Funções densidade de probabilidade para estimação de veranicos no município de Lavras, MG

Abstract

Knowledge on the duration, quantity and distribution of rainfall is fundamental in the management of water resources, water erosion and for planning agricultural crops. The veranico, phenomenon characterized by interrupting periods of rainfall during the rainy season, presents direct influence on the productivity agricultural crops, especially when this period coincides with phase in which the plant is more sensitive to water deficiency. In this work we evaluated the potential of using exponential probability, gamma, Gumbel, lognormal, Pareto and Weibull distributions in modeling the veranico periods in the municipality of Lavras, Minas Gerais, Brazil, in addition to identifying the frequency of occurrence, duration and average period of this phenomenon. We used real data from a historical series of daily precipitation, collected between 01/01/1970 and 12/31/2010, evaluating the occurrence and duration the veranico periods obtained from rainfall records of the Estação Climatológica Principal de Lavras, Minas Gerais, located on the Universidade Federal de Lavras campus, in Lavras, in an agreement with the Instituto Nacional de Meterologia (INMET). The adherence of the estimated probabilities of the frequencies observed was verified via the Kolmogorov-Sminorv test. With the exception of the Pareto and exponential distributions, all the analyzed distribution presented adherence to the occurrence of veranicos. However, the results obtained indicated that the lognormal model adjusted more adequately to the data observed.