to the surface

11-3 Water UndergroundWells

A human made hole that is deeper than the level of the water table

Will dry up if…It is not below the

top of the water table during the dry season

If to much water is taken to fast

11-3 Water UndergroundUnderground

FormationsCave formations

Formed by erosion and deposition

DripstoneWater that drips from

cracks in a cave’s ceiling

Composed of limestone

Stalactiteso Build from the

ceiling downStalagmites

o Build from the floor up

11-3 Water UndergroundUnderground

FormationsSinkholes

When a cave collapses and the surface ground falls in

Can form lakes or swamps

11-4 Using Water WiselyWater Pollution

Nonpoint Sourcedoesn’t come from one

sourcestreet gutters,

fertilizers, and eroded soils

Point SourceComes from one

particular sourceSewer pipes or factory

drains

11-4 Using Water WiselyCleaning Water

Sewage treatment plants Factories that clean the

waste materials out of water

Primary Treatment Solid objects are

removed using screens Small particles sink to

the bottom Secondary Treatment

Water is mixed with oxygen and bacteria

Chlorine is added to disinfect

Water is released