Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna)
The Brazilian savanna (Cerrado) is the second-largest biome in Brazil, following the Amazon. The influence of climate in this biome is pronounced, dry winters and rainy summers determines the characteristics of the Cerrado typologies. The effect of climate on vegetation can be assessed through the v...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | Brasil |
| Institución: | Universidade Federal de Viçosa (UFV) |
| Repositorio: | LOCUS Repositório Institucional da UFV |
| Idioma: | inglés |
| OAI Identifier: | oai:locus.ufv.br:123456789/28744 |
| Acceso en línea: | https://locus.ufv.br//handle/123456789/28744 |
| Access Level: | acceso abierto |
| Palabra clave: | Fenologia Sensoriamento remoto Cerrados Vegetação - Mapeamento - Índices Fotointerpretação Florestal |
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Brasil |
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| dc.title.none.fl_str_mv |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna) |
| title |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna) |
| spellingShingle |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna) Oliveira, Brener de Almeida Fenologia Sensoriamento remoto Cerrados Vegetação - Mapeamento - Índices Fotointerpretação Florestal |
| title_short |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna) |
| title_full |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna) |
| title_fullStr |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna) |
| title_full_unstemmed |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna) |
| title_sort |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna) |
| dc.creator.none.fl_str_mv |
Oliveira, Brener de Almeida |
| author |
Oliveira, Brener de Almeida |
| author_facet |
Oliveira, Brener de Almeida |
| author_role |
author |
| dc.contributor.none.fl_str_mv |
Amaral, Cibele Hummel do http://lattes.cnpq.br/3640221356088662 |
| dc.subject.por.fl_str_mv |
Fenologia Sensoriamento remoto Cerrados Vegetação - Mapeamento - Índices Fotointerpretação Florestal |
| topic |
Fenologia Sensoriamento remoto Cerrados Vegetação - Mapeamento - Índices Fotointerpretação Florestal |
| description |
The Brazilian savanna (Cerrado) is the second-largest biome in Brazil, following the Amazon. The influence of climate in this biome is pronounced, dry winters and rainy summers determines the characteristics of the Cerrado typologies. The effect of climate on vegetation can be assessed through the variation in biophysical responses of each Cerrado typology provided by time-series of spectral indices as Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). This study aims to test for the correlation between rainfall and Cerrado typologies spectral responses from 2001 to 2018, in central Brazil. As specific objectives, we intend to spectrally separate such physiognomies and characterize them according to their phenological metrics. Thus, we performed a Principal Component Analysis (PCA) for the MOD13Q1 NDVI and EVI time-series, to test for the spectral separation of Cerrado typologies. We extracted the phenological metrics (e.g. growth rate, base value) in TIMESAT software for both indices time-series, in order to investigate the seasonal behavior of the different vegetation types. Further, we performed wavelet analyses for EVI and NDVI and rainfall time-series in order to detect whether there are anomalies in the series and whether there are coherence and causal relationships between vegetation spectral response and rainfall. PCA showed a clear spectral-temporal separation among forest and savanna physiognomies. Our findings indicated that phenological metrics are efficient in characterizing the seasonal behavior of the Cerrado typologies, and forest-like ones have greater total productivity of green biomass compared to the savanna types. Moreover, we observed coherence between vegetation response and rainfall, in the short-run (32 to 64 and 64 to 128 days). The middle-run wavelet analyses showed a cyclical correlation and coherence between phenology of the physiognomies and rainfall in every 8.5 months. The wavelet NDVI data present an in-phase situation where vegetation leads to rainfall. Conversely, in the long-run, another in-phase is observed and rainfall leads vegetation response. For EVI data, we did not observe any leading phase in the long-run. We concluded that it is possible to separate the Cerrado typologies by their spectral- temporal biophysical responses, enabling the distinction between savanna and forest physiognomies, which show the highest seasonal productivity. It is also possible to conclude that there is a strong seasonal relationship between rainfall and vegetation biophysical response throughout the time, and that extreme events and long-term trends of rainfall also show coherence with vegetation. These findings suggest that, any rainfall regime change impacts the green biomass productivity of various Cerrado biome physiognomies, from the less productive savannas to the most productive forest patches. Keywords: Remote sensing. Phenology. Cerrado. TIMESAT. NDVI and EVI. |
