Reducing Risk from Lahar Hazard in Volcanic Catchment: Retarding Basin Site Assessment

DOI

10.2991/icge-16.2017.11How to use a DOI?

Keywords

Retarding basin, lahar, flash flood, volcanic catchment

Abstract

Indonesia poses as a country with the highest risk of natural disaster in Southeast Asia. With no less than 130 active volcanoes, volcanic eruption and lahars as the secondary hazard become inevitable. Major damage and casualties had been reported, thus encourage more proper mitigation measures to be applied. This study propose a retarding basin as a possible measure to decrease the magnitude of lahars by providing runoff control function as a reservoir containing a substantial volume of water at a predetermined conservation pool level. The aim of this study is to discuss the best location for retarding basin to retain stormwater during lahars and flash flood occurrence. A case study of Bladak catchment in Kelud volcano is taken. There are three main parameters used to determine the most proper retarding basin sites in this study, such as soils, slope, and land cover. The soils in Bladak catchment is classified in Hydrological Soil Group (HSG) as type A, while its topographic features and land cover are more varied. Taking into account river gradient of Bladak river and the positions of existing sabo dams cannot be separated from the spatial analysis of the topography and land cover to produce suitable areas for retarding basin installation. The retarding basin may pose as an effective mitigation measure for lahars and flash flood in volcanic slope since it also has functions of water quality and quantity control in addition to ecological function as a green area. By placing retarding basin in the secondary channels before they join into the primary channel, it is expected to reduce the magnitude of rapid accumulation streamflow following storm events.

Copyright

© 2017, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Alzaena Ulya Rusdimi
AU  - Junun Sartohadi
AU  - Su Ritohardoyo
PY  - 2016/11
DA  - 2016/11
TI  - Reducing Risk from Lahar Hazard in Volcanic Catchment: Retarding Basin Site Assessment
BT  - Proceedings of the 1st International Conference on Geography and Education (ICGE 2016)
PB  - Atlantis Press
SP  - 57
EP  - 61
SN  - 2352-5398
UR  - https://doi.org/10.2991/icge-16.2017.11
DO  - 10.2991/icge-16.2017.11
ID  - UlyaRusdimi2016/11
ER  -