Stochastic modeling of reference evapotranspiration in arid and semi-arid zones

Abstract

The objective of this work was to estimate the probabilities of the reference evapotranspiration (mm), as well as its accumulated values during 10 days (decendial), in Mossoró, RN, Brazil. It wass done through the daily records of evapotranspirations obtained at the Meteorological Station of the Federal Rural University of Semi-Arid (UFERSA), in Mossoró, RN, using the Penman-Monteith method. No previous transformation of the data was necessary since the construction of the tables was based on the approximation of the variable to the Normal distribution. The odds were estimated by the Normal distribution for the confidence levels of 1% to 95% in the data period from 1970 to 2007, taking into account the results of the chi-square and Kolmogorov-Smirnov tests at 10% probability. From the adequacy of the process of construction of the tables, it can be conclude and that studied values have important subsidies for planning of agricultural activities in the region, where the maximum benefits of their benefits are taken, avoiding their harmful effects.