The Madeira River, the largest tributary in water discharge and sediment transport of the Amazon basin, will be dammed by the end of 2012. This project will collect hydrogeomorphologic and hydraulic information before human intervention. The main objectives are to a) analyze the fluvial morphodynamics to understand the mechanism controlling the development of anabranching patterns in this megariver (this information will serve as baseline for examination of anthropogenic effects); b) identify the geoenvironmental mosaic of the floodplain and the morphosedimentary processes controlling its evolution and architectural style, and c) provide predictive mathematical tools and generate new concepts for management of anabranching rivers. The field work in Brazil, using research vessel-based surveys from Porto Velho to Humaita, will span the Madeira's flow before regulation, with surveys during low and high water stages.
This project provides a unique and last opportunity to study the dynamics and morphology of the largest tributary of the Amazon River before it is dammed. The researchers will collaborate with Brazilian colleagues on two expeditions in 2012--at low water and high water. In addition to providing rare insights into the workings of so-called "Mega-rivers", the results and data base obtained from these expeditions will be fundamental for assessing and modeling the short and medium-term impacts of the dam on the Amazon and the Amazon plume as a result of the alteration of sediment and water fluxes. The project will support the interdisciplinary education and training of graduate and undergraduate students, and its results are expected to inform Brazilian and international institutions involved in environmental management in the Amazon basin.
The Madeira River , the largest tributary in water discharge and sediment transport of the Amazon basin is center to a controversial political and environmental discussion because the Brazilian government have been constructing huge hydropower sequential plants that, irremediably, will produce river regulation. Recently there have been concerted efforts to unite theories and conceptual approaches emerging from the overlap of subject areas of the disciplines of geomorphology, ecology, fluvial engineering and hydrology in order to better understand streams and rivers in a holistic manner. Accordingly, we assembled a team with skills in geomorphology, river hydraulics, environmental impact assessment, fluvial engineering and hydrology. The project involved PIs from the University of Texas at Austin and University of Pittsburgh, graduate and undergraduate students, two senior collaborators from Brazil, and triggered a strong USA-Brazilian cooperation. Our combined approach applying intense field work, multiple proxies, the use of hydrological, hydraulics and sedimentologic techniques and equipment and the application of advanced remote sensing technologies provided new insights into the mechanisms conditioning the morphodynamics of mega-rivers, the generation of anabranching patterns, the hydraulic conditions of sediment transport, channel adjustments and patterns of sediment flows.Our results are providing theoretical and conceptual insights on the morphodynamics conditions that trigger the irreversible adoption of anabranching styles by mega-rivers. In relation to applied science and transverse interaction across disciplines, the hydro-geomorphological data set with information on the Madeira will be available to Brazilian and international institutions to influence environmental management and future trends in environmental and water resource policies and programs in the Amazon basin. Our results and data base are a fundamental tool for assessing and modeling the short and medium term impacts that will suffer the Amazon and the Amazon plume because the alteration of sediment and water fluxes.
