Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/137232
Title: Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modelling
Authors: Baumann, Valérie
Bonadonna, Costanza
Cuomo, Sabatino
Moscariello, Mariagiovanna
Biass, Sebastien
Pistolesi, Marco
Gattuso, Alessandro
Keywords: Science::Geology
Issue Date: 2019
Source: Baumann, V., Bonadonna, C., Cuomo, S., Moscariello, M., Biass, S., Pistolesi, M., & Gattuso, A. (2019). Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modelling. Natural Hazards and Earth System Sciences, 19(11), 2421-2449. doi:10.5194/nhess-19-2421-2019
Journal: Natural Hazards and Earth System Sciences
Abstract: The characterization of triggering dynamics and remobilized volumes is crucial to the assessment of associated lahar hazards. We propose an innovative treatment of the cascading effect between tephra fallout and lahar hazards based on probabilistic modelling that also accounts for a detailed description of source sediments. As an example, we have estimated the volumes of tephra fallout deposit that could be remobilized by rainfall-triggered lahars in association with two eruptive scenarios that have characterized the activity of the La Fossa cone (Vulcano, Italy) in the last 1000 years: a long-lasting Vulcanian cycle and a subplinian eruption. The spatial distribution and volume of deposits that could potentially trigger lahars were analysed based on a combination of tephra fallout probabilistic modelling (with TEPHRA2), slope-stability modelling (with TRIGRS), field observations, and geotechnical tests. Model input data were obtained from both geotechnical tests and field measurements (e.g. hydraulic conductivity, friction angle, cohesion, total unit weight of the soil, and saturated and residual water content). TRIGRS simulations show how shallow landsliding is an effective process for eroding pyroclastic deposits on Vulcano. Nonetheless, the remobilized volumes and the deposit thickness threshold for lahar initiation strongly depend on slope angle, rainfall intensity, grain size, friction angle, hydraulic conductivity, and the cohesion of the source deposit.
URI: https://hdl.handle.net/10356/137232
ISSN: 1561-8633
DOI: 10.5194/nhess-19-2421-2019
Rights: © 2019 Author(s). This work is distributed under the Creative Commons Attribution 4.0 License.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:EOS Journal Articles

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