Watersheds and Wetlands

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Watersheds and Wetlands
CHAPTER 1
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• Lesson 1.1
• The Blue Planet
• Groundwater
• Surface Water
• Stream Characteristics
• Major Drainage Patterns
• Pennsylvanias Drainage Patterns

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PA Academic Standards for Environment Ecology

• Standard 4.1.10.B
• Explain the relationship among landforms,
  vegetation and the amount and speed of water.
• Lesson Objectives. Students will be able to
• Analyze a streams physical characteristics.
• Describe how topography influences streams.
• Explain the influence of mountains on
  precipitation.
• Explain how vegetation affects storm water
  runoff.
• Delineate the boundaries of a watershed.
• Describe factors that affect the quality of
  groundwater.
• Explain how the speed of water and vegetation
  cover relates to erosion.

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The Blue Planet

• Water is the most common substance on Earth.
• 97 of the Earths water is saltwater.
• Example oceans
• 3 of the Earths water is freshwater.
• Example lakes, rivers, streams, and glaciers

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• There are three main forms (states) in which
  water exists as it circulates through the water
  cycle.
• Solid
• Example ice
• Liquid
• Example water
• Gas
• Example water vapor

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• The three forms of water move water through the
  environment via the water cycle --- an unending
  circulation process powered by the sun.
• Major Processes
• Evaporation changing from a liquid to a gas
  (heating)
• Condensation changing from a gas to a liquid
  (cooling)
• Precipitation when water returns to the Earth
• Transpiration when plants release water vapor
  from
• their leaves
  (stomata)
• Percolation/Infiltration when surface water
  seeps into
• the
  ground

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Groundwater

• Some precipitation runs off the surface of the
  ground into near-by surface water sources.
  However, some water seeps into the ground and
  becomes groundwater.
• Definition Groundwater
• water from rain and melting snow that seeps into
  the ground and is stored beneath Earths surface

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Groundwater
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Where is the groundwater supply?

• About 22 of the Earths freshwater supply is
  groundwater.
• Groundwater can be accessed by private and public
  wells.
• How is groundwater used in PA?

• People and industry use more than 1 billion
  gallons of
• groundwater each day.
• Major source of drinking water for residents.
• Major source of water for mining and
  agricultural operations
• throughout the state.

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Overdrawing Groundwater

• Intro To increase supplies of high quality
• freshwater, groundwater is being used
• Groundwater is not an unlimited resource
• Balance should be
• Groundwater withdrawal recharge
• The truth
• Withdrawals exceed recharge!

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The Biggest Problem with overdrawing groundwater
Falling Water Tables The affects of this would
be

• Irrigation
• Uses up by far the most groundwater
• In the Midwest, Ogallala Aquifer
• Over the past 40 years, the water table has
  dropped 100 feet
• It continues to fall at a rate of 6 feet per year

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• 2. Diminishing Surface Water
• Springs and seeps dry up (lakes and ponds are
  affected)
• Wetlands dry up

• 3. Land Subsidence
• Water pressure underground acts as a support
• When that water is lost, the earth may settle or
  
• suddenly sink (sinkhole)
• Very typical in the southeast U.S.

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• 4. Saltwater Intrusion
• Coastal regions have springs that empty into the
  ocean
• As long as the water table is high, the pressure
  of the
• groundwater exiting the spring results in
  freshwater
• entering the ocean
• If the water table diminishes, then saltwater
  flows back
• into the freshwater

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Groundwater Quality

• Groundwater supplies much of the Earths drinking
  water supply.
• Therefore, the quality of the groundwater in many
  countries is closely monitored for contamination.
• Major causes of contamination
• Natural sources
• Human activities

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Video Clip Water Contamination
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Contamination Natural Sources

• As water flows through and around soils and
  rocks, it dissolves certain minerals, which
  contaminate the water.
• If the water is acidic, it can leach out metals
  from the ground.
• Example hard water (Ca Mg)
• Example overall reduced water quality (Fe,Zn,Cu
  and S)

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Contamination Human Activities

• Groundwater quality can also be adversely
  affected by human activities that occur above
  ground.
• Examples septic tanks, pesticides and
  fertilizers, storage tanks, chemical spills,
  landfills, and roadway salts.

