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@PhDThesis{Anchayhua:2020:AnEsTe,
               author = "Anchayhua, Rosario Julieta Altamirano",
                title = "An{\'a}lise espacial e temporal de eventos extremos secos e 
                         chuvosos e circula{\c{c}}{\~a}o atmosf{\'e}rica",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2020",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2018-05-25",
             keywords = "Amaz{\^o}nia, agrupamento, SPI, eventos extremos, limiares de 
                         precipita{\c{c}}{\~a}o, Amazon, clustering, extreme events, 
                         precipitation thresholds.",
             abstract = "Este estudo tem por objetivo fazer uma an{\'a}lise espacial e 
                         temporal dos eventos extremos secos e chuvosos na bacia 
                         Amaz{\^o}nica. Para isto, a t{\'e}cnica de agrupamento 
                         (m{\'e}todo de Ward) {\'e} utilizada para identificar 
                         sub-regi{\~o}es pluviom{\'e}tricas homog{\^e}neas. Foram 
                         calculados e avaliados tr{\^e}s {\'{\i}}ndices de seca: 
                         {\'{\I}}ndice de Severidade da Seca de Palmer autocalibrado 
                         (scPDSI), {\'{\I}}ndice de Precipita{\c{c}}{\~a}o e 
                         vapotranspira{\c{c}}{\~a}o Normalizado (SPEI) e {\'{\I}}ndice 
                         de Precipita{\c{c}}{\~a}o Normalizado (SPI) utilizados para 
                         identificar e caracterizar eventos de secas e chuvas nestas 
                         sub-regi{\~o}es. Dados da rean{\'a}lise ERA-Interim e do GPCC 
                         foram usados para caracterizar (espa{\c{c}}o/temporal), 
                         atrav{\'e}s da an{\'a}lise de agrupamentos e os {\'{\i}}ndices 
                         de seca, os eventos extremos mais relevantes no per{\'{\i}}odo 
                         1979-2013. Foram encontradas 5 sub-regi{\~o}es homog{\^e}neas 
                         sobre a bacia: Norte, Noroeste, Central, Sudeste e Sul. Os 
                         resultados mostraram que os ciclos anuais de 
                         precipita{\c{c}}{\~a}o em todas sub-regi{\~o}es foram coerentes 
                         com o desenvolvimento e a manuten{\c{c}}{\~a}o da 
                         convec{\c{c}}{\~a}o profunda entre setembro e maio na 
                         regi{\~a}o amaz{\^o}nica. Na an{\'a}lise de desempenho entre os 
                         {\'{\i}}ndices de seca e a precipita{\c{c}}{\~a}o, o SPI foi 
                         melhor em compara{\c{c}}{\~a}o dos outros {\'{\i}}ndices. As 
                         sub-regi{\~o}es Norte, Noroeste e Centro (Sul) mostraram 
                         tend{\^e}ncias positivas (negativas) na precipita{\c{c}}{\~a}o 
                         e com os {\'{\i}}ndices. A an{\'a}lise espacial e temporal dos 
                         SPI nas diferentes escalas e sub-regi{\~o}es identificaram os 
                         principais eventos extremos de seca (1982-83; 1992; 1997-98; 2005 
                         e 2010) e inunda{\c{c}}{\~o}es (1989, 1999, 2009 e 2012). 
                         Contudo, estes eventos mostraram diferentes 
                         caracter{\'{\i}}sticas em cada sub-regi{\~a}o. A 
                         Sub-regi{\~a}o Noroeste mostrou menor varia{\c{c}}{\~a}o nas 
                         escalas do SPI, pelo que ocorreram poucos eventos chuvosos e secos 
                         devido ao fato da precipita{\c{c}}{\~a}o ser uniformemente 
                         distribu{\'{\i}}da ao longo do ano. As Sub-regi{\~o}es Sudeste 
                         e Sul mostraram alta variabilidade nas escalas do SPI devido 
                         {\`a} presen{\c{c}}a da marcante esta{\c{c}}{\~a}o seca e 
                         chuvosa, por{\'e}m com maior ocorr{\^e}ncia de eventos secos e 
                         chuvosos. Os resultados apontam que, os eventos secos e chuvosos 
                         apresentaram diferen{\c{c}}as na frequ{\^e}ncia, 
                         dura{\c{c}}{\~a}o, severidade e intensidade tanto temporalmente 
                         como espacialmente. Verificam-se dois per{\'{\i}}odos marcantes: 
                         a d{\'e}cada de 80s e 90s que caracterizou eventos mais 
                         duradouros associados a um aumento ou d{\'e}ficit progressivo da 
                         precipita{\c{c}}{\~a}o durante longo tempo, e nos 2000 foram 
                         curtos decorrente do aumento ou d{\'e}ficit dr{\'a}stico da 
                         precipita{\c{c}}{\~a}o em curto tempo. Infere-se que a bacia 
                         apresente ciclos secos e chuvosos, em vez de uma tend{\^e}ncia 
                         como caracter{\'{\i}}stica das chuvas na Amaz{\^o}nia. Foi 
                         revelado {\'a}reas de eventos secos (chuvosos) com maior 
                         frequ{\^e}ncia, dura{\c{c}}{\~o}es, severidades e intensidades 
                         ficaram no lado oriental (ocidental) da bacia. Evidenciou-se que a 
                         ocorr{\^e}ncia dos eventos secos e chuvosos nas sub-regi{\~o}es 
                         Norte, Noroeste, Centro e Sudeste se associam aos eventos ENOS. Os 
                         resultados n{\~a}o mostraram correla{\c{c}}{\~a}o entre as 
                         anomalias das escalas do SPI e a TSM na sub-regi{\~a}o Sul 
                         merecendo mais aten{\c{c}}{\~a}o em estudos posteriores. 
