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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.
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BIG Idea: • Surface water moves materials produced by weathering and shapes the surface of Earth.
rivers lakes streams ponds seas
rain ice snow under the ground
under the ground into the ocean evaporates into the sky
I. THE WATER CYCLE (Hydrologic Cycle) • EVAPORATION: liquid water changes to water vapor (gas)
EVAPOTRANSPIRATION: combined processes of evaporation and transpiration
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
1 of the 3 major regional watersheds of VA 15 million people live within the area covers over 64,000 square miles Chesapeake Watershed
Where do the 3 major regional watershed systems in VA lead? • Chesapeake Bay • North Carolina Sounds • Gulf of Mexico
A. STREAM EROSION • CHANNEL:The path that a stream follows
STREAM LOAD: materials carried by a stream Larger materials scrape along river sides and bottom along river bottom Fine sand and silt; speed keeps particles suspended (not sinking to 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
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