Surface WaterSurface Water

BIGBIG Idea: Idea:

•Surface water moves Surface water moves materials produced by materials produced by weathering and shapes the weathering and shapes the surface of surface of Earth. Earth.

•What types of bodies of What types of bodies of water constitute water constitute surfacesurface water?water?

•riversrivers

•lakes lakes

•streamsstreams

•pondsponds

•seasseas

•From where does surface From where does surface water come?water come?

•rainrain

•iceice

•snowsnow

•under the groundunder the ground

•Where does surface water Where does surface water go?go?

•under the groundunder the ground

•into the oceaninto the ocean

•evaporates into the skyevaporates into the sky

II. . THE WATER CYCLE THE WATER CYCLE ((Hydrologic CycleHydrologic Cycle))

•EVAPORATION: EVAPORATION: liquid water liquid water changes to water vapor changes to water vapor (gas)(gas)

•TRANSPIRATION: TRANSPIRATION: plants plants give off water vapor into give off water vapor into the airthe air

•EVAPOTRANSPIRATION: EVAPOTRANSPIRATION: combined processes of combined processes of evaporation and evaporation and transpirationtranspiration

•CONDENSATION: CONDENSATION: change from water vapor change from water vapor to liquid waterto liquid water

•SUBLIMATION: SUBLIMATION: ice ice slowly changes to gas slowly changes to gas without first entering a without first entering a liquid stateliquid state

•PRECIPITATION:PRECIPITATION: water water falls from clouds to falls from clouds to Earth’s surface (in the Earth’s surface (in the form of rain, snow, sleet, form of rain, snow, sleet, hail)hail)

•RUNOFF: RUNOFF: water that water that flows over the land into flows over the land into streams and riversstreams and rivers

http://www.3valleys.co.uk/popups/watercycle.htm

FACTORS THAT AFFECT FACTORS THAT AFFECT RUNOFF:RUNOFF:

•soil compositionsoil composition

•rate of precipitationrate of precipitation

•vegetationvegetation

•slopeslope

A. Water BudgetA. Water Budget

•The water budget is like a The water budget is like a financial budget… financial budget…

•You want both to be You want both to be balanced.balanced.

•precipitation is the incomeprecipitation is the income

•evapotranspiration and evapotranspiration and runoff are the expensesrunoff are the expenses

II. RIVER SYSTEMSII. RIVER SYSTEMS

• Made up of a Made up of a main stream main stream and all the and all the feeder streamsfeeder streams that flow into itthat flow into it

• Tributaries:Tributaries: feeder streams feeder streams for riversfor rivers

•Watershed: Watershed: area of land that area of land that drains into a lake, river or drains into a lake, river or streamstream

•Also known as the Also known as the Drainage Drainage BasinBasin

• 1 of the 3 major 1 of the 3 major regional regional watersheds of watersheds of VAVA

• 15 million 15 million

people livepeople live

within the areawithin the area

• covers over covers over

64,000 square64,000 square

milesmiles

Chesapeake Watershed

Where do the 3 major Where do the 3 major regional watershed regional watershed systems in VA lead?systems in VA lead?

Chesapeake BayChesapeake BayNorth Carolina SoundsNorth Carolina SoundsGulf of MexicoGulf of Mexico

A. STREAM A. STREAM EROSIONEROSION

•CHANNEL:CHANNEL: The path that a The path that a stream followsstream follows

STREAM LOAD: STREAM LOAD: mmaterials carried aterials carried by a streamby a stream

Short jumps made by bed load if the river is moving fast enough

Fine sand and silt; speed keeps particles suspended (not sinking to river bottom)

Larger materials scrape along river sides and bottom along river bottom

Ways that sediments are Ways that sediments are carried in a stream:carried in a stream:

•Bed LoadBed Load

•SolutionSolution

•SuspensionSuspension

Bed LoadBed Load

•Large, heavy sediments Large, heavy sediments are pushed or rolled are pushed or rolled along the bottom of a along the bottom of a stream’s bedstream’s bed..

