@PhDThesis{Curtarelli:2016:VaEsTe,
author = "Curtarelli, Marcelo Pedroso",
title = "Variabilidade espacial e temporal do fluxo difusivo de CO2 no
reservat{\'o}rio hidrel{\'e}trico de Tucuru{\'{\i}},
Amaz{\^o}nia, Brasil",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2016",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2016-03-10",
keywords = "emiss{\~a}o de di{\'o}xido carbono, reservat{\'o}rios
hidrel{\'e}tricos, Amaz{\^o}nia, aplica{\c{c}}{\~o}es
multissensores, modelos tridimensionais, carbon dioxide emission,
hydroelectric reservoirs, Amazon region, multisensor applications,
three-dimensional models.",
abstract = "A hip{\'o}tese que motivou esta pesquisa foi a de que a atual
estimativa de emiss{\~a}o total de carbono por reservat{\'o}rios
hidrel{\'e}tricos Amaz{\^o}nicos {\'e} imprecisa, uma vez que a
variabilidade espacial e temporal do fluxo difusivo de
CO\$_{2}\$ n{\~a}o {\'e} considerada de maneira adequada.
Desta forma, o presente trabalho teve o objetivo de estudar a
din{\^a}mica da variabilidade espacial e temporal do fluxo
difusivo de CO\$_{2}\$ no reservat{\'o}rio de Tucuru{\'{\i}},
Par{\'a}, ao longo das esta{\c{c}}{\~o}es de ver{\~a}o e
inverno, e em condi{\c{c}}{\~o}es de clima atual e futuro. Para
tanto foi utilizada uma abordagem inovadora que buscou integrar
dados coletados \emph{in situ}, dados obtidos por sensoriamento
remoto e o uso de modelagem num{\'e}rica tridimensional para
simula{\c{c}}{\~a}o do fluxo difusivo de CO\$_{2}\$ . Foram
realizados experimentos em condi{\c{c}}{\~o}es de clima presente
(ano 2013) e clima futuro (ano 2100), considerando dois
cen{\'a}rios distintos do ponto de vista clim{\'a}tico e de
mudan{\c{c}}as no uso e cobertura do solo na bacia de
contribui{\c{c}}{\~a}o do reservat{\'o}rio. Os resultados
obtidos a partir dos experimentos realizados em
condi{\c{c}}{\~o}es de clima presente mostraram que o fluxo
difusivo de CO\$_{2}\$ apresenta alta variabilidade espacial e
temporal em Tucuru{\'{\i}}. Temporalmente, o fluxo difusivo de
CO\$_{2}\$ variou, em m{\'e}dia, entre -86 e -24 mg C
m\$^{-2}\$ hora\$^{-1}\$ ao longo do dia no ver{\~a}o e entre
-105 e -30 mg C m\$^{-2}\$ hora-1 ao longo do dia no inverno. Em
ambos os per{\'{\i}}odos analisados as maiores taxas de
emiss{\~a}o foram observadas no per{\'{\i}}odo noturno e
in{\'{\i}}cio da manh{\~a} e as menores no per{\'{\i}}odo da
tarde. O valor di{\'a}rio m{\'e}dio do fluxo difusivo de
CO\$_{2}\$ obtido para o per{\'{\i}}odo de ver{\~a}o foi de
-1.338 \$\pm\$ 1.335 mg C m\$^{-2}\$ dia\$^{-1}\$ e de
-1.395 \$\pm\$ 925 mg C m\$^{-2}\$ dia\$^{-1}\$ para o
per{\'{\i}}odo de inverno. Do ponto de vista espacial, o fluxo
difusivo de CO\$_{2}\$ apresentou um padr{\~a}o
heterog{\^e}neo durante todo o ver{\~a}o, variando, em
m{\'e}dia, entre -6.950 (zona de transi{\c{c}}{\~a}o) e 32 mg C
m\$^{-2}\$ dia\$^{-1}\$ (absor{\c{c}}{\~a}o no interior dos
igarap{\'e}s). Por outro lado, durante o inverno o fluxo difusivo
de CO\$_{2}\$ apresentou um padr{\~a}o homog{\^e}neo, com
grande parte da superf{\'{\i}}cie do reservat{\'o}rio
apresentando valores pr{\'o}ximos {\`a} m{\'e}dia espacial. Os
principais fatores ambientais influenciando a evas{\~a}o de
CO\$_{2}\$ em Tucuru{\'{\i}} foram a velocidade de troca
gasosa, temperatura da coluna d'{\'a}gua, press{\~a}o parcial de
CO\$_{2}\$ na {\'a}gua e componentes do balan{\c{c}}o
energ{\'e}tico na camada de mistura. Desta forma a
atua{\c{c}}{\~a}o de sistemas convectivos de mesoescala sobre o
reservat{\'o}rio de Tucuru{\'{\i}} apresentou o potencial de
aumentar a evas{\~a}o de CO\$_{2}\$ em cerca de 28\% nos dias
em que ocorrem, uma vez que estes sistemas alteram as
condi{\c{c}}{\~o}es ambientais na regi{\~a}o. Em
condi{\c{c}}{\~o}es de clima futuro, os experimentos realizados
apontam que o fluxo difusivo poder{\'a} ser impactado de
diferentes formas, sendo a eutrofiza{\c{c}}{\~a}o do
reservat{\'o}rio, associada {\`a}s mudan{\c{c}}as no uso e
cobertura do solo na bacia de contribui{\c{c}}{\~a}o, um dos
principais fatores que ir{\'a} influenciar as emiss{\~o}es de
CO\$_{2}\$ no futuro. Os resultados alcan{\c{c}}ados na
pesquisa permitiram aceitar a hip{\'o}tese inicial, sendo
demonstrado que a varia{\c{c}}{\~a}o espacial e temporal do
fluxo difusivo de CO\$_{2}\$ s{\~a}o aspectos importantes a
serem considerados durante as estimativas de emiss{\~a}o de C em
reservat{\'o}rio hidrel{\'e}tricos Amaz{\^o}nicos. Extrapolando
os resultados obtidos nesta pesquisa para todo o bioma
Amaz{\^o}nico, especula-se que a emiss{\~a}o total de carbono
por reservat{\'o}rios de usinas hidrel{\'e}tricas possa ser
at{\'e} 22\% menor do que a estimativa mais atual reportada na
literatura (9 Tg C ano\$^{-1}\$). Esta diferen{\c{c}}a
