Monitoring Vegetation Phenology With Remote Sensing

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Monitoring Vegetation Phenology WithRemote
Sensing
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Outline

• Brief introduction to vegetation phenology and
  remote sensing
• Introduction to MODIS and several MODIS products
  that may be useful for studies of phenology
• Introduce my research and how I might use remote
  sensing and phenology

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Phenology

• The scientific study of periodic biological
  phenomena, such as flowering, breeding, and
  migration, in relation to climatic conditions

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Phenology and Remote Sensing

• Explore variation in phenology over large spatial
  scales.

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Phenology and Remote Sensing

• Queensland, Australia 2-15-2004
• New plant growth following drought ending
  rains.(MODIS false color image, swath width 2,330
  km)

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Phenology and Remote Sensing

• Explore variation in phenology over large spatial
  scales.
• Use interpecific variation in phenology to
  classify vegetation

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Using phenology to map vegetation
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Phenology and Remote Sensing

• Explore variation in phenology over large spatial
  scales.
• Use interpecific variation in phenology to
  classify vegetation
• Large database of global records
• AVHRR- June 1979-present
• MODIS 2000-present

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NDVI

• Normalized Difference Vegetation Index
• (NIR band-Red band)/(NIR bandRed band)
• Takes advantage of strong reflectance of
  vegetation in the NIR band
• Values range from -1 to 1. Pixels with no
  vegetation will usually have values of 0. Pixels
  with values of 1 have highest density of green
  leaves.

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Limitations of Remote Sensing

• R and NIR reflectance cannot penetrate cloud
  cover. Limits temporal resolution for time
  series.
• Poor spatial resolution (limits species specific
  information)
• High view angle bias.

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Why use MODIS?

• Good temporal resolution
• Global coverage every 1-2 days.
• Observations are corrected for atmospheric
  effects.
• Ancillary data concerning snow, ice and cloud
  effects provided
• Some correction for multi-view angles.
• You cant beat the price!!!

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Now for some MODIS specific products
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MODIS Products

• MODIS vegetation indexes
• Spatial Resolution 250m, 500m, 1km, .05 Degrees.
• Temporal Resolution 16 day composite, monthly
  composite
• NDVI
• Enhanced vegetation Index (EVI)

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MODIS Products

• EVI-optimizes sensitivity in high biomass areas,
  decouples canopy background signal, reduces
  atmospheric influences
• EVI G(?NIR-?Red)/ (?NIRC1 ?Red- C2?BlueL)
• ? atmospherically corrected surface reflectances
• L1 (Canopy background adjustment)
• C16, C27.5 (Corrects for aerosol influence in
  the red band)
• G2.5 (Gain factor)

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MODIS Products

• Nadir bidirectional reflectance distribution
  function adjusted reflectance (NBAR)
• Spatial resolution 1km, .05 degrees
• Temporal resolution 16 Day composites
• Effects of multi-view angles are removed
• Cloud cover is explicitly masked out

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MODIS Products

• Land surface skin temperature (LST)
• Spatial Resolution 1km, 5km, .05 degrees
• Temporal Resolution daily, 8 day, monthly.
• Accuracy is within 1C.

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Pteropus scapulatus
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P. scapulatus ecology

• Roost in mangroves, Eucalyptus forests and
  woodlands.
• Forages primarily on blossoms in Eucalyptus and
  Melaleuca forests within 30 km of roosts.
• Highly nomadic, can fly over 100km in a day.

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P. scapulatus ecology

• Little reds will roost in colonies gt 500,000
  individuals

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Disease Outbreaks

• Cairns 1999

Mackay 1994
Hendra Brisbane 1994
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Modeled distribution based on mean annual climate
variables
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Land Cover Change?
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Phenology

• Eucalyptus flower every 1-3 years.
• Flowers are patchily distributed in time and space

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(No Transcript)
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Animal response to vegetation?
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Animal response to vegetation?

• Band Min Max Mean
  Stdev
• 1 -0.023900 0.621000 0.385173 0.085194
• Band Min Max Mean
  Stdev
• 1 -0.012500 0.627100 0.374187
  0.083576

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Animal Response to Temperature?
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Animal Response to Temperature?

• Min Max Mean
  Stdev
• -10.059998 24.600006 21.476334 1.895412
• Min Max Mean
  Stdev
• -12.660004 22.660004 20.946791 1.971948

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Animal Response to Vegetation?
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Animal response to vegetation?

• Band Min Max Mean
  Stdev
• 1 -0.055800 0.492600 0.282170 0.074718
• Band Min Max Mean
  Stdev
• 1 -0.023100 0.514000 0.272219 0.077194

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Animal Response to Temperature?
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Animal Response to Temperature?

• Min Max Mean
  Stdev
• -144.320007 28.779999 25.451279 5.573332
• Min Max Mean
  Stdev
• -145.240005 26.919983 23.213643 5.548680

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Hervey Bay vs. GladstoneEVI

• Band Min Max Mean
  Stdev
• 1 -0.012500 0.627100 0.374187
  0.083576
• Band Min Max Mean
  Stdev
• 1 -0.023100 0.514000 0.272219 0.077194

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Hervey Bay vs. GladstoneTemperature

• Min Max Mean
  Stdev
• -12.660004 22.660004 20.946791 1.971948
• Min Max Mean
  Stdev
• -145.240005 26.919983 23.213643 5.548680