ASSESSING CHANGES IN MARSH CONDITION IN THE MID-ATLANTIC COAST USING LAND COVER DATA

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Assessing the Response of Coastal Marshes to Sea
Level Rise at a Coast-Wide Scale
Michael S. Kearney Department of
Geography and the Earth System Science
Interdisciplinary Center University of
Maryland College Park , MD 20742
TM Marsh Index Healthy, Mod Deterioration,
Severe Deterioration
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Canals in Holland regularly froze during Little
Ice Age (ca. 1400-1850)
Winter Landscape, Pieter Breugel the Younger
1601 Kunsthistorisches Museum, Vienna.
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Chesapeake Bay has had a slow rateof sea level
rise (0.56 mm/yr) overthe last thousand years
Kearney,M. 1996 J. Coastal Research 12 977-983
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Mean sea level has risen 30 cm(1 foot) over the
last century
PSMSL data
Baltimore tide gauge
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Declining Marsh at Blackwater NWR Barbados
Is. Oct. 2000
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Processes of Marsh Loss

• Local human activities ditching, diking, berms,
  tidal restrictions (roads), Nutria over-grazing,
  groundwater withdrawals, subsidence, etc.
• Sea Level Rise
• -slow vertical accretion (low tidal flushing)
• -plants dieback (especially during droughts)
• - formation of rotten spots then ponds
• -ponds coalescence to open embayments
  

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Blackwater WildLife Refuge c. 1902
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Physical changes in marsh condition accompany
marsh loss
Photo J. C. Stevenson
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Spatial Variation In Vertical Accretion Rates at
Monie Bay
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Sediment Elevation Table Measurements
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Typical Spectral Curves of Vegetation, Soil, and
Water
Vegetation
Soil
Water
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Atmospheric Correction Uncorrected
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Atmospheric Correction Corrected
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Band Slicing and Mixing
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Simulated Thematic Mapper data from Scirpus
americanus inundation experiment
Pixel Value
I
Inundation Depth (cm)
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Spectral Indices
1) Normalized Difference Water Index (NDWI)
(Band 3 - Band 5) / (Band 3 Band 5) 2)
Normalized Difference Vegetation Index (NDVI)
(Band 4 - Band 3) / (Band 4 Band 3) 3)
Normalized Difference Soil Index (NDSI) (Band 5
- Band 4) / (Band 5 Band 4).
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Endmember Spectra
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Data Processing Flow
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Validation Site For Marsh Condition Results
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Marsh Condition and Loss in Chesapeake Bay
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Change In Marsh Surface Condition 1984-1993 For
Delaware Bay
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Change Detection at Larger Scales
1984
1993
1984
1993
Changes in marsh condition between 1984-1993 at
Bombay Hook, Delaware based on the Landsat TM
MSCI model results. Green healthy to
slightly degraded marsh yellow moderately
degraded marsh red severely degraded marsh
blue water. The area covered by the images is
approximately 64 km2.
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Thematic class change 1988 - 2001
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Marsh condition class percentages (hectares) for
estuarine marshes in Chesapeake and Delaware Bays
based on 1993 Thematic Mapper imagery.
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Questions
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Leaf Area Index vs Canopy Height
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CLIMATE CHANGE VULNERABILITY AND ADAPTATION
The large scale features of climate change are
well understood, but the projections of change at
regional and smaller scales remain uncertain.

• OPEN WATER AREAS
• More extreme flows and
• stratification
• Habitat loss

• SHALLOW WATER AREAS
• Habitat SAV loss
• Carbon sources
• Total suspended solids

• COASTAL WETLANDS
• Loss of habitat and biodiversity
• Functional loss
• Loss coastal uplands

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SE 590 Spectroradiometer (252 detectors over a
range of 370-1100 nm) deployed 1.5 meters over
marsh with video camera to record water depths in
aluminum box
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Reflective Spectral Curves for 3 Brackish Marsh
Species
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Landsat TM Mixture Model

• Subpixel LOOK, Decomposes Each Pixel Into
  Vegetation, Soil, and Water Elements
• ?w1fw ?v1fv ?s1fs R1
• ?w2fw ?v2 fv ?s2fs R2
• ?w3fw ?v3fv ?s3fs R3
• The Indices are Independent, and Do Not Rely On
  Endmember Selection
• -A Critical In General PCA-Based Mixture Models