Formação e evolução morfológica de barras e ilhas em rios semiáridos: o contexto do baixo curso do Rio Jaguaribe, Ceará, Brasil

Abstract

This study deals with the morphological evolutionary formation of bars and islands in the lower reaches of the Jaguaribe river, particularly without a segment downstream of the Castanhão dam, in dry and rainy years. Methodologically, we used the determination of dry and rainy standard years, the use of remote sensing tools, through the use of aerial photographs and geoprocessing software to map the different typologies of bars and river islands. The results indicated that the formation of these features reflects the flow and precipitation variations in the lower Jaguaribe river, as evidenced by the data of Pearson's linear correlation coefficient and the coefficient of determination, that is, in the years considered dry there was a due to the absence of significant flows to promote sediment transport, whereas, in rainy years, there was an increase in bars, mainly due to the cyclical action of the erosive and sedimentary processes that promote the distribution and redistribution of the sediments in the channel.