Floodplain%20Dynamics%20and

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Floodplain Dynamics and Carbon Fluxes John M.
Melack University of California, Santa Barbara
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Key aspects of floodplain systems   Amplitude
, frequency, predictability of
flooding   Vegetative cover and extent of open
water
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Cabaliana floodplain Flooded forest, woodland,
and shrub vegetation
Upper and lower left high water Lower right low
water
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Cabaliana floodplain Aquatic macrophyte
(floating meadow) vegetation
Upper and lower left high water Lower center and
right low water
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Functional Characterization of Floodplains B
asinwide analyses using a classification system
suitable for multiple applications
Biogeochemical and hydrologic modeling
Resource management and development planning
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Analysis Approach Characteristics
detectable using satellite remote sensing satisfy
the key requirements Vegetation
structure Inundation periodicity
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Inundation and aquatic vegetation An Amazon
example
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Central Amazon Wetlands Mapping from JERS-1
Mosaics (100 m resolution)
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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
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Evaluate evasion of CO2 from rivers and
floodplains in central Amazon basin
  Remotely-sensed and geomorphically-derived
estimates of inundation Measurements of dissolved
CO2 Calculation of CO2 evasion to the
atmosphere Richey, J.E., J.M. Melack, A.K.
Aufdenkampe, V.M. Ballester, and L. Hess. 2002.
Nature 416 617-620.
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Inundation in Amazon Rivers
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5
2
0
1
5
Flooded Area (x 104 km2)
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0
5
0
J
F
M
A
M
J
J
A
S
O
N
D
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What are fluxes of carbon associated with rivers
and wetlands in the Amazon?   Basin-wide, evasion
of CO2 from rivers and wetlands to the atmosphere
is about 0.5 Gt C y-1.   Amazon River export to
the ocean is 0.036 Gt C y-1 of organic carbon and
0.035 Gt C y-1 of dissolved inorganic carbon.
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Evaluate evasion 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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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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Carbon budget for Amazon basin, summed over
terrestrial and aquatic environments, appears
closer to being in balance than inferred from
upland data alone.
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Exchanges In Floodplain Systems
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Lake Calado Inputs N() P() Direct
rainfall 8 6 Surface runoff 42 11 Groundwater 8
19 Adjacent lakes 8 13 Amazon River 24 51
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How does water flow through these environments?
100 Inundated