Drainage shift as response to morphological feature: analysis of Dourado Stream, Parana - Brazil

Abstract

The study of rivers adjustment induced by changes in clime, hydrology, tectonics and even by human beings, contribute to the understanding of the evolution process of fluvial landscape. This work aims to analyze an abrupt change on the drainage orientation of the Dourado Stream and it´s tributary the Ivai River. The study area is located on the northwest of the Paraná State- Brazil, near to the confluence of the Ivai and Paraná Rivers. The shift in the stream orientation occurred when the channel started to flow over the floodplain built up by the Paraná and Ivai Rivers. The analysis was performed using remote sensing data, like orbital and aerial images, where we applied visual interpretation, trend surface technique and analysis of residual elevation data. A field work was conducted to ground-truth the results. We concluded that the orientation floodplain, where part of channel passes through, there was a discordance of direction from drainage to the Dourado Stream. The paleochannel identification on the plain highlighted that the drainage orientation is controlled by its morphology.