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Universidade Federal do Rio Grande do Norte (UFRN) 2022

Estudo climatológico e análise da frequência de "dry spell" para o semiárido brasileiro

Medeiros, Biancca Correia de

Titre : Estudo climatológico e análise da frequência de "dry spell" para o semiárido brasileiro

Auteur : Medeiros, Biancca Correia de

Université de soutenance : Universidade Federal do Rio Grande do Norte (UFRN)

Grade : Doutorado em Ciências Climáticas 2022

Résumé
Climatic variations directly influence the economy of a region. This scenario in the Brazilian semiarid region can be even more impactful, considerably affecting agriculture and water resources. Thus, the general objective of this study was to analyze possible climate changes existing for four sub-regions of the Brazilian Semiarid of the meteorological parameters such as precipitation, minimum and maximum temperature, humidity and insolation during the period from 1962 to 2019. Daily precipitation data were used, minimum and maximum temperature, humidity and insolation from the Meteorological Database for Teaching and Research (BDMEP) of the National Institute of Meteorology (INMET) of 72 stations located in the Brazilian semiarid region. Among the statistical methods, the Mann-Kendall test was used to verify possible trends, increasing or decreasing at a significance level of 5%, the statistical technique of multivariate analysis of variance (MANOVA) to perform a spatiotemporal analysis, comparing the means of the parameters between the periods, and two distributions for count data, the Zero Inflated Poisson - ZIP and the Zero Inflated Negative Binomial - ZINB to analyze the frequency of "dry spell", and make a comparison in relation to quality adjustments through two criteria, AIC and BIC. The results of the trend analysis indicated a decreasing trend for precipitation in all regions during the period 1962-2019. A trend of increasing maximum temperature was observed for almost all regions, except the R2 region and decreasing of minimum temperature in all regions. The insolation had a different variation by region, R1 and R4 showed increasing insolation while R2 and R3 decreased. The results of the multivariate analysis (MANOVA) indicated significant changes (p-value < 0.05) in all variables. On average, the values of precipitation and humidity between the periods (1962–1990 and 1991–2019) decreased, while the values of maximum, minimum and insolation temperatures increased. When comparing the adjustments of the two models, the Zero Inflated Poisson (ZIP) model had the best fit to the data. The results of this study allow the assessment of possible climate change on the Brazilian semiarid region between the two analyzed periods, also contributing to future studies on the vulnerability of this region, as well as the elaboration of decision-making focused on mitigating the effects of these climate changes. With the adjustment of the model, it will be possible to predict the occurrence of the dry period for the Brazilian semi-arid region and thus be able to reduce the impacts of this phenomenon on agricultural productivity.

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Page publiée le 18 janvier 2023