Surface Water

BIG Idea: Surface water moves materials produced by weathering and shapes the surface of Earth.

What types of bodies of water constitute surface water?

rivers lakes streams ponds seas

From where does surface water come?

rain ice snow under the ground

Where does surface water go?

under the ground into the ocean evaporates into the sky

I. THE WATER CYCLE (Hydrologic Cycle) EVAPORATION: liquid water changes to water vapor (gas)

TRANSPIRATION: plants give off water vapor into the air

EVAPOTRANSPIRATION: combined processes of evaporation and transpiration

CONDENSATION: change from water vapor to liquid water

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

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

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

FACTORS THAT AFFECT RUNOFF: soil composition rate of precipitation vegetation slope

A. Water Budget The water budget is like a financial budget… You want both to be balanced.

precipitation is the income evapotranspiration and runoff are the expenses

II. RIVER SYSTEMS Made up of a main stream and all the feeder streams that flow into it Tributaries: feeder streams for rivers

Watershed: area of land that drains into a lake, river or stream Also known as the Drainage Basin

Chesapeake Watershed 1 of the 3 major regional watersheds of VA 15 million people live within the area covers over 64,000 square miles

Where do the 3 major regional watershed systems in VA lead? Chesapeake Bay North Carolina Sounds Gulf of Mexico

CHANNEL: The path that a stream follows A. STREAM EROSION CHANNEL: The path that a stream follows

STREAM LOAD: materials carried by a stream Fine sand and silt; speed keeps particles suspended (not sinking to river bottom) Larger materials scrape along river sides and bottom along river bottom Short jumps made by bed load if the river is moving fast enough

Ways that sediments are carried in a stream: Bed Load Solution Suspension

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

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

Solution Materials dissolved in a stream’s water.

Suspension Particles small enough to be held up by the stream’s moving water.

DISCHARGE: volume of moved water by a stream at a given time

The faster the stream flows… The higher its discharge… The greater the load it can carry

Gradient: steepness of the slope the stream is flowing down The gradient is steepest near the headwaters (beginning of the stream)

B. STAGES OF A RIVER SYSTEM Mature and Old Youthful Rejuvenated

1. YOUTHFUL RIVERS “V” shaped valley with steep sides waterfalls and rapids few tributaries small volume of water

2. MATURE RIVERS many tributaries high volume of water erosion occurs along widening valley walls and during floods

a. MEANDERS: series of wide curves

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

3. OLD RIVER low gradient with slow flow no longer erodes land starts to fill itself in with sediment

4. REJUVENATED RIVER gradient of a river becomes steeper due to tectonic activity

Is this river young, old, or middle aged?

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

How sediments are deposited

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

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

C. Flood Deposits 1. Flood Plain: part of the valley that may be covered with water during a flood.

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

IV. Glaciers large, moving masses of ice form: near Earth’s poles and in mountainous areas at high elevations cover about 10% of Earth’s surface

Two Types: formed in mountainous areas long narrow wedge of moving ice 1. Valley Glacier: formed in mountainous areas long narrow wedge of moving ice

Erode a U-shaped valley

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

Glacial Till: unsorted rock, gravel, sand, and clay that glaciers carry and deposit Moraine: unsorted ridges of till left behind when the glacier melts

Glacial Striations in Central Park, NY

Glacial Erratic in Central Park, NY (Pegmatite)