Author(s): Adriano Coutinho de Lima

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Keywords: Waterway; Large river; Tropical river; River morphodynamics; Hydrology

Abstract: The Tocantins and Araguaia are large rivers located in central-northern Brazil and their history as a waterway is to some extent comparable to that of the Mekong River. Historically important as a transportation network, the Tocantins-Araguaia Waterway had its significance diminished in the 20th century with the advent of other modes of transportation. In recent years, however, it is being restructured as a competitive alternative for reducing logistic costs and boosting economic growth. Although large rivers often exhibit long navigable extensions, navigation may be interrupted by natural obstacles such as shallows, rapids and rock protrusions. Tropical rivers, in particular, exhibit considerable variations on the discharge, water level and velocity along the year in line with their typical rainy and dry seasons, which poses additional constraints for navigation. Interventions which require strict environmental assessment are thus often necessary for converting rivers into competitive waterways. In this work, morphodynamic and hydrological characteristics of the Tocantins-Araguaia system are studied and proposed and existing engineering interventions on these two rivers are reviewed. A parallel is traced with other waterways in large tropical rivers in Brazil, where long term morphological impacts of fluvial interventions, particular dams, have been reported, such as destabilization of the mouth of the Sao Francisco River.

DOI:

Year: 2018