| publishDate |
2020 |
| dc.date.none.fl_str_mv |
2020-02-19 2022-03-11T12:53:06Z 2022-03-11T12:53:06Z |
| dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
| dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
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masterThesis |
| status_str |
publishedVersion |
| dc.identifier.uri.fl_str_mv |
OLIVEIRA, Brener de Almeida. Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna). 2020. 55 f. Dissertação (Mestrado em Ciência Florestal) - Universidade Federal de Viçosa, Viçosa. 2020. https://locus.ufv.br//handle/123456789/28744 |
| identifier_str_mv |
OLIVEIRA, Brener de Almeida. Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna). 2020. 55 f. Dissertação (Mestrado em Ciência Florestal) - Universidade Federal de Viçosa, Viçosa. 2020. |
| url |
https://locus.ufv.br//handle/123456789/28744 |
| dc.language.iso.fl_str_mv |
eng |
| language |
eng |
| dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
| eu_rights_str_mv |
openAccess |
| dc.format.none.fl_str_mv |
application/pdf |
| dc.publisher.none.fl_str_mv |
Universidade Federal de Viçosa |
| publisher.none.fl_str_mv |
Universidade Federal de Viçosa |
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reponame:LOCUS Repositório Institucional da UFV instname:Universidade Federal de Viçosa (UFV) instacron:UFV |
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Universidade Federal de Viçosa (UFV) |
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UFV |
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UFV |
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LOCUS Repositório Institucional da UFV |
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LOCUS Repositório Institucional da UFV |
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LOCUS Repositório Institucional da UFV - Universidade Federal de Viçosa (UFV) |
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fabiojreis@ufv.br |
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1853667130762854400 |
| spelling |
Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna)FenologiaSensoriamento remotoCerradosVegetação - Mapeamento - ÍndicesFotointerpretação FlorestalThe Brazilian savanna (Cerrado) is the second-largest biome in Brazil, following the Amazon. The influence of climate in this biome is pronounced, dry winters and rainy summers determines the characteristics of the Cerrado typologies. The effect of climate on vegetation can be assessed through the variation in biophysical responses of each Cerrado typology provided by time-series of spectral indices as Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). This study aims to test for the correlation between rainfall and Cerrado typologies spectral responses from 2001 to 2018, in central Brazil. As specific objectives, we intend to spectrally separate such physiognomies and characterize them according to their phenological metrics. Thus, we performed a Principal Component Analysis (PCA) for the MOD13Q1 NDVI and EVI time-series, to test for the spectral separation of Cerrado typologies. We extracted the phenological metrics (e.g. growth rate, base value) in TIMESAT software for both indices time-series, in order to investigate the seasonal behavior of the different vegetation types. Further, we performed wavelet analyses for EVI and NDVI and rainfall time-series in order to detect whether there are anomalies in the series and whether there are coherence and causal relationships between vegetation spectral response and rainfall. PCA showed a clear spectral-temporal separation among forest and savanna physiognomies. Our findings indicated that phenological metrics are efficient in characterizing the seasonal behavior of the Cerrado typologies, and forest-like ones have greater total productivity of green biomass compared to the savanna types. Moreover, we observed coherence between vegetation response and rainfall, in the short-run (32 to 64 and 64 to 128 days). The middle-run wavelet analyses showed a cyclical correlation and coherence between phenology of the physiognomies and rainfall in every 8.5 months. The wavelet NDVI data present an in-phase situation where vegetation leads to rainfall. Conversely, in the long-run, another in-phase is observed and rainfall leads vegetation response. For EVI data, we did not observe any leading phase in the long-run. We concluded that it is possible to separate