Data/hora: 16/06/2024 07:43:34

Biblioteca(s): | Epagri-Sede.
Data corrente: | 11/11/2014
Data da última atualização: | 11/11/2014
Autoria: | BACK, A. J.; COAN, B. P.
Título: | Mathematical modeling of the sequence of dry days and rainy days in Curitibanos, SC.
Ano de publicação: | 2014
Fonte/Imprenta: | In: CONGRESSO BRASILEIRO DE METEOROLOGIA, 18., 2014, Recife. Anais ... Rio de Janeiro: SBMET, 2014.
Idioma: | Português
Conteúdo: | Knowledge of the distribution of rainfall in time and space plays an important role to make decision in agriculture and other field activities. This work aimed to make the mathematical modeling of the sequence of dry days and rainy days for Curitibanos, SC. Daily rainfall data were used for the period 1970-2012, from the National Water Agency (ANA), pluviometer code 02750009, latitude 27 ° 20'02 "S, longitude 50 ° 45'12" W and altitude 829 meters, located in the municipality of Curitibanos. For modeling the occurrence of precipitation was considered a Markov chain of two states, where the day is considered dry or rainy. The criterion to be a dry day was less than 1.0 mm rain. In this work the chain of first order was used, where the probability of one day to be dry (or rainy) depends only on the day before. To take into account the seasonality of rainfall, the model parameters were adjusted for monthly periods, and thus calculated the transition probabilities of dry and wet days for each month. To simulate the sequence of dry and rainy days the geometric distribution was used. Adherence of sequences of consecutive dry days and rainy days to the adjusted series distributions were evaluated using the Kolmogorov-Smirnov test (KS) at a significance level of 5%. For every month statistics values of the KS test Dmax were below the critical value (Dcrit 0.217). The greatest value of the Dmax (Dmax = 0.070) was observed in August indicating maximum difference of 7% between the observed and estimated frequencies. As the Dcrit values were higher than the values of Dmax in all months, it was accepted the hypothesis of equality of the theoretical and empirical distributions, and conclude that the geometric distribution can be used to estimate the probabilities of sequences of rainy days or dry days. For the sequence of rainy days the maximum value of the statistic Dmax was observed in September (Dmax = 0.0954) significantly lower than the critical values (Dcrit = 0.432). The values of probability up to 3, 5 to 7 consecutive rainy days, as well as 5, 7 and 10 consecutive dry days were presented. It can be concluded that the probabilities of occurrences of consecutive dry days and consecutive rainy days in Curitibanos can be estimated using the geometric distribution.
Palavras-Chave: | geometric distribution; Markov chains; rainfall.
Categoria do assunto: | P Recursos Naturais, Ciências Ambientais e da Terra
URL: | http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_35107.pdf
Registro original: | Epagri-Sede (Epagri-Sede)
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