TM Marsh Index: Healthy, Mod Deterioration, Severe Deterioration

Assessing the Response of Assessing the Response of Coastal Marshes to Sea Level Coastal Marshes to Sea Level

Rise at a Coast-Wide ScaleRise at a Coast-Wide Scale

Michael S. KearneyMichael S. Kearney

Department of GeographyDepartment of Geography

andand

the Earth System Science Interdisciplinary Centerthe Earth System Science Interdisciplinary Center

University of MarylandUniversity of Maryland

College Park , MD 20742College Park , MD 20742

Winter Landscape, Pieter Breugel the Younger – 1601 Kunsthistorisches Museum, Vienna. Winter Landscape, Pieter Breugel the Younger – 1601 Kunsthistorisches Museum, Vienna.

Canals in Holland regularly froze Canals in Holland regularly froze during ‘Little Ice Age’ (ca. 1400-1850)during ‘Little Ice Age’ (ca. 1400-1850)

Chesapeake Bay has had a slow rateChesapeake Bay has had a slow rateof sea level rise (~0.56 mm/yr) overof sea level rise (~0.56 mm/yr) over

the last thousand yearsthe last thousand years

Kearney,M. 1996 J. Coastal Research 12: 977-983

Mean sea level has risen 30 cmMean sea level has risen 30 cm(1 foot) over the last century(1 foot) over the last century

Baltimore tide gauge Baltimore tide gauge

PSMSL data

Declining Marsh at Blackwater NWR & Barbados Is.; Oct. 2000Declining Marsh at Blackwater NWR & Barbados Is.; Oct. 2000

Processes of Marsh LossProcesses of Marsh Loss•Local human activities: ditching, diking, Local human activities: ditching, diking, berms, tidal restrictions (roads), Nutria over-berms, tidal restrictions (roads), Nutria over-grazing, groundwater withdrawals, subsidence, grazing, groundwater withdrawals, subsidence, & etc. & etc.

•Sea Level Rise:Sea Level Rise:

-slow vertical accretion (low tidal -slow vertical accretion (low tidal flushing)flushing)

-plants dieback (especially during -plants dieback (especially during droughts) droughts)

- formation of rotten spots & then ponds- formation of rotten spots & then ponds

-ponds coalescence to open embayments-ponds coalescence to open embayments

Blackwater WildLife Refuge Blackwater WildLife Refuge c. 1902c. 1902

Physical changes in marsh Physical changes in marsh condition accompany marsh condition accompany marsh

lossloss

Photo: J. C. StevensonPhoto: J. C. Stevenson

Spatial Variation In Vertical Accretion Spatial Variation In Vertical Accretion Rates at Monie BayRates at Monie Bay

Sediment Sediment Elevation Table Elevation Table MeasurementsMeasurements

Wavelength (nm)

Percent Reflectance

0

10

20

30

40

50

60398.9

430

464.4

501.8

540.2

578

615.9

653.8

690.9

727.6

771

816.4

846.7

887.8

932.7

975.7

1019.3

Typical Spectral Curves Typical Spectral Curves of Vegetation, Soil, and of Vegetation, Soil, and

WaterWaterVegetatioVegetationn

SoilSoil

WaterWater

Atmospheric Correction: Atmospheric Correction: UncorrectedUncorrected

Atmospheric Correction: Atmospheric Correction: CorrectedCorrected

Band Slicing and MixingBand Slicing and Mixing

Inundation Depth (cm)

Pixel Value

0

5

10

15

20

25

30

35

40

0 5

10

15

20

25

30

35

40

45

50

TMband1

TMband2

TMband3

TMband4

Simulated Thematic Mapper Simulated Thematic Mapper data from data from Scirpus americanus Scirpus americanus

inundation experimentinundation experimentP

ixel

Val

ue

Pix

el V

alu

e

IInundation Depth (cm)

Spectral IndicesSpectral Indices1) Normalized Difference Water Index 1) Normalized Difference Water Index (NDWI): (Band 3 - Band 5) /(NDWI): (Band 3 - Band 5) /

(Band 3 + Band 5);(Band 3 + Band 5);

2) Normalized Difference Vegetation 2) Normalized Difference Vegetation Index (NDVI): (Band 4 - Band 3) /Index (NDVI): (Band 4 - Band 3) /

(Band 4 + Band 3);(Band 4 + Band 3);

3) Normalized Difference Soil Index 3) Normalized Difference Soil Index (NDSI): (Band 5 - Band 4) /(NDSI): (Band 5 - Band 4) /

(Band 5 + Band 4).(Band 5 + Band 4).

