The role of discharge variability in determining alluvial stratigraphy

 

Autores
Nicholas, Andrew P.; Sambrook Smith, Gregory H.; Amsler, Mario Luis; Ashworth, Philip J.; Best, James L.; Hardy, Richard J.; Lane, Stuart N.; Orfeo, Oscar; Parsons, Daniel R.; Reesink, Arnold J.; Sandbach, Stevend D.; Simpson, Christopher J.; Szupiany, Ricardo Nicolas
Tipo de recurso
artículo
Estado
Versión publicada
Año de publicación
2015
País
Argentina
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio
CONICET Digital (CONICET)
Descripción
We illustrate the potential for using physics-based modeling to link alluvial stratigraphy to large river morphology and dynamics. Model simulations, validated using Ground Penetrating Radar data from the Río Paraná, Argentina, demonstrate a strong 30 relationship between bar-scale set thickness and channel depth, which applies across a wide range of river patterns and bar types. We show that hydrologic regime, indexed by discharge variability and flood duration, exerts a first-order influence on morphodynamics and hence bar set thickness, and that planform morphology alone may be a misleading variable for interpreting deposits. Indeed, our results illustrate that rivers evolving under contrasting hydrologic regimes may have very similar morphology, yet be characterized by marked differences in stratigraphy. This realization represents an important limitation on the application of established theory that links river topography to alluvial deposits, and highlights the need to obtain field evidence of discharge variability when developing paleoenvironmental reconstructions. Model simulations demonstrate the potential for deriving such evidence using metrics of paleocurrent variance.
Idioma
inglés
OAI Identifier
oai:ri.conicet.gov.ar:11336/28326
Enlace del recurso
http://hdl.handle.net/11336/28326
Nivel de acceso
Acceso abierto
Materia
ALLUVIAL STRATIGRAPHY
DISCHARGE VARIABILITY
GPR
PARANA RIVER
Oceanografía, Hidrología, Recursos Hídricos
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS