ANÁLISE MORFOLÓGICA DO BAIXO CURSO DO RIO CUBATÃO, EM JOINVILLE (SC), NO PERÍODO ENTRE 1938 E 2015: IMPACTO DE BARRAGEM NA MORFODINÂMICA FLUVIAL

Abstract

The objective of this work was to analyze the impact of fluvial morphology on the construction of a dam and the derivation channel in the lower course of the Cubatão River, located in northeastern Santa Catarina state. The multitemporal analysis was based on aerial photographs and satellite images from the years 1938, 1953, 1966, 1996, 2010 and 2015. The drainage channels of each year were delineated, followed by the calculation of their sinuosity and mapping of the meanders and bars. Finally, two scenarios of stream power index were modeled: one considering the natural bed and the other just the derivation channel. The construction of the dam and the derivation channel that divided the flow of the Cubatão River in the 1950s, the results exposed the morphological and morphodynamic alterations on the river, with an increase in sinuosity of 4.7% in the segment, occupied by the riverbed (44%) and the decrease of 78% of the area occupied by bars. It is emphasized that there was a marked increase in the sinuosity of the river between 1953 and 1966. Next to the mouth, inversely, the sinuosity decreased by 2% and the area of ​​the ebb bed, prominently, increased by 16%.