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La autoorganización de los canales fluviales como un filtro crítico de las señales climáticas
Colin B Phillips1, Douglas J Jerolmack2
1St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55414, USA.
Science (New York, N.Y.)
|May 7, 2016
Resumen
Los canales fluviales se autoorganizan hasta un estado casi crítico para el transporte de sedimentos, filtrando las señales de lluvia extrema. Este proceso universal da forma a los paisajes independientemente de las influencias climáticas, tectónicas o rocosas.
Área de la Ciencia:
- Geomorfología
- Hidrología
- Sedimentología
Sus antecedentes:
- Se cree que la variabilidad de las precipitaciones impulsa la evolución del paisaje a través de la erosión fluvial y el transporte de sedimentos.
- La comprensión del vínculo entre las precipitaciones y la dinámica del río requiere el conocimiento de las retroalimentaciones del transporte de sedimentos de inundación.
Objetivo del estudio:
- Investigar la relación entre la geometría del canal del río, el flujo de la corriente y la capacidad de transporte de sedimentos.
- Determinar cómo los sistemas fluviales se adaptan a las variaciones de las precipitaciones y su impacto en la evolución del paisaje.
Principales métodos:
- Analizaron la geometría del canal y los datos de flujo de 186 ríos de grano grueso en los Estados Unidos.
- Examinó la distribución de la velocidad de corte del fluido durante los eventos de inundación.
Principales resultados:
- Los canales fluviales se ajustan universalmente a un estado en el que la velocidad de corte de la inundación excede ligeramente el umbral crítico para el transporte de sedimentos.
- Este proceso de autoorganización es independiente de los controles climáticos, tectónicos y rocosos.
- La distribución universal de la velocidad de corte indica que los canales fluviales filtran la influencia de las precipitaciones extremas en la descarga.
Conclusiones:
- La autoorganización del canal del río a un estado casi crítico para el transporte de sedimentos es un factor dominante en la evolución del paisaje.
- Este proceso amortigua el impacto de los eventos de lluvia extrema en la dinámica del paisaje, lo que lleva a una respuesta geomórfica universal.
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