3/5/12 Water Cycle
—  What is the Water (Hydrologic) Cycle?
Water
—  Movement of water on, below, and above the Earth’s
surface
—  Water changes state
—  Solid, Liquid, and Gas
—  What are the different stages of the Water Cycle?
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Water Cycle
Evaporation
Condensation
Precipitation
Run off
Infiltration
Water Cycle
—  Evaporation
—
—
—
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Infiltration vs. Runoff
—  Vegetation
—  Lots of veg.
—  More infiltration
—  Little veg.
—  More runoff
—  Rate of Precip
—  Short bursts of rain
—  More runoff
—  Light long lasting rain
—  More infiltration
—  Water changing to water vapor
—  Liquid to gas
Condensation
—  Water vapor changing to water
—  Gas to liquid
—  Condenses to dust
—  Forms clouds
Precipitation
—  Rain droplets grow bigger
—  Then fall
Run off
—  Streams and rivers
Infiltration
—  Water seeps into ground
Infiltration vs. Runoff
—  Soil Comp.
—  Clay
—  Less porous (space)
—  More runoff
—  Sand
—  More porous (space)
—  More infiltration
—  Slope
—  Shallow
—  More infiltration
—  Steep
—  More runoff
1 3/5/12 What drives the Water Cycle
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Surface Water
—  Rivers and Streams
—  Tributaries
—  Streams that flow into
larger streams
—  Watershed
—  All of the land area where
water drains into a river
system
—  Divides
—  High land area that
separates watersheds
Surface Water
—  Stream Load
—  All the material that
the water in a stream
carries
—  3 ways material is
carried
—  Solution
—  Material dissolved in
water
—  Suspension
—  Particles small
enough to be carried
by turbulence
—  Bedload
—  Large sediments that
roll along the bottom
Surface Water
Surface Water
—  Velocity (speed) and Size
—  Streams load overtime
of Sediments
—  The higher the velocity
—  Rocks become polished
and rounded
the…
—  larger the sediments
—  Larger/Faster rivers can
carry more and larger
sediments
2 3/5/12 Surface Water
Surface Water
—  Discharge
—  What causes flooding?
—  Measure of the volume of
stream water that flows past a
point for a certain time
—  Carrying capacity
—  The amount of material a river
can carry
—  Too much water (rain)
—  River over flows its banks
—  Why live on a floodplain?
—  Fertile soils
—  Great for farming
—  What happens to carrying
capacity if discharge
increases?
—  Carrying capacity increases
with an increase in discharge
Meandering Rivers
Meandering Rivers
—  Where they begin
—  Headwaters
—  Headward erosion
—  Increases the length of the
stream
—  Channels shape
—  V shape
Meandering Rivers
—  Conditions for Meandering River
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—
—
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Decrease in slope
Becomes wider
Sediment increases
Begins to bend
—  Finds slightly lower elevation
Meandering Rivers
—  Highest Velocity
—  Middle of the straight channel
—  Why?
—  Friction along edges and bends
—  Outside of the curve
—  Erosion
—  Inside curve
—  Deposition
3 3/5/12 Meandering Rivers
Meandering Rivers
—  Oxbow lake
—  When a winding curve cuts
off a meander
—  Stream flows relatively
straight
Meandering Rivers
Deltas vs. Alluvial Fans
—  Where sediments are deposited
—  Mouth of river (end of river)
—  Delta
—  Water
—  Silt an clay
—  Δ
—  Alluvial Fan
—  Dry land
—  Sand and gravel
—  Fan shaped
Deltas vs. Alluvial Fans
—  Delta
—  Δ
Lakes
—  A body of still water in a basin
surrounded by land
—  How organisms effect lakes
—  Plants add oxygen
—  Fish use oxygen
—  Bacteria feed on decaying
—  Alluvial Fan
organisms
—  Use oxygen
—  Fan shaped
4 3/5/12 Lakes
—  Dissolved Oxygen
—  Determines the quality
of a lake
—  Low in D.O.
—  Not enough oxygen for
fish
—  High in D.O.
—  Good for fish
Lakes
—  Eutrophication
—  A lake is high in nutrients
—  Effects
—  Algae growth
—  Plants die
—  Settle at bottom of lake
—  Bacteria feed off algae
—  Increase in bacteria
—  Use up oxygen
—  Decrease in Dissolved
Oxygen
—  Decrease in Lake quality
Lakes
—  Age of Lakes
Lakes
—  Aquatic Life Zones
—  Youngest
—  Oligotrophic
—  Middle aged
—  Mesotrophic
—  Oldest
—  Eutrophic
—  Increase in productivity
PROFUNDAL
—  Amount of solar energy
converted to plant
material through
photosynthesis
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