How does my septic system well work?
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PAs Groundwater Quality

• Overall quality of groundwater in Pennsylvania is
  generally good.
• The decrease in the amount of nitrates in some
• Pennsylvania groundwater supplies could be a
  result of a combination of changes in
  agricultural practices and better installation
  and maintenance of septic systems.
• The increases in the amount of other
  contaminants in some parts of the state have been
  attributed to a rise in the amount of road salt
  applied to roadways as well as urban development.

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The 1 source of pollution along the Susquehanna
is agriculture.
What can farmers do?
Terracing
Stream Bank Fencing
Riparian Zone
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Proper Manure Management
Reduce Fertilizers Pesticides
No-till farming
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Surface Water

• Common freshwater sources
• Lakes
• Ponds
• Rivers
• Soils
• Air

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Stream Characteristics

• Velocity
• Sediment Load
• River Deposits

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Stream Characteristics

• (1) Velocity
• Definition The distance water flows during
  some
• period of time, such as
  meters per second
• or feet per second
• As a stream flows from its source to its
  mouth, the
• water flows in one of two ways.
• Laminar flow
• Water moves parallel to the stream channel
• Turbulent flow
• Water moves in tiny circular paths as it flows
  downstream

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• The velocity of a stream or river determines the
  type of flow observed in a system.
• Slow moving waters tend to have a laminar flow.
• Fast moving waters tend to have a turbulent
  flow.
• The velocity of the stream or river determines
  the kind and amount of sediment that the water
  can carry.

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• (2) Sediment Load
• As streams and rivers flow they carry sediment
  in three major ways.
• Dissolved load
• Sediment carried in solution
• Suspended load
• Silts and clays
• Bed load
• Sand, gravel, pebbles, and boulders (carried
  along the bottom)

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• (3) River Deposits
• Rivers deposit sediment as the velocity of the
  water decreases.
• Example bars, or river deposits, form when a
  river slows down as it travels around a bend in
  the channel.
• A flood plain is the part of a river valley that
  is covered during a flood.

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River deposits and agriculture

• Why are river deposits important to agriculture?
• Rivers deposit sediment when they overflow their
  banks into floodplains, or low lying portions of
  land next to rivers that fill with water as river
  levels rise.
• These areas are fertile areas for farming, as the
  soils are rich with sediments carried from
  upstream.

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Major Drainage Patterns

• Pennsylvania has more square miles of streams and
  rivers per square mile than most states.
• The drainage patterns of these rivers and their
  tributaries, or feeder steams, depends largely on
  topography, or the physical characteristics of
  the land.
• All drainage patterns are controlled by the types
  of rocks over which rivers and streams flow, as
  well as the presence or lack of folds and faults
  in the rocks.

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Topographic Maps
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Major Drainage Patterns

• Four major types of drainage patterns
• Dendritic Drainage Patterns
• Radial Drainage Patterns
• Rectangular Drainage Patterns
• Trellis Drainage Patterns

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Major Drainage Patterns
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Dendritic Drainage Patterns

• Most common type of drainage pattern.
• Form where bedrock is uniform and massive, such
  as in a plains region.
• Mainly a function of the slope of the land over
  which the stream or river flows.
• Resembles the shape of a mature tree.
• Common in western Pennsylvania because of a
  massive formation of sedimentary rock.

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Radial Drainage Patterns

• Form where streams flow from a high, central area
  such as a plateau or other uplifted feature.
• Resemble the spokes of a bicycle.

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Rectangular Drainage Patterns

• Form when bodies of rock are broken by a series
  of faults of other fractures.
• Resembles a series of lines, all of which turn at
  right angles.
• Common in South-central Pennsylvania because of
  fractures and faults in the Earths surface.

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Trellis Drainage Patterns

• Form when sections of softer, nonresistant rocks
  alternate with sections of harder, resistant
  rocks.
• Resembles rectangular drainage patterns but
  tributaries run parallel to one another.
• Common in southeastern Pennsylvania which has
  river systems which run parallel to each other
  yet perpendicular to the main stream or river.

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Theme Vocabulary

• Lesson 1.1
• bed load
• condensation
• evaporation
• groundwater
• mouth
• precipitation
• runoff
• source
• topography
• transpiration
• tributaries
• velocity