0

50

100

150

200

250

1 NDSI 2 NDVI 3 NDWI

Res

cale

d R

efle

ctan

ce

Water Vegetation Soil

Endmember Spectra

Data Processing FlowImage IndicesImage Preprocessing

RawData

CalibratedData

ReflectanceConversion

CalibratedData

NDXILayeredIndices

NDSINDVINDWI

OptimizedEndmembers

Endmember SelectionAnd Evaluation

1m CIR Photos

Ref

lect

anc

e

Wavelength

Band X

Ban

d Y

Spectral Mixture AnalysisAnd Thematic Classification

NDXI Layered Indices SMA Fractions

RMSE Images Thematic Classification

MultitemporalSMA

Validation Site Validation Site For Marsh For Marsh Condition Condition ResultsResults

Marsh Condition Marsh Condition and Loss in and Loss in Chesapeake Chesapeake BayBay

Change In Marsh Change In Marsh Surface Condition 1984-Surface Condition 1984-1993 For Delaware Bay1993 For Delaware Bay

Change Detection Change Detection at Larger Scalesat Larger Scales

Changes in marsh condition between Changes in marsh condition between 1984-1993 at Bombay Hook, Delaware 1984-1993 at Bombay Hook, Delaware based on the Landsat TM MSCI model based on the Landsat TM MSCI model results. Green = healthy to slightly results. Green = healthy to slightly degraded marsh; yellow = moderately degraded marsh; yellow = moderately degraded marsh; red = severely degraded marsh; red = severely degraded marsh; blue = water. The area degraded marsh; blue = water. The area covered by the images is approximately covered by the images is approximately 64 km64 km22..

1984 199319841984 19931993

1988

20011999

1993

Water Upland Intact Moderate Severe

Thematic class change: 1988 - 2001

Area   Non-degraded

Slightly to moderately degraded

Severely to completely degraded

Chesapeake Bay

       

  Upper and middle Bay*

31 (25,201)

50 (40,647)

19 (15,446)

  Lower Bay

28 (9,404)

52 (17,464)

20 (6,717)

Delaware Bay

North Shore (New Jersey)

38 (27,095)

43 (30,660)

19 (13,547)

  South Shore (Delaware)

55 (19,974)

35 (12,711)

10 (3,632)

Marsh condition class percentages (hectares) Marsh condition class percentages (hectares) for estuarine marshes in Chesapeake and for estuarine marshes in Chesapeake and Delaware Bays based on 1993 Thematic Delaware Bays based on 1993 Thematic Mapper imageryMapper imagery.

QuestionsQuestions

Leaf Area Index Leaf Area Index vs Canopy vs Canopy HeightHeight

The large scale features of climate change are well The large scale features of climate change are well understood, but the projections of change at understood, but the projections of change at

regional and smaller scales remain uncertain.regional and smaller scales remain uncertain.

CLIMATE CHANGECLIMATE CHANGEVULNERABILITY AND ADAPTATIONVULNERABILITY AND ADAPTATION

SHALLOW WATER AREASSHALLOW WATER AREASHabitat & SAV lossCarbon sourcesTotal suspended solids

OPEN WATER AREASOPEN WATER AREASMore extreme flows and stratificationHabitat loss

COASTAL WETLANDSCOASTAL WETLANDSLoss of habitat and biodiversityFunctional lossLoss coastal uplands

SE 590 Spectroradiometer (252 detectors SE 590 Spectroradiometer (252 detectors over a range of 370-1100 nm) deployed over a range of 370-1100 nm) deployed

1.5 meters over marsh with video camera 1.5 meters over marsh with video camera to record water depths in aluminum boxto record water depths in aluminum box

Reflective Spectral Curves for 3 Brackish Marsh Reflective Spectral Curves for 3 Brackish Marsh Species Species

Landsat TM Mixture ModelLandsat TM Mixture Model

• Subpixel LOOK, Decomposes Each Pixel Subpixel LOOK, Decomposes Each Pixel Into Vegetation, Soil, and Water Into Vegetation, Soil, and Water ElementsElements

w1w1ffww + + v1v1ffvv + + s1s1ffss = R = R11

w2w2ffww + + v2v2 f fvv + + s2s2ffss = R = R22

w3w3ffww + + v3v3ffvv + + s3s3ffss = R = R33

• The Indices are Independent, and Do The Indices are Independent, and Do Not Rely On Endmember SelectionNot Rely On Endmember Selection-A Critical-A Critical In General PCA-Based In General PCA-Based

Mixture ModelsMixture Models