significativa n{\~a}o deve ser negligenciada, uma vez que a
emiss{\~a}o de carbono {\'e} um fator chave quando se comparam
os impactos ambientais de diferentes fontes de gera{\c{c}}{\~a}o
de energia el{\'e}trica podendo influenciar a tomada de
decis{\~a}o para a escolha da fonte mais adequada do ponto de
vista ambiental e no local de constru{\c{c}}{\~a}o de novos
empreendimentos hidrel{\'e}tricos. ABSTRACT: The hypothesis that
motivated this research was that the current estimate of the total
carbon emissions by Amazonian hydroelectric reservoirs is
inaccurate, since the spatial and temporal variability of the
diffusive CO\$_{2}\$ flux is not considered properly. Thus, this
study aimed to study the spatial and temporal variability of the
diffusive CO\$_{2}\$ flux in the Tucuru{\'{\i}} reservoir,
Par{\'a}, along the summer and winter seasons, and for current
and future climate conditions. For this purpose we used an
innovative approach which integrates data collected \emph{in
situ}, data obtained by remote sensing and the use of
three-dimensional numerical modeling to simulate the CO\$_{2}\$
diffusive flux. Experiments were carried out for present climate
conditions (year 2013) and future climate conditions (2100),
considering two different scenarios of climate and land use and
land cover changes in the reservoir basin. The results obtained
for the experiments conducted under present climate conditions
showed that the diffusive CO\$_{2}\$ flux has a high spatial and
temporal variability in Tucuru{\'{\i}}. Temporally, the
diffusive flux of CO\$_{2}\$ ranged, on average, between -86 and
-24 mg C m\$^{-2}\$ hour\$^{-1}\$ throughout the day in the
summer season and between -105 and -30 mg C m\$^{-2}\$
hour\$^{-1}\$ during the winter season. In seasons analyzed the
highest emission rate was observed during the night and early
morning, and the lowest rate during the afternoon. The mean daily
value of the CO\$_{2}\$ diffusive flux obtained for the summer
period was -1338 \$\pm\$ 1.335 mg C m\$^{-2}\$ day\$^{-1}\$
and -1395 \$\pm\$ 925 mg C m\$^{-2}\$ day\$^{-1}\$ for the
winter period. From the spatial point of view, the diffusive flux
of CO\$_{2}\$ showed a heterogeneous pattern during the summer,
ranging between -6.950 (transition zone) and 32 mg C m\$^{-2}\$
day\$^{-1}\$ (absorption within the littoral zone). Moreover,
during the winter season the diffusive flux of CO\$_{2}\$ showed
a homogeneous pattern. The main environmental factors influencing
the evasion of CO\$_{2}\$ in Tucuru{\'{\i}} reservoir were the
gas exchange piston velocity, temperature of the water column,
partial pressure of CO\$_{2}\$ in the water and the components
of energy balance in the mixed layer. Thus the occurrence of
mesoscale convective systems over Tucuru{\'{\i}} reservoir had
the potential to increase the evasion of CO\$_{2}\$ by about
28\% on days in which they occurs, since these systems change the
environmental conditions in the reservoir region. For the
experiments under future climate conditions, the results showed
that the diffusive CO\$_{2}\$ flux may be affected in different
ways and the eutrophication of the reservoir, associated with the
changes in land use and land cover in the reservoir basin, is one
of the main factors that will influence the emissions of
CO\$_{2}\$ in the future. The outcomes of this research allowed
to accept the initial hypothesis, and demonstrated that the
spatial and temporal variability of CO\$_{2}\$ diffusive flux
are important aspects to be considered for the total carbon
emission estimates in hydroelectric reservoir located at Amazon
biome. Extrapolating the results obtained in this study for the
entire Amazon biome, it is speculated that the total carbon
emissions by hydroelectric reservoirs can be up to 22\% less than
the latest estimate reported in the literature (9 Tg C
yr\$^{-1}\$). This significant difference should not be
neglected, since the carbon footprint is a key factor when
comparing the environmental impacts of different sources of
electricity generation and can influence the decision-making
process for choosing the most appropriate source and the
construction site of new hydroelectric projects.",
committee = "Stech, Jos{\'e} Luiz (presidente) and Lorenzzetti, Jo{\~a}o
Antonio (orientador) and Kampel, Milton and Fernandez, Julio Pablo
Reyes and Damazio, Jorge Machado and Tundisi, Jos{\'e} Galizia",
copyholder = "SID/SCD",
englishtitle = "Spatio-temporal variability of diffusive CO2 flux in the
Tucuru{\'{\i}} hydroelectric reservoir, Amaz{\^o}nia, Brazil",
language = "pt",
pages = "183",
ibi = "8JMKD3MGP3W34P/3L6FL6E",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3L6FL6E",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}