Trends in daily precipitation in highlands region of Santa Catarina, southern Brazil

Abstract

This study evaluates the occurrence of trends in time series of precipitation in the highlands region of Santa Catarina, Southern Brazil. Daily precipitation data of three weather stations at Lages, São Joaquim and Campos Novos were used to evaluate rainfall trends. The trends were analyzed through the Seasonal Mann Kendall test, to include occurrence of maximum annual 1-day precipitation (RX1), maximum annual consecutive 2-day precipitation (RX2) and maximum annual consecutive 3-day precipitation (RX3) and evaluation of Rainfall Anomaly Index (RAI). Trends were identified in two of three weather stations investigated. Positive precipitation trends were found in the spring and winter for Lages, and in the spring and summer for São Joaquim. Also, there is a trend of increase in the RX1, RX2 and RX3 frequencies and an increase in positive anomalies in the last decade for these stations. There are no statistically significant trends in the precipitation of Campos Novos, which may be associated with the short series of available data for the analysis. The occurrence of El Niño phenomenon with moderate to strong intensity was usually associated with the occurrence of positive precipitation anomalies and the La Niña phenomenon was related to the occurrence of negative anomalies. However, the influence of La Niña in the periods of negative anomaly has been reduced since the beginning of the 21st century.Keywords: anomaly, rainfall, Mann-Kendall. Tendências na precipitação diária da região serrana de SantaCatarina, sul do Brasil RESUMOEste estudo tem como objetivo avaliar a ocorrência de tendências em séries temporais de precipitação na região serrana de Santa Catarina, no sul do Brasil. As tendências foram analisadas através do teste Sazonal de Mann Kendall, frequências da precipitação máxima de 1 dia (RX1), precipitação máxima consecutiva de 2 dias (RX2) e precipitação máxima consecutiva de 3 dias (RX3) e avaliação do Índice de Anomalia de Chuva (RAI). Tendências foram identificadas em duas das três estações meteorológicas investigadas. As tendências 2 Eder Alexandre Schatz Sá et al.Rev. Ambient. Água vol. 13 n. 1, e2149 -Taubaté 2018 positivas de precipitação foram encontradas na primavera e no inverno para Lages e na primavera e verão para São Joaquim. Além disso, há uma tendência de aumento das RX1, RX2 e RX3 e aumento de anomalias positivas na última década para essas estações. Não há tendências estatisticamente significativas na precipitação de Campos Novos, o que pode estar associado à curta série de dados disponíveis para a análise. A ocorrência do fenômeno de El Niño com intensidade moderada a forte geralmente foi associada à ocorrência de anomalias de precipitação positivas e o fenômeno de La Niña estava relacionado à ocorrência de anomalias negativas. Embora, observe-se que a influência de La Niña nos períodos de anomalia negativa foi reduzida desde o início do século XXI.Palavras-chave: anomalia, chuva, Mann-Kendall.

Generalized Pareto distribution applied to the analysis of maximum rainfall events in Uruguaiana, RS, Brazil

“…(1) the first scenario generates samples of the Exponential distribution with the estimated parameters, and 2the second scenario generates samples of the GPD with the estimated parameters. Each scenario [(k = (1), (2)] is repeated 10000 times, according to the Monte Carlo simulation procedure, following the steps described below:…”

“…Furthermore, the series of monthly highs are independent, with 1% level of significance. We should highlight that we have used these tests to verify the assumptions of the Extreme Value Theory models, but that they could be used for other interests, such as [2,29,34] in the trend analysis of hydro-climatic series. In addition, the Kolmogorov-Smirnov test states that both distributions were fitted in all months and the QQ plots corroborate the results (Fig.…”

“…Rainfall is vital for life on Earth [1], but its occurrence in high magnitude can cause damage and losses, usually causing flooding, destruction of buildings and crops, soil erosion, breaches of dikes and dams, among others [2,3]. Damage in cities tends to be more severe because of the rapid urbanization and installation of complex infrastructure [4].…”

“…Damage in cities tends to be more severe because of the rapid urbanization and installation of complex infrastructure [4]. In addition, the frequency of extreme weather events has shown an increasing trend in various regions of the planet [2,5]. In addition, the frequency of extreme weather events has shown an increasing trend in several regions of the planet [6][7][8], and the southern region of Brazil has suffered from the occurrence of these events [2,5].…”

Tendências e Variabilidades nas Séries Históricas de Precipitação Mensal e Anual no Bioma Cerrado no Período 1977-2010

“…Na América do Sul, observações indicam que nas últimas décadas houve um aumento da precipitação na região norte e redução na região sul (Lee et al 2011). No Brasil, as pesquisas mostram que tem ocorrido nas últimas quatro décadas um aumento de chuvas na região sul e sudeste, enquanto que o centro-norte do país tem apresentado tendências de redução da precipitação (Ávila et al 2016;Salviano et al 2016;Zandonadi et al 2016;Sá et al 2018).…”