Search

The objectives of this work were to verify the adjustment of time series of monthly minimum (Tmín) and monthly maximum (Tmáx) air temperatures, in the State of Rio Grande do Sul, to the normal, log-normal, gamma and weibull probability distributions, to determine probabilities of occurrence and prepare maps with the interpolation of isolines. The Kolmogorov-Smirnov test was applied to 216 time series of Tmín and 216 time series of Tmáx (18 cities × 12 months). Based on the normal distribution, values of Tmín were determined, whose probability of occurrence of Tmín less than or equal to this value is 90%, and values of Tmáx, whose probability of occurrence of Tmáx greater or equal to this value is 90%. From these values, maps were prepared with interpolation of isolines with a difference of 0.5°C. The Tmín and Tmáx data adjust the normal, log-normal, gamma and weibull distributions, showing better adherence to the normal distribution. The maps with the isolines are useful to verify the probability of occurrence of harmful or favorable Tmín and Tmáx for agricultural crops in the State of Rio Grande do Sul, during the months of the year. [ABSTRACT FROM AUTHOR]

The objective is to identify monthly and annual variations and trends in meteorological variables: maximum and minimum air temperatures, precipitation, relative humidity, number of rainy days, total sunshine, wind intensity and cloud cover. We used the theoretical probability distribution: Weibull, Log-normal and Logistics for the adjustment of the values of the aforementioned variables. The Kolmogorov-Smirnov test was used to verify the adjustment of the theoretical functions. The data used were acquired from the National Meteorological Institute, comprising the series from the period 1962 to 2015. For the determination of the theoretical distributions of probability adjusted to the annual extremes of the data under study, we used the maximum likelihood methods to estimate the parameters of distributions. The Kolmogorov-Smirnov test was used to compare the fit and select the best theoretical distributions. The adjustments were also evaluated in graphs. The deforestation of native vegetation for the construction of districts, favelas and buildings over six floors has recorded urban impact, high incidences of fires in the surrounding areas, high desertification rates, silting of rivers, streams, wells, cacimba, lakes, ponds has led to the lowering of the water table and reducing the volume of groundwater. The Weibull and Logistics distributions were the best fit for precipitation, insolation, relative humidity, minimum temperature and cloud cover. [ABSTRACT FROM AUTHOR]

The study of monthly rainfall probabilities is of great importance due to the increasing occurrences of extreme events in different regions of Brazil. However, the rainfall distribution at the southwest region of Paraná State, Brazil, is still unknown. Thus, the aim of this work is to assess the probabilistic distribution of rainfall frequency at Dois Vizinhos, in the southwest of Paraná State, Brazil. A probabilistic analysis was performed using a historic 40-year rainfall dataset (1973-2012). The gamma, Weibull, normal log, and normal probability distributions were compared. The distribution adherence was performed through Akaike Information Criterion, and the R statistical software was used for estimation. The results showed that the gamma and Weibull distributions were most suitable for probabilistic fitting. Based on this, the average annual rainfall for Dois Vizinhos (PR) was found to be 2,010.6 mm. Moreover, we found that throughout the year, October has the highest rainfall occurrence probability, with an 86% rainfall probability of above 150 mm and 64% rainfall probability above 200 mm. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a table of probabilities of occurrence of monthly values of atmospheric pressure in millibars, to Natal, RN, Brazil, from the daily records of atmospheric pressures obtained at the Meteorological Station of the Federal Rural University of the Semi-Arid in Mossley, RN, referring to a historical series thirty-eight-years (1970-2007). The atmospheric pressure in millibars monthly was estimated using the model distribution normal probability density to levels of 1% to 95% probability. Try into account the results of the compliance tests at 10% probability and using the logarithm of Maximum Likelihood, we can conclude the suitability of the construction of the table of probabilities, and that this is an important benefit in the planning of agricultural activities in the region, making the most its benefits and avoid its harmful effects. [ABSTRACT FROM AUTHOR]