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Application of GPR in the Study of a Modern Alluvial Megafan: The Case of the Taquari River in Pantanal Wetland, West-Central Brazil

  • Jorge Luís PorsaniEmail author
  • Mario Luis Assine
  • Leandro Moutinho
Article

Abstract.

A novel and timely ground penetrating radar (GPR) survey has been carried out in Pantanal from Mato Grosso State, west-central Brazil. Fieldwork was carried out on February/2001 and August/2002 in an attempt to understand avulsion processes that are occurring within Taquari alluvial megafan. The main objectives were to map channel, crevasse and floodplain morphology, as well as active sedimentary bedforms. Many GPR profiles were acquired in the medium and lower Taquari River course. Subaqueous megaripples and exposed sand bars were identified in the medium fan area. Similar features were observed in the lower fan channels, where there were many crevasses in the marginal levees. During the flooding seasons, the flow splays out on to the floodplain, where new distributary channels are being formed. GPR data show that the lower fan, Taquari channel is topographically higher than the adjacent floodplain, thus favoring avulsion as a natural process of river course shifting. GPR data obtained during the wet and dry seasons, together with sedimentology information have been very important in characterizing the fluvial dynamics, and avulsion phenomena.

Keywords

GPR ground penetrating radar avulsion Taquari river Pantanal wetland Brazil 

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Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • Jorge Luís Porsani
    • 1
    Email author
  • Mario Luis Assine
    • 2
  • Leandro Moutinho
    • 3
  1. 1.Departamento de Geofísica, Instituto de Astronomia Geofísica e Ciências Atmosféricas (IAG)Universidade de São Paulo (USP)São PauloBrazil
  2. 2.Departamento de Geologia Aplicada, Instituto de Geociências e Ciências Exatas (IGCE)Universidade Estadual Paulista (UNESP)Rio ClaroBrazil
  3. 3.Pós-Graduação em Geofísica, Instituto de Astronomia Geofísica e Ciências Atmosféricas (IAG)Universidade de São Paulo (USP)São PauloBrazil

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