                         Conclui-se que ambos os limiares de precipita{\c{c}}{\~a}o e SPI 
                         s{\~a}o complement{\'a}rios para caracterizar os eventos 
                         extremos: secos e chuvosos e sugere-se seu uso para monitorar 
                         esses eventos como apontados pelas refer{\^e}ncias citadas neste 
                         estudo. ABSTRACT: This study aims to make a spatial and temporal 
                         analysis of extreme dry and rainy events in the Amazon basin. For 
                         this, the grouping technique (Ward method) is used to identify 
                         homogeneous pluviometric sub-regions. Three drought indices were 
                         calculated and evaluated: Palmer Drought Severity Index 
                         self-calibrated (scPDSI), Precipitation Index and Normalized 
                         Evapotranspiration (SPEI) and Normalized Precipitation Index (SPI) 
                         were used to identify and characterize drought and rainfall events 
                         in these subregions. Data from the ERA-Interim and GPCC reanalysis 
                         were used to characterize (space/time), through cluster analysis 
                         and drought indexes, the most relevant extreme events in the 
                         period 1979-2013. The results showed that the annual precipitation 
                         cycles in all subregions were consistent with the development and 
                         maintenance of deep convection between September and May in the 
                         Amazon region. In the performance analysis between indexes and 
                         precipitation, SPI was better in comparison to the other indices. 
                         The North, Northwest and Center (South) subregions showed positive 
                         (negative) trends in precipitation and with indices. The spatial 
                         and temporal analysis of SPI in the different scales and 
                         subregions identified the main extreme events of drought (1982-83, 
                         1992, 1997-98, 2005 and 2010) and floods (1989, 1999, 2009 and 
                         2012). However, these events showed different characteristics in 
                         each subregion. The Northwest Subregion showed lower variation in 
                         SPI scales, so there were few rainy and dry events due to the fact 
                         that precipitation was evenly distributed throughout the year. The 
                         Southeast and South Sub-regions showed high variability in the SPI 
                         scales due to the presence of the marked dry and rainy season, but 
                         with more occurrence of dry and rainy events. The results indicate 
                         that the dry and rainy events presented differences in frequency, 
                         duration, severity and intensity both temporally and spatially. 
                         There are two major periods: the 1980s and 1990s that 
                         characterized more long-lasting events associated with a 
                         progressive increase or deficit of precipitation over a long 
                         period of time, and in the 2000s were short due to the increase or 
                         drastic deficit of precipitation in a short time. It is inferred 
                         that the basin presents dry and rainy cycles, instead of a 
                         tendency as characteristic of rainfall in the Amazon. Areas of dry 
                         (rainy) events were revealed more frequently, durations, 
                         severities and intensities were found on the eastern (western) 
                         side of the basin. It was evidenced that the occurrence of dry and 
                         rainy events in the North, Northwest, Central and Southeast 
                         subregions are associated with ENSO events. The results showed no 
                         correlation between the SPI and SST anomalies in the southern 
                         subregion, deserving more attention in later studies. It is 
                         concluded that both precipitation thresholds and SPI are 
                         complementary to characterize the extreme events: dry and rainy 
                         and its use is suggested to monitor these events as indicated by 
                         the references cited in this study.",
            committee = "Orsini, Jos{\'e} Ant{\^o}nio Marengo (presidente) and Fernandez, 
                         Julio Pablo Reyes (orientador) and Manzi, Antonio Ocimar and 
                         Silva, Maria Elisa Siqueira and Vasques, Ana Carolina",
         englishtitle = "Spatial and temporal analysis of extreme dry and wet events in 
                         Amazon and associated atmospheric circulation",
             language = "pt",
                pages = "229",
                  ibi = "8JMKD3MGP3W34R/3R54RKH",
                  url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3R54RKH",
           targetfile = "publicacao.pdf",
        urlaccessdate = "29 mar. 2024"
}


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