RODRIGUES, E. L.; RODRIGUES, EDGLEIDSON LIMA.; http://lattes.cnpq.br/1385502892031049; RODRIGUES, Edgleidson Lima.
Resumo:
Located in the Brazilian Northeast (NEB), Paraíba presents a climatic variability, with
periods that vary from high precipitation rates to seasons of severe droughts, due to the
direct influence of elements and mechanisms that dictate the rainfall regime in this
Region. This work aimed to estimate the variability and trend of rainfall in the state of
Paraíba through the analysis of average monthly and annual precipitation in rainy and dry
periods. Records from 123 rainfall stations of AESA were considered, contemplating 27
years of observations. Basic statistics were estimated: mean, median, standard deviation,
asymmetry coefficient, kurtosis and variation. The results showed that the distribution of
rainfall occurs irregularly and with great variation throughout the year. The annual
distribution showed high spatial variability of precipitation in the central sector of the
state, with smaller values around 300 to 500 mm. In the Sertão and Alto Sertão these
values are around 700 to 900 mm. In the Brejo and Agreste of 700 to 1200 mm and in the
Litoral from 1200 to 2000 mm. The months of March and April were the wettest months
in almost the entire state and from May to August the highest precipitation totals were
concentrated in the east lane and mainly in the southern coast. September was considered
the driest month and in the rest of the year the rains occurred in an isolated way. The
values of the asymmetry coefficient (𝐶𝑠) varied greatly, but in the Zona da Mata these
values were more uniform. In almost all months of the historical series of rainfall data the
asymmetry was positive. In almost all months of the historical series of rainfall data the
skewness was positive. The peaks of the kurtosis coefficient (𝐶𝑘) were concentrated in
the central part of the state comprising January through May. From June on, the highest
values were seen in the western part of the state. The peaks of the Coefficient of variation
(𝐶𝑣) were located in the Agreste and Borborema regions, between January and April. The
Sertão was configured as the region with the greatest variation of (𝐶𝑣) during the rest of
the year. The Zona da Mata presented a practically annual homogeneity, with low
variation from January to March. In the analysis of the dry and rainy periods, the
Standardized Precipitation Indices (SPIs) were used in the time scales of 1, 3, 6 and 12
months. Between the years 1997 and 2000 droughts were verified and identified by all
the SPIs. These events were possibly influenced by the El Niño phenomenon. Noteworthy
here is the historical drought across the entire Paraíba territory in 1998, as well as the
droughts that occurred between 2014 and 2016.