Transformada em ondeletas para projeções de vazões em médio prazo no sistema nacional interconectado

• Autor(a) principal: Sousa Lima, Carlos Eduardo
• Data de Publicação: 2021
• Outros Autores: Maciel da Silva, Marx Vinicius, da Silva Silveira, Cleiton, Vasconcelos Junior, Francisco das Chagas
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Brasileira de Ciências Ambientais (Online)
• Texto Completo: https://www.rbciamb.com.br/Publicacoes_RBCIAMB/article/view/1048
• topic: ondeletas autoregressivas; Sistema Nacional Interconectado; variabilidade climática; projeção de vazão.; autoregressive wavelets; National Interconnected System; climate variability; streamflow projection.

This study aimed to analyze the variability of average annual streamflow time series of the National Interconnected System (NIS) (Brazil) and create a projection model of future streamflow scenarios from 3 to 10 years using wavelet transform (WT). The streamflow time series were used and divided into two periods, namely, 1931–2005 and 2006–2017, for calibration and verification, respectively. The annual series was standardized, and by the WT, it was decomposed into two bands plus the residue for each base posts (BP) for later reconstruction. Then, an autoregressive (AR) model per band and residue was made. The projection was obtained by adding the AR models. For performance evaluation, a qualitative analysis of the cumulative probability distribution of the projected years and an analysis of the likelihood were performed. The model identified the probability distribution function of the projected years and obtained a likelihood ratio of > 1 in most SIN regions, indicating that this methodology can capture the mediumrange variability.