Abstract

This article focuses on evaluating erosion process changes in Brazil using hydrologic and hydro-sedimentologic studies accomplished in great river basins of the Country. Firstly, it was studied the precipitation and water flow changes in the basins. After that, it was studied the sediment budget changes in the rivers. The results indicated that the amount of rain increased in several areas and, consequently, the same behavior was verified analyzing the water flow. In most of the stations in which a precipitation and water flow increase was verified, there was also an augmentation in the sediments transport. It is important to notice that, as the correlation between precipitation and water flow approaches more to a linear form than the one observed between water flow and sediment yield, that is usually potential, the variation taxes of the sediments flow are generally amplified in relation to the one of the water flow. There were cases in which, even with a reduction of the water flow during the analyzed period, it was verified an increment of the sediment yield, indicating that, probably, human activities in the basin have increased their erosion taxes significantly.

Keywords: Rainfall, river flow, sediment discharge.