EDITORIAL
Hydro-geomorphology, sediment transport and human impact in large South American Rivers: Preface
Edgardo M. Latrubesse 1 and Jose C. Stevaux 2
1 University of Texas at Austin Department of Geography and the Environment Austin TX, USA.
2 Universidade Estadual de Maringá. GEMA - Grupo de Estudos do Meio Ambiente. Maringa, PR, Brazil.
Received: February 23, 2010 - Accepted: March 31, 2010.
The research on the hydro-geomorphology,
sediment transport and human impact of large
rivers has recently increased in South America.
The GLOCOPH (Global Commission on Continental
Paleohydrology) Working Group on Large Rivers
chaired by us, organized Symposiums and Field
Conferences on key large fluvial systems since 1997
such as the Paraná (1997 and 2006), the Araguaia
(1999) and the Amazon (2003). Presently, the activities
of GLOCOPH are also linked to TERPO (Terrestrial
Processes, Deposits and History) Program supported
by the Commission of INQUA- Focus area group
Hydrological change and climate. Additionally, joint
efforts were made with the IGCP Project 518 Fluvial
sequences as evidence for landscape and climatic
evolution in the Late Cenozoic and two important
meetings were organized in China and Brazil during
2006 when the Paraná River Field Conference, an
activity related to the GLOCOPH International
Symposium, was held at Guarulhos.
Additionally, a special session on Large Rivers
took place at Goiania, Brazil, during the Regional
Conference on Geomorphology, an official activity of
the International Association of Geomorphologists
(IAG) at which 700 researchers from 25 countries
met.
Presently, together with our colleagues Rajiv
Sinha (India) and Z. Chen (China), we are the
leaders of the project IGCP 582 UNESCO, Tropical
Rivers: hydro-physical processes, impacts, hazards
and management and chairs of the working group
Tropical rivers of the International Association of
Geomorphologists (IAG).
In relation to the activities mentioned above we chaired in 2009 a special session on Quaternary
and Geomorphology of Large Rivers during the
Brazilian-Argentinean Congress of Quaternary and
Geomorphology that took place in La Plata, Argentina,
and that was organized by the Brazilian Association of
Quaternary Research (ABEQUA) and the Argentinean
Association of Quaternary and Geomorphology
(AACG). At the same time we offered an international
field trip linked to the RCEM 2009 International
Symposium on River Coastal and Estuarine Morphodynamics
held at Santa Fé, Argentina.
The main objective we have been trying to reach
organizing this set of activities mentioned above had
been to increase the collaborations among research
groups from several countries of Latin America.
In this sense, from 2003 to 2007 we founded the
CYTED XIIK-CABAH Network Abiotic control of
vegetation in continental wetlands and more recently
the PROSUL-CNPq project Hydro-physic responses
of large South American rivers to the global change.
The present special issue is part of the contributions
of the IGCP 582 UNESCO Tropical rivers projects
and the PROSUL-CNPq- Large Rivers network.
Five papers with results from Brazil and Colombia
are presented. J.D. Restrepo, A. Lopez and J.C.
Restrepo analyze the effects of geomorphic controls
on sediment yield in the Andean rivers of Colombia.
N. Filizola and collaborators presents results on
the Middle Amazon showing how local conditions
can affect the estimations of sediment transport.
The particular morphologies and fluvial dynamics
observed in river confluences are discussed for the
Upper Parana basin by J.C. Stevaux and collaborators.
Also in the upper Paraná D. Martins, J. P. Bravard and J.C. Stevaux estimated the rates of bed load sediment
transport after the constructions of the huge dam of
Porto Primavera. Finally S. Aquino, E. Latrubesse and
M. Bayer present estimations of wash load transport
in an understudied large tropical river, the Araguaia,
located in Central Brazil.
Considering that 24 of the 34 largest tropical
rivers of the world in water discharge are located in
South America we are sure that our contribution is
almost insignificant in relation to the potential for
research that our continent offers. While we have
been repeating concepts and examples produced on
remote areas, mainly from the northern hemisphere
- which are badly applicable to our physical reality, geomorphology in our countries has been neglected
as a main discipline of Earth Sciences either in
Geology and Geography courses. We expect in a near
future having a new generation of young researchers
capable of produce new concepts from our own
South American research, helping our societies to
obtain a more sustainable and fair use of our water
resources.
We especially thank the contributors of this issue
and the referees that helped us to obtain a better
product. Additionally we want to thank Dr. G. Perillo,
former editor of the LAJSBA and the current Editor
Dr. G. Veiga, for their support and for encouraging us
to produce this issue.