Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modelling
<p>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 detaile...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2019-11-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://www.nat-hazards-earth-syst-sci.net/19/2421/2019/nhess-19-2421-2019.pdf |
| _version_ | 1818300748616695808 |
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| author | V. Baumann C. Bonadonna S. Cuomo M. Moscariello S. Biass M. Pistolesi A. Gattuso |
| author_facet | V. Baumann C. Bonadonna S. Cuomo M. Moscariello S. Biass M. Pistolesi A. Gattuso |
| author_sort | V. Baumann |
| collection | DOAJ |
| description | <p>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.</p> |
| first_indexed | 2024-12-13T05:12:03Z |
| format | Article |
| id | doaj.art-b8734f66109f408992d515c1a7091386 |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-12-13T05:12:03Z |
| publishDate | 2019-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-b8734f66109f408992d515c1a70913862022-12-21T23:58:30ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812019-11-01192421244910.5194/nhess-19-2421-2019Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modellingV. Baumann0C. Bonadonna1S. Cuomo2M. Moscariello3S. Biass4M. Pistolesi5A. Gattuso6Department of Earth Sciences, University of Geneva, Rue des Maraîchers 13, 1205 Geneva, SwitzerlandDepartment of Earth Sciences, University of Geneva, Rue des Maraîchers 13, 1205 Geneva, SwitzerlandLaboratory of Geotechnics, University of Salerno, Via Giovanni Paolo II 132, 84081 Fisciano Salerno, ItalyLaboratory of Geotechnics, University of Salerno, Via Giovanni Paolo II 132, 84081 Fisciano Salerno, ItalyEarth Observatory of Singapore, Nanyang Technological University, Singapore, SingaporeDipartimento di Scienze della Terra, Università di Pisa, Pisa, ItalyIstituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Italy<p>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.</p>https://www.nat-hazards-earth-syst-sci.net/19/2421/2019/nhess-19-2421-2019.pdf |
| spellingShingle | V. Baumann C. Bonadonna S. Cuomo M. Moscariello S. Biass M. Pistolesi A. Gattuso 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 |
| title | Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modelling |
| title_full | Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modelling |
| title_fullStr | Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modelling |
| title_full_unstemmed | Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modelling |
| title_short | Mapping the susceptibility of rain-triggered lahars at Vulcano island (Italy) combining field characterization, geotechnical analysis, and numerical modelling |
| title_sort | mapping the susceptibility of rain triggered lahars at vulcano island italy combining field characterization geotechnical analysis and numerical modelling |
| url | https://www.nat-hazards-earth-syst-sci.net/19/2421/2019/nhess-19-2421-2019.pdf |
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