the Cerrado typologies by their spectral- temporal biophysical responses, enabling the distinction between savanna and forest physiognomies, which show the highest seasonal productivity. It is also possible to conclude that there is a strong seasonal relationship between rainfall and vegetation biophysical response throughout the time, and that extreme events and long-term trends of rainfall also show coherence with vegetation. These findings suggest that, any rainfall regime change impacts the green biomass productivity of various Cerrado biome physiognomies, from the less productive savannas to the most productive forest patches. Keywords: Remote sensing. Phenology. Cerrado. TIMESAT. NDVI and EVI.A savana brasileira (Cerrado) é o segundo maior bioma do Brasil, depois da Amazônia. A influência do clima neste bioma é acentuada, invernos secos e verões chuvosos determinam as características das tipologias do Cerrado. O efeito do clima na vegetação pode ser avaliado através da variação nas respostas biofísicas de cada tipologia do Cerrado, fornecida por séries temporais de índices espectrais como Índice de Vegetação por Diferenças Normalizadas (NDVI) e Índice de Vegetação Aprimorado (EVI). Este estudo tem como objetivo testar a correlação entre as respostas espectrais das tipologias do Cerrado de 2001 a 2018 e eventos de precipitação no Brasil central. Como objetivos específicos, pretendeu-se separar espectralmente essas fisionomias e caracterizá-las de acordo com suas métricas fenológicas. Assim, foi realizada uma Análise de Componentes Principais (PCA) para as séries temporais MOD13Q1 NDVI e EVI, para testar a separação espectral das tipologias do Cerrado. Extraíu-se as métricas fenológicas (por exemplo, taxa de crescimento, valor base) no software TIMESAT para os dois índices de séries temporais, a fim de investigar o comportamento sazonal dos diferentes tipos de vegetação. Além disso, realizou-se análises de wavelets para EVI e NDVI e séries temporais de chuvas, a fim de detectar se há anomalias na série e se há coerência e relação causal entre a resposta espectral da vegetação e a precipitação. O PCA mostrou uma clara separação espectro- temporal entre as fisionomias das florestas e das savanas. Os resultados indicaram que as métricas fenológicas são eficientes na caracterização do comportamento sazonal das tipologias do Cerrado, e as do tipo floresta têm maior produtividade total da biomassa verde em comparação às do tipo savana. Além disso, observou-se coerência entre a resposta da vegetação e as chuvas, no curto prazo (32 a 64 e 64 a 128 dias). As análises de ondas médias mostraram correlação cíclica e coerência entre a fenologia das fisionomias e chuvas a cada 8,5 meses. As wavelet para dados de NDVI apresentam uma situação em fase em que a vegetação leva à precipitação. De maneira inversa, no longo prazo outra fase é observada onde a precipitação leva à resposta da vegetação. Para os dados do EVI, não foi observado nenhuma fase no longo prazo. Concluiu-se que é possível separar as tipologias de Cerrado por suas respostas biofísicas espectral-temporais, possibilitando a distinção entre savana e fisionomias florestais, as quais apresentam maior produtividade sazonal. Também é possível concluir que existe uma forte relação sazonal entre a chuva e a resposta biofísica da vegetação ao longo do tempo, e que eventos extremos e tendências de chuva a longo prazo também mostram coerência com a vegetação. Esses achados sugerem que qualquer mudança no regime de chuvas impacta a produtividade da biomassa verde de várias fisionomias do bioma Cerrado, desde as savanas menos produtivas até os fragmentos florestais mais produtivos. Palavras-chave: Sensoriamento remoto. Fenologia. Cerrado. TIMESAT. NDVI e EVI.Conselho Nacional de Desenvolvimento Científico e TecnológicoUniversidade Federal de ViçosaAmaral, Cibele Hummel dohttp://lattes.cnpq.br/36402213560886622022-03-11T12:53:06Z2022-03-11T12:53:06Z2020-02-19info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfOLIVEIRA, Brener de Almeida. Time series investigation for correlations between rainfall and phenology in Cerrado (Brazilian savanna). 2020. 55 f. Dissertação (Mestrado em Ciência Florestal) - Universidade Federal de Viçosa, Viçosa. 2020.https://locus.ufv.br//handle/123456789/28744enginfo:eu-repo/semantics/openAccessreponame:LOCUS Repositório Institucional da UFVinstname:Universidade Federal de Viçosa (UFV)instacron:UFVOliveira, Brener de Almeida2024-07-12T07:25:05Zoai:locus.ufv.br:123456789/28744Repositório InstitucionalPUBhttps://www.locus.ufv.br/oai/requestfabiojreis@ufv.bropendoar:21452024-07-12T07:25:05LOCUS Repositório Institucional da UFV - Universidade Federal de Viçosa (UFV)false |
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15,301629 |