@PhDThesis{Marani:2007:EsEmMe,
author = "Marani, Luciano",
title = "Estudo da emiss{\~a}o de metano no Pantanal Sul Matogrossense",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2007",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2007-02-26",
keywords = "metano, {\'a}rea alagada, efeito estufa, varia{\c{c}}{\~a}o
sazonal, troposfera, methane, wetland, greenhouse effect, seasonal
variation, troposphere.",
abstract = "Apresentam-se os resultados de uma avalia{\c{c}}{\~a}o da
contribui{\c{c}}{\~a}o das {\'a}reas alagadas tropicais no
balan{\c{c}}o atmosf{\'e}rico de metano. Neste estudo, foram
realizadas oito campanhas na regi{\~a}o Sul-Matogrossense do
Pantanal durante os anos de 2004 e 2005, com coletas de amostras
em sete diferentes locais escolhidos pr{\'o}ximos ao Rio Miranda.
Utilizou-se a t{\'e}cnica de c{\'u}pula est{\'a}tica em
conjunto com a coleta de seringas de poliuretano. Na an{\'a}lise
dos fluxos, os locais de coleta foram divididos em lagoas e
plan{\'{\i}}cies alagadas e algumas vari{\'a}veis ambientais
que podem afetar a emiss{\~a}o de metano como a profundidade,
temperatura, pH e oxig{\^e}nio dissolvido tamb{\'e}m foram
medidas. A m{\'e}dia geral dos 560 fluxos v{\'a}lidos obtidos
nas campanhas entre mar{\c{c}}o de 2004 e dezembro de 2005 foi de
116.8 ± 257.8 mgCH4m-2d-1, com mediana de 11,1 mgCH4m-2d-1,
pr{\'o}ximo ao observado em outras regi{\~o}es alagadas
tropicais. Em cerca de 40% das medidas de fluxo ocorreram aumentos
n{\~a}o lineares na concentra{\c{c}}{\~a}o dentro das
c{\'u}pulas, os quais foram relacionados {\`a}
libera{\c{c}}{\~a}o de metano atrav{\'e}s de bolhas. O fluxo
ebulitivo representou cerca de 90% da libera{\c{c}}{\~a}o total
de metano para a atmosfera, e apresentou valores entre 1,1 e
2187,0 mgCH4m-2d-1 com uma m{\'e}dia de 279,5 ± 289,5 mgCH4m-2d-1
e mediana de 127,5 mgCH4m-2d-1. O fluxo difusivo variou entre 1,0
e 145,5 mgCH4m-2d-1 com uma m{\'e}dia de 13,1 ± 20,7 mgCH4m-2d-1
e mediana de 5,0 mgCH4m-2d-1. Os fluxos de lagoas foram menores
que os observados nas plan{\'{\i}}cies alagadas, onde o
alagamento {\'e} mais dependente do ciclo sazonal. O fluxo
difusivo mostrou uma pequena varia{\c{c}}{\~a}o sazonal, com
valores m{\'e}dios menores durante a esta{\c{c}}{\~a}o de seca.
Embora n{\~a}o tenham apresentado uma correla{\c{c}}{\~a}o
expl{\'{\i}}cita com os fluxos, a profundidade, a temperatura, a
quantidade de oxig{\^e}nio dissolvido e a presen{\c{c}}a de
vegeta{\c{c}}{\~a}o mostraram ter alguma influ{\^e}ncia nos
fluxos de metano. A partir da estimativa de {\'a}rea alagada
obtida de um modelo baseado em observa{\c{c}}{\~o}es de
sensoriamento remoto e da extrapola{\c{c}}{\~a}o de nossas
medidas para todo o Pantanal, foram feitas estimativas de
emiss{\~a}o para a regi{\~a}o. Considerando-se o fluxo
m{\'e}dio e {\'a}rea m{\'e}dia no per{\'{\i}}odo, a
emiss{\~a}o anual do Pantanal foi de 1,37 TgCH4/ano. Ao se
considerar as diferen{\c{c}}as observadas entre os habitats e a
influ{\^e}ncia da vegeta{\c{c}}{\~a}o nos fluxos, tem-se uma
emiss{\~a}o de 2.20 TgCH4/ano. Estas estimativas ainda conservam
grande incerteza, resultante da extrapola{\c{c}}{\~a}o das
medidas realizadas em uma regi{\~a}o para todo o Pantanal, mas
indicam que o Pantanal pode ser considerado uma das mais
importantes fontes natural de metano para a atmosfera na
Am{\'e}rica do Sul. ABSTRACT: The results of an evaluation of the
tropical wetland regions contribution to the methane burden are
presented. In this study, a total of eight campaigns were
performed during the years of 2004 and 2005 inside the Pantanal
region of Matogrosso do Sul State in seven sites, near the Miranda
River. Static chamber technique with polyurethane syringe sampling
was used. In the fluxes analyses, the sites were divided in lakes
and floodplains, and some environmental variables that can affect
methane emissions, as water depth, pH, dissolved oxygen and water
temperature were also measured. The overall average of the 560
individual methane valid fluxes measured from March, 2004 to
December, 2005 was 116.8 ± 257.8 mgCH4m-2d-1 and median of 11.1
mgCH4m-2d-1, near that observed in others tropical flooded
regions. In about 40% of flux measurements occurred non-linear
increases in the chamber concentrations that were assumed to be
linked to methane loses through bubbles. The bubble flux
represented about 90% of the total methane loses in the
measurements and ranged from 1.1 to 2187.0 mgCH4m-2d-1, with an
average of 279.5 ± 289.5 mgCH4m-2d-1 and median of 127.5
mgCH4m-2d-1. The diffusive fluxes ranged from 1.0 to 145.5
mgCH4m-2d-1, with an average of 13.1 ± 20.7 mgCH4m-2d-1 and median
of 5.0 mgCH4m-2d-1. The fluxes from lakes are smaller than that
observed in the floodplains, where the flooding was controlled by
the seasonal cycle. The diffusive flux showed a slight seasonal
variation, with small average fluxes during the dry season. A
direct correlation between fluxes and environmental factor (water
depth, water temperature, dissolved oxygen and presence of aquatic
vegetation) was not found, however, these factors showed to have
some influence on the methane fluxes. Estimates of methane
emission from the Pantanal were performed based on estimates of
flooded area obtained of a remote sensing model and the
extrapolation of our fluxes measurements to the whole region. When
considering just the average flux and the average flooded area in
the measurement period, the annual methane emission was of 1.37
TgCH4/year. When the observed difference between habits and the
influence of vegetation was considered, the annual emission was of
2.20 TgCH4/year. These estimates conserve a large uncertain
resulting of the extrapolation for the whole Pantanal of the
measurements made in one region only, but they indicate that the
Pantanal is one of the most important natural sources of
atmospheric methane in South America.",
committee = "Gonzalez Alarcon, Al{\'{\i}}cia Luisa Cl{\'u}a de (presidente)
and Alval{\'a}, Pl{\'{\i}}nio Carlos (orientador) and Batista,
Inez Staciarini and Novo, Evlyn Marcia Le{\~a}o de Moraes and
Andrade, Maria de Fatima and Lima, Magda Aparecida de",
copyholder = "SID/SCD",
englishtitle = "Study of methane emission on Pantanal of Matogrosso do Sul",
language = "pt",
pages = "108",
ibi = "6qtX3pFwXQZGivnK2Y/PQRoc",
url = "http://urlib.net/ibi/6qtX3pFwXQZGivnK2Y/PQRoc",
targetfile = "publicacao.pdf",
urlaccessdate = "11 maio 2024"
}