Regionalization of Methane Emission

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Regionalization of Methane Emission   from the
Amazon Basin   with Microwave Remote Sensing
John M. Melack University of California,
Santa Barbara Laura L. Hess, Mary Gastil,
Bruce R. Forsberg, Stephen K. Hamilton, Ivan
B.T. Lima, Evlyn M.L.M. Novo
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Evaluate emission of methane from Amazon
wetlands   Remotely-sensed estimates of
seasonally of inundation and wetland
vegetation Measurements of methane emission from
wetland habitats (open water, flooded forests and
floating macrophytes)
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Remote sensing of temporal variation in extent of
inundation and aquatic vegetation
Monthly inundated areas Mixture model of 37 GHz
polarization difference observed by Scanning
Multichannel Microwave Radiometer (1979-1987)
Inundation and aquatic vegetation at high (1996)
and low (1995) river levels Segmentation and
classification of L-band synthetic aperture radar
data obtained by Japanese Earth Resources
Satellite
Validation of inundation and aquatic vegetation
Examination of airborne digital videography
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R
N
A
B
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SMMR-based inundation area 7-year time series
for central Amazon study reach
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Cabaliana Floodplain
High Water
Low Water
Water Bare or herbaceous, non-flooded Herbaceous,
flooded Shrub, non-flooded
Shrub, flooded Woodland, flooded Forest,
non-flooded Forest, flooded
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Digital videography for validation
Hess et al. 2002. Int. J. Remote Sens. 23
1527-1556
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Areal extent of aquatic habitats on
Solimoes-Amazon floodplain
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Methane emission measurements
Selected habitat-specific measurements (aquatic
macrophytes, flooded forest and open water) from
Devol et al. (1990, JGR 95 16417-16426)
composited from 8 lake seasonal survey and
regional sampling using different emission rates
from aquatic macrophytes for high and low water
levels. River channel emission from Richey et
al. (1988, LO 33 551-561)
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CH4?habitat K (Csurface Catm equil)
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Uncertainty Analysis
Uncertainties in the regional emission rates were
determined by Monte Carlo error analyses that
combined error estimates for the measurements of
emission and for calculations of inundation and
habitat areas.
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Solimoes Amazon River Floodplain
Methane Emission, Tg C y-1 Aquatic
macrophytes 0.63 0.1   Flooded forest 0.61
0.2   Open water 0.087 0.02   River
channel 0.008 0.001   Total 1.3 0.3
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Methane emission from Solimoes-Amazon floodplain
Mean Area uncertainty
min mean max
Minimum, mean and maximum inundation (Sippel et
al. 1998) with uncertainty derived from monte
carlo error analysis. Methane emission from Devol
et al. (1990)
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Central Amazon Basin (1.77 million km2)
Methane Emission CO2 Evasion Tg C y-1
Tg C y-1 6.8 1.3
210 60
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Amazon Basin below 500m wetlands 17, uplands
83
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Lowland Amazon Basin (lt500 m asl) (5.19 million
km2)
Methane Emission 22 Tg C y-1   Greenhouse
gas potential 0.5 Pg C y-1 as CO2
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Tropical South American Savannas
Mean Flooded Methane Emission
Area, km2 Tg C y-1 Mojos 29,500
2.1   Roraima 3,500
0.3   Bananal 13,100
0.9   Orinoco 34,700
2.5   Pantanal 34,900 2.5
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Research Needs
Process-based models Ecological studies and
methane emission measurements Seasonally
flooded savannas Floodplains in eastern
Peru Interfluvial wetlands in upper Negro
basin Freshwater wetlands in Amazon
delta Riparian zones of streams
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References Melack et al. 2004. Regionalization
of methane emission in the Amazon Basin with
microwave remote sensing. Global Change Biology
10 in press Hess et al. 2003. Dual season
mapping of wetland inundation and vegetation for
the central Amazon basin Remote Sensing of
Environment 87 404-428 Hess et al. 2002.
Geocoded digital videography for Validation of
land cover mapping in the Amazon basin. Internat.
J. Remote Sensing 23 1527-1555 Sippel et al.
1998. Passive microwave observations of
Inundation area and the area/stage relation in
the Amazon River floodplain. Internat. J. Remote
Sensing 19 3055-3074