Determinação dos parâmetros da distribuição gama e média pluviométrica decendial para estações do estado de mato grosso

Abstract

Mato Grosso is among the largest grain producers of Brazilian's States and it is responsible for some of the commodities that the country exports and these are dependent on rainfall. Considering these facts, the present study aimed to determine the parameters of the Gamma distribution probability related to precipitation measurements on 43 stations, in periods of ten days, to provide information to estimate the probability of a minimum expected 10 days precipitation. A great spatial and temporal variability of the measured 10 days precipitation along the State was reported. Estimates of the shape (γ) and scale (β) parameters varied from 0.01 to 120.7 and from 0.01 to 336.0 respectively. The parameters "γ" and "β" of the Gamma Distribution can be used to determining the expected 10 days precipitation, and the periods with higher rainfall, are between the months from November to March. The Northward stations of the State have the greatest 10 days precipitation while those Southward, have lower values.