@MastersThesis{Lira:2019:CaEsSe,
author = "Lira, Tamires Alybia Gomes de",
title = "Caracteriza{\c{c}}{\~a}o espa{\c{c}}o-temporal das secas sobre
o Brasil nas {\'u}ltimas d{\'e}cadas (1981-2016)",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2019",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2019-08-14",
keywords = "secas, {\'{\i}}ndice de sa{\'u}de da vegeta{\c{c}}{\~a}o
(ISV), diagn{\'o}stico clim{\'a}tico, drought, vegetation health
index (VHI), climatic diagnostic.",
abstract = "Fen{\^o}menos de seca frequentemente s{\~a}o alvos de estudos
meteorol{\'o}gicos devido {\`a} severidade de seus impactos
tanto ao meio ambiente quanto {\`a} sociedade em geral.
Ultimamente, alguns desses estudos, realizados para as
regi{\~o}es Nordeste, Sudeste e regi{\~a}o Norte Brasil, com
objetivo de investigar as secas atrav{\'e}s de perspectivas tais
como a frequ{\^e}ncia de ocorr{\^e}ncia, dura{\c{c}}{\~a}o e
intensidade, aparentemente demonstram que as {\'a}reas atingidas
pelas secas t{\^e}m aumentado a cada evento. Sendo assim, o
presente trabalho tem como objetivo caracterizar as secas em seu
aspecto espacial e temporal para todo territ{\'o}rio brasileiro
nas {\'u}ltimas d{\'e}cadas (1981 - 2016). Para isso, foram
utilizados dados de precipita{\c{c}}{\~a}o,
precipita{\c{c}}{\~a}o-evapora{\c{c}}{\~a}o e o
{\'{\I}}ndice de Sa{\'u}de da Vegeta{\c{c}}{\~a}o (ISV)
estimado a partir de dados de sat{\'e}lite. Al{\'e}m de
diagnosticar esse aspecto do fen{\^o}meno, tamb{\'e}m
prop{\~o}e-se a investigar a expans{\~a}o espacial das secas ao
longos dos anos sob o ponto de vista de poss{\'{\i}}veis
mudan{\c{c}}as nos padr{\~o}es de circula{\c{c}}{\~a}o
atmosf{\'e}rica, varia{\c{c}}{\~a}o na distribui{\c{c}}{\~a}o
de precipita{\c{c}}{\~a}o ou ainda altera{\c{c}}{\~o}es no
comportamento da TSM (Temperatura da Superf{\'{\i}}cie do Mar).
Como material de estudos das conex{\~o}es dos eventos de secas e
as demais vari{\'a}veis meteorol{\'o}gicas foram utilizados
dados de circula{\c{c}}{\~a}o atmosf{\'e}rica do CFSR (Climate
Forecast System Reanalysis), de precipita{\c{c}}{\~a}o do MSWEP
(Multi-Source Weighted-Ensemble Precipitation),
precipita{\c{c}}{\~a}o-evapotranspira{\c{c}}{\~a}o e
velocidade vertical (omega) da rean{\'a}lise ERA-Interin e de TSM
da s{\'e}rie de Reynolds. Os resultados mostraram que os
{\'{\i}}ndices de vegeta{\c{c}}{\~a}o e de umidade indicam
aumento das {\'a}reas de seca no Brasil para as {\'u}ltimas
d{\'e}cadas, principalmente para o per{\'{\i}}odo decenal de
2008 - 2016. O trimestre DJF mostrou tend{\^e}ncias lineares mais
marcadas para este mesmo per{\'{\i}}odo, indicando um aumento
das {\'a}reas atingidas por condi{\c{c}}{\~o}es de seca em todo
o pa{\'{\i}}s durante o ver{\~a}o. As an{\'a}lises das
anomalias de TSM e circula{\c{c}}{\~a}o indicaram
condi{\c{c}}{\~o}es de La Niņa ou El Niņo atuando em sete dos
noves anos da s{\'e}rie decenal. As an{\'a}lises das
circula{\c{c}}{\~o}es locais (para a Am{\'e}rica do Sul) e dos
movimentos verticais indicaram que al{\'e}m das anomalias de
circula{\c{c}}{\~a}o provocada por eventos ENOS na
circula{\c{c}}{\~a}o geral da atmosfera (ramo descendente da
c{\'e}lula de Walker no Brasil) a atua{\c{c}}{\~a}o de
anomalias de circula{\c{c}}{\~a}o anticicl{\^o}nica,
principalmente nos {\'u}ltimos anos da d{\'e}cada,
contribu{\'{\i}}ram para o aumento das {\'a}reas de seca no
pa{\'{\i}}s. ABSTRACT: Drought events have caused severe impacts
to the environment and society being therefore subject of several
studies. Recently, some researches were performed aiming to
investigate droughts throughout their frequency of occurrence,
duration and intensity for the Northeast, Southeast and the
Northern regions of Brazil. Results have shown that affected areas
increased each year. However, how large was the increase over the
whole country has not been explored. Thus, this research aims to
characterize droughts events in their spatial and temporal aspects
over all Brazilian territory during the last decades (1981 -
2016). In addition, possible changes in the atmospheric
circulation patterns, modifications in the distribution of the
precipitation and changes in the Sea Surface Temperature (SST)
patterns were also investigated. For such purposes various
datasets were used, including precipitation data from the
Multi-Source Weighted-Ensemble Precipitation (MSWEP), Climate
Forecast System Reanalysis (CFSR) for the atmospheric circulation
data, precipitationevaporation and vertical velocity (omega) data
from the ERA-Interim reanalysis, SST data from Reynolds series and
the Vegetation Health Index (VHI) estimated from satellite data.
Analyses for the vegetation, precipitation and
precipitationevaporation data were based on statistic aspects such
as angular coefficients and p value of their quarterly and annual
temporal series, which were created using a threshold to specify,
in percentage, drought conditions over the country. Temporal
series that pointed out an increase in the drought areas were
chosen to create composites for the other variables, such as
circulation, SST and vertical velocity. An expressive increase of
the areas affected by droughts conditions was showed in the anual
VHI series for the entire period of study, as well as for the last
decade in the decenal VHI series. These aspects were reproduced in
the quarterly series for the austral summer (DJF), in all indexes
analyzed, specially in the last decenal period (2007/08 -
2015/16). The composites for the SST and atmospheric circulation
anomalies indicated that ENSO (El Niņo-Southern Oscillation)
events were associated with anomalous anticyclonic circulation
patterns, especially in the last three years of the decenal serie
(2014, 2015 and 2016). Its combined occurrence played an important
role in the maintenance and expansion of the areas affected by
drought conditions during the summer of the last decenal period,
contributing to the increasing of the total area.",
committee = "Arav{\'e}quia, Jos{\'e} Antonio (presidente) and Coelho, Caio
Augusto dos Santos (orientador) and Santos, Renata Libonati dos",
englishtitle = "Spatial and temporal characterization of droughts over Brazil in
last decades (1981-2016)",
language = "pt",
pages = "132",
ibi = "8JMKD3MGP3W34R/3TRGGPL",
url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3TRGGPL",
targetfile = "publicacao.pdf",
urlaccessdate = "26 abr. 2024"
}