Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption
Autor(a) principal: | |
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Data de Publicação: | 2012 |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Bragantia |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052012000100018 |
Resumo: | The aim of this study was to describe monthly series of the Standardized Precipitation Index obtained from four weather stations of the State of São Paulo, Brazil. The analyses were carried out by evaluating the normality assumption of the SPI distributions, the spectral features of these series and, the presence of climatic trends in these datasets. It was observed that the Pearson type III distribution was better than the gamma 2-parameter distribution in providing monthly SPI series closer to the normality assumption inherent to the use of this standardized index. The spectral analyses carried out in the time-frequency domain did not allow us to establish a dominant mode in the analyzed series. In general, the Mann-Kendall and the Pettitt tests indicated the presence of no significant trend in the SPI series. However, both trend tests have indicated that the temporal variability of this index, observed at the months of October over the last 60 years, cannot be seen as the result of a purely random process. This last inference is due to the concentration of decreasing trends, with a common beginning (1983/84) in the four locations of the study. |
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Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumptionPearson type III distributiondroughtclimate trendsThe aim of this study was to describe monthly series of the Standardized Precipitation Index obtained from four weather stations of the State of São Paulo, Brazil. The analyses were carried out by evaluating the normality assumption of the SPI distributions, the spectral features of these series and, the presence of climatic trends in these datasets. It was observed that the Pearson type III distribution was better than the gamma 2-parameter distribution in providing monthly SPI series closer to the normality assumption inherent to the use of this standardized index. The spectral analyses carried out in the time-frequency domain did not allow us to establish a dominant mode in the analyzed series. In general, the Mann-Kendall and the Pettitt tests indicated the presence of no significant trend in the SPI series. However, both trend tests have indicated that the temporal variability of this index, observed at the months of October over the last 60 years, cannot be seen as the result of a purely random process. This last inference is due to the concentration of decreasing trends, with a common beginning (1983/84) in the four locations of the study.Instituto Agronômico de Campinas2012-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052012000100018Bragantia v.71 n.1 2012reponame:Bragantiainstname:Instituto Agronômico de Campinas (IAC)instacron:IAC10.1590/S0006-87052012005000004info:eu-repo/semantics/openAccessBlain,Gabriel Constantinoeng2012-05-11T00:00:00Zoai:scielo:S0006-87052012000100018Revistahttps://www.scielo.br/j/brag/https://old.scielo.br/oai/scielo-oai.phpbragantia@iac.sp.gov.br||bragantia@iac.sp.gov.br1678-44990006-8705opendoar:2012-05-11T00:00Bragantia - Instituto Agronômico de Campinas (IAC)false |
dc.title.none.fl_str_mv |
Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption |
title |
Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption |
spellingShingle |
Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption Blain,Gabriel Constantino Pearson type III distribution drought climate trends |
title_short |
Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption |
title_full |
Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption |
title_fullStr |
Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption |
title_full_unstemmed |
Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption |
title_sort |
Monthly values of the standardized precipitation index in the State of São Paulo, Brazil: trends and spectral features under the normality assumption |
author |
Blain,Gabriel Constantino |
author_facet |
Blain,Gabriel Constantino |
author_role |
author |
dc.contributor.author.fl_str_mv |
Blain,Gabriel Constantino |
dc.subject.por.fl_str_mv |
Pearson type III distribution drought climate trends |
topic |
Pearson type III distribution drought climate trends |
description |
The aim of this study was to describe monthly series of the Standardized Precipitation Index obtained from four weather stations of the State of São Paulo, Brazil. The analyses were carried out by evaluating the normality assumption of the SPI distributions, the spectral features of these series and, the presence of climatic trends in these datasets. It was observed that the Pearson type III distribution was better than the gamma 2-parameter distribution in providing monthly SPI series closer to the normality assumption inherent to the use of this standardized index. The spectral analyses carried out in the time-frequency domain did not allow us to establish a dominant mode in the analyzed series. In general, the Mann-Kendall and the Pettitt tests indicated the presence of no significant trend in the SPI series. However, both trend tests have indicated that the temporal variability of this index, observed at the months of October over the last 60 years, cannot be seen as the result of a purely random process. This last inference is due to the concentration of decreasing trends, with a common beginning (1983/84) in the four locations of the study. |
publishDate |
2012 |
dc.date.none.fl_str_mv |
2012-01-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052012000100018 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052012000100018 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0006-87052012005000004 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Instituto Agronômico de Campinas |
publisher.none.fl_str_mv |
Instituto Agronômico de Campinas |
dc.source.none.fl_str_mv |
Bragantia v.71 n.1 2012 reponame:Bragantia instname:Instituto Agronômico de Campinas (IAC) instacron:IAC |
instname_str |
Instituto Agronômico de Campinas (IAC) |
instacron_str |
IAC |
institution |
IAC |
reponame_str |
Bragantia |
collection |
Bragantia |
repository.name.fl_str_mv |
Bragantia - Instituto Agronômico de Campinas (IAC) |
repository.mail.fl_str_mv |
bragantia@iac.sp.gov.br||bragantia@iac.sp.gov.br |
_version_ |
1754193302749446144 |