Estimativa do balanço hídrico para as condições climáticas iguatu, ceará, usando modelo estocástico

Abstract

This paper had the objective of estimating the parameters of the Gamma Distribution adjusted to the precipitation and monthly evapotranspiration data of the Iguatu region as well as to estimate the monthly water deficits and excesses, through the application of probabilistic models in different levels of probability. This work was carried through using the series of data in a daily basis between 1961 and 2005. The data was collected at the Main Climatological Station of Iguatu, pertaining to the meteorological net of the National Institute of Meteorology (INMET). For each database the parameters α and β of the Gamma Distribution were determined for the precipitation probability and monthly evapotranspiration. The data adjustment was verified through the Chi-Square test at the of 5% level of significance. For each analyzed probabilistic level, a monthly water balance it was obtained, using the available water capacity as being 100 mm. To the level of 75% of probability, there was a need to replace 132.5 mm of water since July up to 176.5 mm in November, with totals of 335.4 mm in the first semester and 967.7 mm in the second semester and 1303.1 mm throughout the year.