Using the average directions of the main wave-fronts which approach the coast of Bahia State -coinciding with that of the main wind occurring in the area -and of their periods, we define a wave climate model based on the construction of refraction diagrams. The resulting model of sediment transport was able to reproduce, in a general way, the sediment dispersion patterns furnished by geomorphic indicators of the littoral drift. These dispersion patterns control the generation of different types of sediment accumulations and of coastal stretches under erosion. We demonstrate that the presence of the Abrolhos and Corumbaú Point coral reefs is an important factor controlling the sediment dispersion patterns, since them act as a large protection against the waves action. key words: Littoral drift, wave refraction, numerical modelling, State of Bahia, Brazil.
Hydrogeochemical diagrams and multivariate statistics were applied herein to identify the factors that potentially influence the salinity of water in the crystalline aquifer of the Cachoeira River Basin region, located in the southern portion of the State of Bahia. Data from the hydrogeological database of the Companhia de Engenharia Hídrica e de Saneamento da Bahia (CERB) were applied. The groundwater was predominantly classified as calcium-bicarbonate, with salinity levels ranging from fresh to brackish. The cation that prevails in the region is Ca2+, while carbonate and bicarbonate are the dominant anions. Factor analysis enabled the determination of two factors that explain approximately 93% of the total variance of the data. Hierarchical cluster analysis resulted in five distinct groups based on dissolved ion concentrations. This study indicates that the natural mechanisms that control the chemical composition of groundwater are mainly related to the weathering of rocks and evaporative processes, with the most significant parameters related to the variability of water salinity being Ca2+, Mg2+, K+, Fe (total), and Cl-.
Este estudo tem como objetivo identificar tendências e variabilidade pluviométricas na Bacia Hidrográfica do Rio Cachoeira, região Nordeste do Brasil. Os dados utilizados compreendem séries históricas de precipitações totais mensais de seis estações pluviométricas para o período de 1970 a 2020 (51 anos) obtidos no Sistema de Informações Hidrológicas (HidroWeb) da Agência Nacional de Águas e Saneamento Básico (ANA). Os testes de Mann-Kendall, Spearman’s Rho e Sen’s slope foram aplicados de maneira satisfatória, permitindo a identificação de tendências significativas e magnitude da precipitação. A análise mostrou que tendências estatisticamente não significativas prevalecem na área. Contudo, foi identificada expressiva tendência negativa na região Centro-Oeste em duas estações pluviométricas que caracterizam redução em torno de 300 mm de chuva no período estudado. Períodos com extremos de seca/umidade foram reconhecidos e comparados com as fases do El Niño Oscilação Sul (ENOS), em que se identificou que 62,5% dos eventos de seca e 42,9% dos eventos chuvosos podem ser relacionados com os fenômenos El Niño/La Niña, respectivamente. Com o coeficiente de variação, foi reconhecida baixa variabilidade da precipitação na porção leste e elevada variabilidade na parte oeste da área. Os resultados obtidos podem ser utilizados como referência para a gestão de recursos hídricos na bacia hidrográfica.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.