Mammoth Caves National Park, Kentucky

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Mammoth Caves National Park, Kentucky

• A collection of webcams of the Green River
  showing changes that occur on the landscape scale
  throughout a year (from July 2007 to June 2008)

Teachers version Includes narrative indicating
what changes are visible between webcam images.
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• Vegetation growing on the sandbars in the river
• Little distinction can be made between the
  different tree species during the summer.
• Trees that frame the webcam are deciduous but
  other species are presently indistinguishable.
• Sandbar outlined to show the change in size over
  next several slides, indicating a change in the
  discharge

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• Vegetation continues to grow on the sandbars
• Outlined sandbar is less exposed, indicating a
  rise in the water level (increase in discharge)
• River color is still the same as the last image
  river sediment has not changed

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• The sandbars in the river are at their greatest
  extent river water level (discharge) is low
• Trees growing on the right slope are in the
  beginning stages of changing color
• Some haze in sky (notice clearness on next slide)

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• Black line drawn on river marks the extent of the
  sandbar on the previous slide

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Leaves are starting to change
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Distinct leave color change
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• Vegetation on sandbar has changed to a brownish
  green color, another indication of the changing
  seasons

Noticeable differences in color
Water level as indicated by the bank
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• 4 days after the last image
• Heavy amounts of sediment in river - evidenced by
  rich brown color

Water level
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• Water level dropped bank edge is visible
  (arrow)
• Less sediment in river color returning to a
  greenish hue

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• Change of seasons makes it easier to see the
  complex series of slopes (drawn with black lines)
  within the valley
• Water level continues to drop bank edge
• Re-emergence of sand bar in river, indicating
  drop in water level
• Bare trees evident

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• Continued water level drop and emergence of
  secondary sand bar

Note different species of trees, based on leaf
color
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• Increase in water level, gravel bars immersed
• Deep red and orange leaves are most prominent now

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Near absence of deciduous leaves remaining on
trees
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Evergreen trees are only trees left with leaves
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• The river is noticeably greener indicating less
  sediment
• Gravel bars are also re-emerging

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• River flooding with a high sediment load caused
  the river to turn a sandy brown color
• The river is out of its bank with tree trunks in
  the water

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The extent of the flooding increased from the
last slide as more trees are now inundated with
flood waters
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A light covering of snow on the ground
illustrates the extent of the flood
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• 15 days after the last image
• Flood waters have decreased
• River is returning to a green hue

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A heavier snowfall this time again indicating
the extent of flooding
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The greatest flood event witnessed over a 12
month period with the flood waters at its
greatest extent out of its banks
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• Receding flood waters and a return of the natural
  color of the river
• A slight trace of spring green up can be found
  (arrow)

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• River is flooding again
• Spring green-up has begun
• Note the budding of the tree in the foreground
  over the next several images (arrow)

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Pink buds are fading, to be replaced with leaves
over the next several images
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• Gravel bars just beneath surface, general outline
  visible

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• Re-emergence of gravel bars

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• Submergence of gravel bars due to flooding
• Note high sediment load of river, evident from
  water color

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The camera angle was adjusted slightly between
May 3rd and May 6th (this webcam image). The
flood waters have receded slightly (bank is
visible (right arrow) Tree in foreground
continues to leaf-out (left arrow).
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Evidence of a recent flood is no longer visible
in this image the river is, once again, a
greenish hue, the bank is visible, and sand bars
in the middle of the river are slowly being
exposed
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The extent of sandbar exposure is similar to last
years webcam image, indicating it is probably
normal in the summer months