1. River responses to the 2010 major eruption of the Merapi volcano, central Java, Indonesia
- Author
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Frédéric Gob, Delphine Grancher, Sandy Budi Wibowo, Edouard de Belizal, Kiki Widyaputra Primanda, Emmanuèle Gautier, Caroline Sarrazin, Franck Lavigne, Anouk Ville, Vincent Tamisier, Clément Virmoux, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches en Oncologie biologique et Oncopharmacologie (CRO2), and Aix Marseille Université (AMU)- Hôpital de la Timone [CHU - APHM] (TIMONE)-Institut National de la Santé et de la Recherche Médicale (INSERM)
- Subjects
010504 meteorology & atmospheric sciences ,Fluvial ,010502 geochemistry & geophysics ,01 natural sciences ,Aggradation ,Riverbed incision ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Hydrology ,geography ,geography.geographical_feature_category ,Vulcanian eruption ,Lahar ,Sediment ,Merapi ,Volcanic eruption ,[SHS.GEO]Humanities and Social Sciences/Geography ,Sediment transport ,Fluvial readjustment ,Opak River ,Volcano ,13. Climate action ,Progradation ,Geology - Abstract
This study examines the fluvial readjustment of a Javanese river impacted by the major eruption of the Merapi volcano (Indonesia) in October and November 2010. The basin of the Opak River, located on the southern flank of the Merapi, was subject to substantial sediment input related to massive pyroclastic deposits that were remobilized by numerous lahars during the year after the eruption. Two study sites were equipped in order to evaluate the morphodynamic evolution of the riverbed of the Opak River. Topographic surveys, bedload particle marking, and suspended sediment sampling revealed an important sediment mobilization during efficient flash floods. Surprisingly, no bed aggradation related to the progradation of a sediment wave was observed. Two years after the eruptive event, marked bed incision was observed. The Opak River readjustment differs from that of other fluvial systems affected by massive eruptions in two ways. Firstly, local population extracted the sand and blocks injected by the eruption as they represent a valuable economic resource. Secondly, several dams trapped the major part of the sediment load remobilized by lahars.
- Published
- 2016
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