Estudo de secas climatológicas no Nordeste do Brasil.

Abstract

Climatological droughts were studied in 15 localities of Northeastern Brazil based on precipitation time series and air temperature. The components of normal and series water balance were used to identify climate types, temporary climate changes and drought years, the latter according to the deviation of the aridity index from the median. Aspects of intensity and duration of some drought situations were studied using monthly water deficit values. Statistical analysis of the R index was performed through the Beta distribution. It has been found that identifying drought based on rainfall alone data can lead to compromising results. There is not necessarily a correlation between occurrences of drought and temporary climate change in a given locality. The humidity regime of the localities with normal climate type C1 or C2 was very unstable. From a practical point of view the Beta model proved to be very suitable as a probabilistic model to represent monthly values ​​of the R index.