Strong seasonality in sand loading and resulting feedbacks on sediment transport, bed texture, and channel planform at Mount Pinatubo, Philippines

Auteur(s) et Affiliation(s)



Description :
The effects of episodic sand loading are explored through flow, grain size, and bedload transport measurements on the Pasig-Potrero River, a sediment-rich channel draining Mount Pinatubo, Philippines. Sand loading on the Pasig-Potrero River is highly seasonal, and channel adjustments between seasons are dramatic. During the fall 2009 seasonal transition, 7.6 km of channel incised and armored, carving a 2-3 m deep channel on the upper alluvial fan. Bedload transport rates measured in the August 2009 rainy season were over 4 orders of magnitude greater than gravel-bedded dry-season channels surveyed in January 2010, despite having similar shear stress and unit discharge conditions. Within dry-season incised channels, bed armoring is rapid, leading to an abrupt gravel-sand transition. Bedload transport rates adjust more slowly, creating a lag between armoring and commensurate reductions in transport. Seasonal channel incision occurred in steps, aided by lateral migration into sand-rich banks.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2012, vol. 37, n°. 9, p. 1012-1022, nombre de pages : 11, Références bibliographiques : 1 p.

Date :
2012

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley