A Brief multifractal analysis of rainfall dynamics in Piracicaba, São Paulo, Brazil

• Autor(a) principal: Xavier Júnior, Sílvio Fernando Alves
• Data de Publicação: 2018
• Outros Autores: Stosic, Tatijana, Stosic, Borko, Jale, Jader Da Silva, Xavier, Érika Fialho Morais
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Acta scientiarum. Technology (Online)
• Texto Completo: http://www.periodicos.uem.br/ojs/index.php/ActaSciTechnol/article/view/35116
• topic: rainfall; power law; MF-DFA.

The aim of this study was to evaluate the statistical properties of a daily rainfall time series recorded in Piracicaba river basin, state of Sao Paulo, Brazil in the period 1917-2016. We apply Multifractal Detrended Fluctuation Analysis (MF-DFA) on deseasonalized data and calculate generalized scaling exponents, h(q). We find that h(q) is a decreasing function of q, indicating multifractal behavior of precipitation dynamics. We also perform calculations on two subseries corresponding to the periods before and after 1970, where the second period is characterised by a significant increase of positive trend in rainfall intensity. We find no significant change in behaviour between these two subseries and the entire series, indicating that the dynamics of the underlying process did not change. Our results agree with previous studies on multifractal properties of rainfall time series in other regions of the world supporting the hypotheses of the existence of multiplicative cascade processes in the atmosphere.