SaltationSaltation: Short jumps made by bed load if the river is moving fast enough.

SolutionSolution

•Materials dissolved in a Materials dissolved in a stream’s water.stream’s water.

SuspensionSuspension

•Particles small enough Particles small enough to be held up by the to be held up by the stream’s stream’s movingmoving water. water.

•DISCHARGE: DISCHARGE: volume of volume of moved water moved water by a streamby a stream

at a given at a given timetime

•The The fasterfaster the stream the stream flows…flows…

•The The higherhigher its discharge… its discharge…

•The The greatergreater the load it can the load it can carrycarry

•Gradient: Gradient: steepness of the steepness of the slope the stream is slope the stream is flowing downflowing down

•The gradient is steepest The gradient is steepest near the near the headwatersheadwaters (beginning of the stream)(beginning of the stream)

B. STAGES OF A RIVER B. STAGES OF A RIVER SYSTEMSYSTEM

Youthful

Mature and Old

Rejuvenated

1. YOUTHFUL RIVERS1. YOUTHFUL RIVERS

• ““V” shaped valley with steep sidesV” shaped valley with steep sides

• waterfalls and rapids waterfalls and rapids

• few tributariesfew tributaries

• small volume of watersmall volume of water

2. MATURE RIVERS2. MATURE RIVERS

•many tributaries many tributaries

•high volume of water high volume of water

•erosion occurs along widening erosion occurs along widening valley walls and during floodsvalley walls and during floods

a. MEANDERS: a. MEANDERS: series of wide curves

b. OXBOW LAKES:b. OXBOW LAKES: closed off meander isolated away from the main part of the river

3. OLD RIVER3. OLD RIVER

•low gradient with slow flow

•no longer erodes land •starts to fill itself in with

sediment

4. REJUVENATED RIVER4. REJUVENATED RIVER

•gradient of a river becomes steeper due to tectonic activity

Is this river young, old, or middle aged?

III. STREAM DEPOSITIONIII. STREAM DEPOSITION

•Deposition:Deposition: the process by the process by which Earth materials carried which Earth materials carried by wind, water, or ice settle by wind, water, or ice settle out and are deposited (like out and are deposited (like money in the bank)money in the bank)

• How sediments are depositedHow sediments are deposited

A. Delta: A. Delta: fan shaped deposit at the mouth of a stream

B. Alluvial Fan: B. Alluvial Fan: delta on land delta on land due to the rapid reduction of a due to the rapid reduction of a stream.stream.

C. Flood DepositsC. Flood Deposits1. Flood Plain: 1. Flood Plain: part of the part of the

valley that may be covered valley that may be covered with water with water during a during a flood. flood.

2. Natural Levees: 2. Natural Levees: raised raised riverbank that results when a riverbank that results when a river floods.river floods.

IV. GlaciersIV. Glaciers

large, moving masses large, moving masses of ice of ice

form: form: – near Earth’s poles andnear Earth’s poles and– in mountainous in mountainous

areas at high areas at high elevationselevations

cover about 10% cover about 10% of Earth’s surface of Earth’s surface

Two Types:Two Types:1. 1. Valley Glacier:Valley Glacier:

formed in mountainous formed in mountainous areasareas

long narrow wedge of long narrow wedge of moving icemoving ice

Erode a Erode a UU-shaped -shaped valleyvalley

2. 2. Continental Glacier: Continental Glacier: cover cover millions of square miles (only millions of square miles (only found on Greenland and found on Greenland and Antarctica)Antarctica)

Glacial TillGlacial Till: unsorted rock, : unsorted rock, gravel, sand, and clay that gravel, sand, and clay that glaciers carry and depositglaciers carry and deposit

• MoraineMoraine: unsorted ridges of till : unsorted ridges of till left behind when the glacier left behind when the glacier meltsmelts

Glacial Striations in Central Park, NY

Glacial Erratic in Central Park, NY (Pegmatite)