Aplicação do Método Cadeia de Markov à ocorrência de temperatura mínima do ar no Estado do Rio Grande do Sul

Abstract

The minimum air temperature is one of the meteorological variables which exerts relevant influence over environmental conditions, being one of the limiting factors to the growth and development of the plants. The evaluation of the minimum air temperature is directly related to the identification of the more adequate periods for the sowing of the various cultivation, bacause it permits the establishment of the critical plant phase to coincide with the period of a minor probability of harmful temperature occurrence to the cultivation. Through the thirty years of daily data study of the minimum air temperature, in twelve surface meteorological stations, in the State of Rio Grande do Sul, during the spring and summer months, the period of characterization was done with a minimum temperature within the following intervals: (0ºC < t < 5ºC), (5ºC < t < 10ºC) and (10ºC < t < 15ºC). The probability of minimum temperature to be found in the referred intervals, was obtained through the calculation of the conditional probability and the probability of occurrence of days the minimum temperature within an interval of seven days, using the first-order Markov Chain Model. The results obtained showed that the probability of a determined day to be found at a minimum particular temperature depends on the precedent state, confirming, satisfactorily, the adjustment of the Markov Chain Model.